F O R M 2
THE PATENTS ACT, 1970 (39 of 1970)
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION
COMPOSITES WITH VERY HIGH WEAR RESISTANCE
2. APPLICANT(S) I
(a) NAME FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG
DER ANGEWANDTEN FORSCHUNG E.V.
(b) NATIONALITY GERMAN Company
(c) ADDRESS HANSASTRASSE 27C,
80686 MUENCHEN, GERMANY

The invention refers to the field of metallurgy and ceramic composites with very high wear resistance, how they can be used for e. g parts in mining, mixing and processing equipment in contact with products, in dismantling, during transportation and further processing of ores, minerals and coals or in plants for the cement production.
The material building with highly wearing parts in mining and in preparation technology, conform especially to the plant type and to the associated constructive solution. Still question on crushing plays an important role during the selection, like the speed, the type and the shape of goods and/ or the lifetime of plants.
So far high strength materials are used for wearing bodies, whereby due to extreme stroke and shear stress only metals are worth considering, which are partially provided with hard metal or ceramic plating, shrunk bandages or exchangeable segments (Hanstein, Th: Contribution in raising the lifetime of working bodies in high compression roller mill, dissertation TU Bergakademie Freiburg 2001), which too wear out comparatively fast and then must be replaced. Often for e. g hammers, teeth or drill are made of tough steel due to their high mechanical stress, which subsequently provided by rewelding or inserting into segments made of hard metals, which always must be attached again, depending on the abrasion. This considerably increases the cost, especially on expensive welding technology. Sections of grinder with grinding tracks, grinding bodies or rollers are often cast parts, which are implemented with wear resistant cast, frequently alloyed with chrome, nickel, molybdenum or manganese. Well known representatives of such alloyed

compositions are nihard, chrome-nickel, alloyed white structured cast iron, hard cast chrome with carbon content <= 3% and chrome content <30% austenitic manganese steel with carbon content of 1.2% and manganese content of 12% (DIN EN 12513 “Wear resistant cast iron”).
All these materials have carbon as common, not as in classic grey cast iron, exists in fin or ball shapes, is bound in the shape of carbides. In spite of this high share on carbides the wearing cast tools wear out fast in micro structure, depending on the type of ground material in the grinding zone, which is accompanied by unsatisfactory lifetime. This results in considerable costs by the maintenance of costly spare parts, downtimes for the exchange and even stand for limitations by a change in the quality of ground material. For this reason, since many years various developments are known, in implementing these parts made of composites and in increasing the running time.
In an industrial largely used methods, while casting components porous preforms made of rough ceramic or hard metal particles are inserted into the later heavy wearing zones and thus infiltrated with a cast metal, where the pores in the preforms are completely filled. Thus a composite made of metal and ceramic is created, whereby in the application the ceramic now shows the wearing components and the metal fixing the ductile components. A porous preform is described as ceramic, which consists of particles with 20-80% aluminium oxide and 80-20% of zirconium oxide and manufactured by using electrofusion, sinter or spraying flame or is connected only with binders. The volume of share on ceramic is described by 35-85 percent of volume. Classic gravity casting or centrifugal casting is mentioned as

casting method. These solutions are known, especially with reference to processing grinders in various execution forms, under the brand names Xwin® and neoX® with ceramic preforms (WO98/15373) and used mainly in Magotteaux-grinder.
Disadvantage of such solution is that the previous production of ceramic in the porous preform is time consuming and expensive and these preforms show an insufficient thermos-shock resistance, based on their state, for filling with the liquid metal.
In the DE 20 2007 004 774 U1 ceramic metal matrix composites are described, in which the ceramic cake is composed of ceramic grains made of aluminium oxide and boron carbide, silicon carbide or wolfram carbide. The ceramic cake is impregnated with metal.
The use of porous hard metal-preforms is specified in the DE 10 2008 032 271 B4, in the production of composite materials. The chemical composition of hard metal is 92-80% W, Ti, Ta, Nb, V, Mo, Cr in a mixture with 8-20% Co or 85-60% of equal carbide/oxide/nitride and 15-40% Ni (all Ma. -%). These hard metals are produced by means of electron beam melting method with generative design.
On the other hand, in grinder of firm Kӧppern an armour of wearing parts is used. For that hard metals like wolfram carbide, titan carbide of chrome carbide with a grain size of > 100 µm and up to a volume share of 50% in a mixture of steel powder (for e. g 56 NiCrMoV7) is pressed by means of powder metallurgic procedure to parts, whereby there are zones in hexagonal structure in greater numbers and zones

around these made of hard metal, in smaller numbers, wherein the hard metal zones are responsible for the ductile properties of materials. Often parts produced thus in ductile shape can be applied.
Afterwards final thermal treatment takes place, during which not only the tool steel but also the hard metals get their final properties. These armouring on the parts is known as Hexadur® of firm Kӧppern (Schumacher, M., Theisen W.: Hexadur®- a novel wear protection of high pressure roller presses for comminution; machine factory KӧppernGmbH&Co.KG; No. 11,5). Disadvantage of this solution is that the production is very time consuming by the many processing steps and is not reparable for the imperfections or spalling arising while on use.
According to WO 2004/043875 A2 a composite material made of ceramic and metal or metal and ceramic is described, wherein the ceramic shares are composed of oxides or mixture of oxides like AI2O3, MgO, SiO2, TiO2, ZrO2, CrO3 or Y2O3, which again can be mixed with carbides, nitrides or borides. Additionally, Ti and/or Cr is added with maximum weight -%, as activators for the infiltration of metal alloys in metal alloys. For infiltration, iron-based or nickel-based- alloys are used. The production of compound takes place by casting the metals in the ceramic and by infiltrating into vacuum, without pressure or in gentle to medium pressure.
The disadvantage of this method lies in the necessity of use of activator, because otherwise no sufficient good or fast infiltration takes place and above all no spontaneous infiltration.

Further, a method is known for the infiltration of SiC-preforms with a diameter of 50 mm and a height of 4-6 mm and a particle size of 750 µm, which is infiltrated with grey cast iron and ductile iron and 2.5- 3 Ma-% Si. The production takes place using vacuum supported sand casting (Asano, K et al, Int. J. of cast metals Res. 2008, Vol. 21, No 1-4, page 209-213). For the porosification of preforms plastic balls are added to the SiC, to get a volume share of ceramic in the preform of 20-50%. Best results were got with 30 Vol-% ceramic, 4 mm of preform height and 2.5% silicon share in the cast iron. In spite of vacuum support, none of preforms could be filled completely. At the same time, iron silicide reaction products were determined at the interface of ceramic and metal, which react negatively on the properties parts. The structure of metal matrix contains exclusively ductile iron.
For such preforms in the wear-resistant composites, with reference to their dimensions, the small dimensions are not sufficient for good wear-resistance, because the hard parts of components wear out too fast. Besides, the results of infiltration are not sufficient.
Further, a method is known for spontaneous infiltration of SiC-preforms with FeSi-FeSi3 and FeSi-melting (Pan. Y et al: Materials and Engineering A 359 (2003), 343-349). SiC-powder of medium grain size 1.6 µm and 0.5 µm are used as raw material. The preforms are being produced by pressing and have a percentage density between 50 and 55%. The infiltration takes place in a furnace at 16000C, under flowing argon. Filling of 96.5% of theoretic density of composite materials could be achieved. Disadvantage in this method is the time consuming process, which must be realized under argon atmosphere and hence is expensive.

Nakae, H., et al: Int. J of Metal Casting/Spring 11 have described the spontaneous infiltration burnt at 7000C, water glass-bonded SiC-preforms with AI-Si-Mg-melting by adding iron oxide in the sodium silicate binders. SiC-powder was used with 420 µm of medium corn size, wherein even mixtures of various corn sizes in the preforms and the sandwich were tested, to increase the infiltration. The preforms were preheated at 9000C, rinsed with argon, so that no more air was in the pores of preform and subsequently immersed into the aluminium melt for 5 minutes, under protective glass (again argon). Whether a spontaneous infiltration can take place, depends on various factors, like the moisture, the thickness of oxide layer on the melt, arising reaction gases and so on. Often, only a partial infiltration was achieved. Due to time consuming methods in the production of composite materials under protective gases and insufficient reproduction and use of aluminium alloy this process is not practicable.
A spontaneous infiltration of SiC preforms with hastelloy melt (Ni base-alloy) is described by Qian, Q et al: J of Alloys and Compounds 639 (2015) 330-335. Titan are added as wetting additive and as reaction barrier of ceramic and metal, aluminium oxide as raw material. The SiC is used with a particle size of 10 µm and the preforms are filled under argon atmosphere at 14500C, with 1.5 times of hastelloy. The SiC of preform dissolves without aluminium oxide-coating in the infiltration and forms new phase, which is limited by the coating, but is not prevented entirely. A complete infiltration of preform can be excluded, because the share of metal compared to preform size is less.

Disadvantages on this method are the numerous reactions, which must execute everything, in order to reach parts to be infiltrated. On the whole this infiltration method is difficult to control and the reactions require relatively longer time.
Further, it is known that cast iron material with lamellar division and shape of graphite fins possess very unfavourable mechanical properties and hence cannot be used for many wearing applications. To avoid the lamellar graphite secretions and for the formation of special structure the cast iron is injected previously or during the casting with additives. For e. g grey caste iron with iron silicides FeSi (40-80% Si) and elements like Mn, Zn, Ba, AI, Bi and rare earths are injected previously or during the casting, in order to achieve an aimed secretion of graphite. Also, metallurgic SiC is added to obtain special solidification form of ferritic structure. (Knots W.: Casting review 57 (2010) volume 11/12 VDG-leaflets: Injection of cast iron melt, SZ 10th March 1989). The injection can be done in powder form as addition of compact bodies, as wires or as liquid additions, as one or multiple injections at various processing periods. The additives are not in their original shape in casting, after completion, but have dissolved or changed over.
To conclude that the well-known parts made of cast iron composites with hard material or cast iron based alloy hard material –composites can be produced for applications and exist, in which high wear resistance is necessary, yet not sufficiently fast, cost favourable and with sufficiently higher wear-resistance.
The task of existing invention consists in the specification of composite materials, which show very high wear resistance and in the specification of simple and cost favourable methods for their production.

The task is solved by the invention specified in the claims. Advantageous designs are subject of sub-claims.
The invention related composite materials with very high wear resistance consist of cast iron based alloy stored at least in area by area of hard particles, wherein the hard particles are surrounded at least partially by a bonding phase and exist in the iron based alloy secretions of carbon, wherein fin shaped or lamellar secretions of carbon, exist in the area of hard particles and/or of binding phase, around the hard particle in a maximum distance from the surface of hard particles by 10 mm.
Shows an advantage that only areas of composite materials, hard particle and at least a binding phase and a fin shaped or lamellar secretions of carbon are exposed partially to high wearing.
Likewise, an advantage shows that the cast iron based alloy has a content of 1.5 to 6.67 Ma.-% and can show shares of Mn, Cr, Ni and/or Si.
Further an advantage shows the cast iron based alloy the fin shaped or lamellar secretions circular and/or vermicular secretions of carbon and/or carbon exist bonded as cementite or as carbide.
Advantages are particles made of metal carbides and/or metal nitrides and/or metal oxides existing as hard particles and also particles made of cubic boron nitride, titanium nitride, silicon nitride, silicon carbide, boron carbide, wolfram carbide, titanium carbide, aluminium oxide and/or zirconium oxide.

Further advantage is, if a non-metallic binding phase is formed of aluminium oxide, zirconium oxide, titanium oxide, silicon oxide, chromium oxide, silicon carbide, boron carbide and/or their mixtures and/or their compounds.
Likewise, it is advantageous, if the metallic binding phase is formed of metals, from mixtures or compounds/alloys of cobalt, nickel, nickel-chromium and/or iron.
Even it is advantageous, if the fin shaped or lamellar secretions of carbon is arranged in the case of iron based alloy, at least in the interface between iron based alloy and hard particle and/or between iron based alloy and binding phase in direct contact with the hard particle and/or arranged up to maximum 10 mm away from the hard particles and/or arranged in the areas of hard particle and/or of binding phase homogeneously distributed.
It is advantageous, if the fin shaped or lamellar secretions of carbon exist arranged in the cast iron based alloy, in the area of interface between iron based alloy and hard particle and/or between iron based alloy and binding phase, at least predominantly in an angle of 45 to 900 to the respective interface.
Further it is advantageous, if the share on hard particle and binding phase of 20-60 Vol% are stored in the area, in the hard particle at least area-wise in the case iron based alloy.
In the invention related method for the production of composite materials, with very high wear resistance hard particles with at least a temporary binder and materials

are processed for the production of binding phase, to a porous network type green body, subsequently the green body is subjected to temperature treatment for sintering or the green body is brought in a cast shape and subjected to preheating and after sintering or preheating the green body, at least the cavities occurred in the porous network type of sinter body or preheated green body is filled with a liquid iron based alloy and the composite material is cooled.
Advantages are hard material particles made of metal carbides, and or metal nitrides and/or metal oxides, and also particles from boron nitride, titanium nitride, silicon nitride, silicon carbide, boron carbide, wolfram carbide, titanium carbide, aluminium oxide and/or zirconium oxide are used.
Likewise, advantages are materials for the production of metallic binding phase metals, mixture or compounds/alloys of cobalt, nickel, nickel-chrome and/or iron are used.
It is also advantageous, if a quantity of material is used for the production of binding phase, with which the hard particles are covered partially and are connected with each other to a network type of green body.
Further, it is advantageous, if a porous network type of green body is produced, which shows a mechanical strength of three point bending test or at least a mechanical strength, in which the following procedural steps can be realized without partial or complete destruction of green body.

Likewise it is advantageous, if a porous network type of sinter body is produced, which consists of hard particles for the production of binding phase, connected to each other by means of a material.
Also, it is advantageous, if the cavities in the sinter body and/or of green body heated in the casting mould, are filled with liquid cast iron, at least partially and as far as possible completely.
For the first time, composite materials are specified, which show very high wear resistance and can be produced simply and cost favourably.
This is achieved by composite material with very high wear resistance, which consists of a cast iron based alloy, stored in the area of hard particles.
The area-wise storage of hard particle is done within the cast iron based alloy and within a component or with shares of invention related composite material, in particular in the area which wear out highly, during their use.
In these areas a greater number of hard particles is desired and exist in the cast iron based alloy.
The iron based alloy of composite material shows a carbon content of 1.5 to 6.67 Ma.-% and or share of Mn, Cr, Ni and/or Si and shows fin shaped or lamellar secretion of carbon existing in the area of hard particle, outside of hard particle (below only fin shaped or lamellar is mentioned) circular and/or vermicular secretions of carbon content and/or the carbon content can exist, bound as materials of such cast iron based alloy are EN-GJS (cast iron with ductile iron) EN 15 63), GJV (cast

iron with vermicular graphite, EN 16079), White cast iron (with appr. 3% C and 12-28% Cr: for e. g G-X260 Ni Cr 4 2 Nihard 2) to G-X 300 Cr Ni Si 9 5 2 (Ni-Hard 4) DIN 1695) Electro manganese- hard cast (G-X 120 Mn 13) to G-X 120 Mn Cr 132).
Relating to fin shaped or lamellar secretions of carbon it should be understood that as part of invention there appears basically in the shapes I and II, according to DIN EN ISO 945-1:2010-09 and can exist in the arrangements A and B.
However, it is advantageous as per invention if the fin shaped or lamellar secretions of carbon exist in the cast iron based alloy, in the area of interface between iron based alloy and hard particle and/or between iron based alloy and binding phase, at least predominantly in the shape 1, in an angle of 45 to 900 for respective interface.
Particles can exist as hard material made of metal carbides and/or metal nitrides and/or metal oxides, as particles made of cubic boron nitride, titanium nitride, silicon nitride, silicon carbide, boron carbide, wolfram carbide, chromium carbide, titanium carbide, aluminium oxide, titanium oxide and/or zirconium oxide or their mixtures or compounds, for e. g AI2O3-ZrO2, TiCN, SiC-B4C.
Hard materials are characterized by their hardness. They are classified differently, wherein in metallic types like carbide boride, nitride and silicide and non-metal compounds like diamond, corundum, silicon carbide and nitride and boron carbide is differentiated (Kiefer-Benesovsky, hard material, Springer Verlag GmbH, Vienna 1963). Often they are further processed with metallic binding phases, in form of hard metals or using ceramic technologies.

Materials should be understood as per invention under hard materials, which show Vicker’s hardness of >=1300 HV10, preferably by >= 2000 HV10.
As per invention hard particles come into use, which are not hard metals. Hard metals are metal-matric-composites, in which hard material exist in small particle, held together by a matrix made of metal. Hard metals are produced by grinding and mixing original powder by moulding and subsequently sintering under pressure, so that a compressed material is got (Wikipedia, catch word “hard metal”).
The hard particle existing as per invention in the cast iron based alloy are thereby surrounded, at least by a binding phase. Thereby it is about a non-metallic or a metallic binding phase.
The hard particle shows a grain size between 1 and 10 mm, preferably in a narrow grain size distribution. The hard material can be built up as monocrystalline or as polycrystalline and also consists of mixtures and /or compounds of above mentioned material.
The non-metallic binding phase can be formed of mixtures or compounds from aluminium oxide, zirconium oxide, titanium oxide, chromium oxide, silicon oxide, silicon carbide, boron carbide. Thereby, the non-metallic binding phase can contain not only amorphous but also crystalline components, whereby the share of crystalline components contributes between 20 and 80% of non-metallic binding phase. Amorphous components contain less additives of alkaline- and/or alkaline-earth elements and/or other well-known glass former like boron.

The metallic binding phase can be formed from metals, mixtures or compounds/ alloys of cobalt, nickel, nickel-chromium and/or iron.
For the production of porous network type green body, the hard particles are bound partially each other using the binding phase. So that hard particle form a network type structure with the binding phase, which shows sufficient mechanical stability for handling in the technical production process. The special solution existing as per invention is that the hard particle existing with a temporary binder and the materials for the production of binding phase are processed for a porous network type green body.
This green body shows open pours, which exist between the hard particles connected by a bar from the materials for the production of binding phase.
This green body can be sintered, whereby the open celled porous structure of network survive during the sintering. It is also possible that the green body is brought into a cast mould for the production of composite material and is subjected to preheating. Thereby, the sintering of green body is done quasi.
In any case the porous network type structure of green body or sinter body survives and the existing cavities arising on porous network type of sinter body or preheated green body in shape of open pours or network, are subsequently filled with liquid iron based alloy and the invention related composite material exists after cooling.
Preferably 2 to 40 Vol-% still 5 to 20 Vol-% binding phase, with regard to the volume contain the hard particles, in the invention related composite material.

In the invention related composite materials, hard particles can be stored in the area, in which preferably the share of hard particles and binding phase amounts to 20-60 Vol-% in the cast iron based alloy.
Further, in the technical contribution secretions of carbon exist in the cast iron based alloy, whereby fin shaped secretions of carbon exist exclusively in the area of hard particle and/or of binding phase, around the hard particle, in a maximum distance from the surface of hard particle by 10 mm.
Besides, lamellar also star shaped secretions of carbon can exist, in the area of hard particle and/ or of binding phase.
Especially it is advantageous for the invention related solution, if the lamellar shaped secretions of carbon exist in the cast iron based alloy, in the area of hard particles and/or of binding phase, at least predominantly arranged in an angle of 45 to 900 for the interface between iron based alloy and binding phase and hard particles and/or between iron based alloy and binding phase.
Thereby a brush shaped structure of lamellar secretion of carbon with reference to the interfaces, exist between iron based alloy and hard particle and/or between iron based alloy and binding phase. The lamellar secretion of carbon can be isolated, arranged in group or near each other or in star shape. Preferably the lamellar secretions are made of graphite.

With the invention related composites, there exist quasi an impregnated composite, in which possibly all cavities, pores and cracks in and around the hard particle and the binding phase are filled by the cast iron based alloy. The cast iron based alloy can thereby be so-called cast iron with ductile iron or vermicular graphite, white cast iron (Nihard, chromium hard cast) or manganese hard cast.
In the invention related composite material and/or in a part with at least areas of composite material, there exists areas without the lamellar secretions of carbon. However, it is technical contributions, where there is no invention related composite material existing in a part, no lamellar secretions of carbon and may not exist.
In the areas of invention related composite material, in which hard particles and/or binding phase exist, always at least lamellar secretions of carbon in the cast iron based alloy, however only exclusively in the area of hard particle and/or of binding phase around the hard particle, in a maximum distance from the surface of hard particle by 10 mm.
For the invention related solution it is of special importance that in the production of invention related composite material, it does not dissolve the hard particle completely and the binding phase or come to a chemical change or a conversion, but the hard particle survive essentially or predominantly, in their original form and composition and thus can serve in the fin shaped secretions of carbon as quasi growth seeds.

Hence, the greater number of lamellar secretion arrangement is to be seen always, in the surface area of hard particle and/or of interface of binding phase. The dissolution of hard particle and of binding phase is avoided by an adjustment of casting conditions, in particular casting temperature, which can be determined, simply by an expert through few tests.
Outside of areas described in the invention around the hard particle, there are no fin shaped secretions of carbon, which can be achieved by the well-known processing steps for the production of lamellar-free cast iron, like for e. g by adding alloy components, desulphurisation and addition of special injection materials.
The invention related composite material are produced with very high wear resistance by a method, in which hard particle and materials are processed, for the production of binding phase, with at least temporary binder to a porous network type green body. The temporary binder serves in the production of green body and does not form the binding phase.
For that hard particles are mixed with the materials for the production of binding phase, which are commercially available, whereby hard particles are added, predominantly. Thereby hard particles are obtained, which at least are covered and/or wrapped partially by the materials for the production of metallic or non-metallic binding phase.
Preferably, one such quantity can be used on binding phase, which for e. g up to 98 Vol-% of hard particle are wrapped completely.

Particles made of metal carbides and/or metal nitrides and/or metal oxides, made of cubic boron nitride, titanium nitride, silicon nitride, silicon carbide, boron carbide, wolfram carbide, chromium carbide, titanium carbide, aluminium oxide, titanium oxide and/or zirconium oxide or their mixture or compounds, for AIO3-ZrO2, TiCN, SiC-B4C can exist as hard particle.
The hard materials show Vicker’s hardness of >=1300 HV10, preferably by >= 2000 HV10.
The used hard particle shows a grain size between 1 and 10 mm, preferably in a narrow grain size distribution. The used hard material can be built up as monocrystalline or as polycrystalline and also consists of mixtures and /or compounds of above mentioned material.
The hard particle in the cast iron based alloy are thereby at least, partially surrounded by a binding phase. Thereby it deals on a non-metallic or a metallic binding phase.
Aluminium oxide, zirconium oxide, titanium oxide, silicon oxide, aluminium hydroxide, calcium carbonate, silicon carbide, boron carbide and/or mixtures and/or compounds of it can be used, as materials for the production of non-metallic binding phase.
Metals, mixtures or compounds/alloys of cobalt, nickel, nickel-chromium and/or iron are used as materials for the production of metallic binding phase.

As temporary binder, which hold the hard particle together and the materials for the production of binding phase, in the green body prior to the sintering known binders are used for the production of hard materials like polyvinyl alcohol, polyacrylate, polysaccharides in a weight share of 0.5-5.0 vol%, with reference to hard material/binding phase mixture.
From the mixture of hard particles, a porous network type green body is produced using a well- known shaping method, the materials for the production of binding phase and at least for a temporary binder, like slip casting, pressing, pounding, extrusion and subsequently drying step up to 2000C on air.
To remove the temporary binder and to achieve strength of green body for further processing at higher temperatures, a thermal treatment is done on one side of green body, at sinter temperatures up to 21000C on air or inert gas or on vacuum, at which the binding phase is formed around the hard particle and the network type porous sinter body.
On the other side, the green body can also be brought into a mould, in which the iron based alloy is casted. In this case, a solidification and removal of temporary binder is done, during the necessary heating of mould is realized and the final production of network type of porous sinter body during the casting process.
The porous network type of green body thus produced shows preferably a mechanical strength of 0.2-1 Mpa (three-point bending test), at least such mechanical strength, at which the following process step can be realized without partial or complete destruction of green body.

The porosity of sinter body can be influenced by controlling the storage of hard particles, in the binding phase. The porous network type of sinter body thus produced consist of hard particles connected with each other by means of binding phase.
The porous network type of sinter body thus produced can further show a structural built up, the cavities without hard particles and shows binding phase. For e. g holes, implementation, cavities are brought into the sinter body or are created during the production of green body, which subsequently are filled, only with cast iron based alloy.
After the production of sinter body or during the preheating of mould, green bodies are strengthened and then the cavities are filled with liquid iron based alloy and the produced composite materials are cooled.
The iron based alloy can be brought in by means of gravity casting.
Special pressure supported casing methods are possible, but not necessary.
The cavities of sinter body or of strengthened green body are filled with liquid iron based alloy, at least partially, possibly complete, while preheating the mould. Thereby, all cavities, pores, cracks of composite materials are filled completely.

Special advantage of it is, if silicon carbide particles are used as hard material. So far silicon carbide particles were not used as hard material for the cast iron- hard material compound, because the experts assume that silicon carbide will dissolve during the production of composite material or will react heavily with the cast iron.
The non-metallic binder used for the production of binding phase consists of silicon oxide, preferably with stored particles from aluminium oxide or instead of silicon oxide from one of reaction formation, made of aluminium hydroxide, clay and liquid medium and as cast iron white cast iron, which is filled in the sinter body or in the solidified green body while preheating the cast mould.
The production of green body is done, preferably by mixing the hard particle with the materials, for the production of binding phase and the temporary binder and by slip casting the mixture, for a green body at ambient temperature. The green body is warm heated, so that it is processed after sintering for a network type porous sinter body, which is inserted subsequently into the cast mould and then is filled with liquid iron based alloy. But it is also possible to insert the unsintered green body into the cast mould, to heat the cast mould and then to fill in the liquid iron based alloy. On both ways, the production of invention related composite material is realizable.
During the production of composite material, the temporary binder is removed, while sintering or pre-warming the cast mould. While sintering it results in formation of binding phase. The binding phase in the green body forms itself in the cast mould, while casting.

The invention related production method is of special importance for the composite material that as far as a porous network type green body made of hard particles exist, with a temporary binder and the materials are used for the production of binding phase, which shows open pores and bar. This porous network type structure of green-/sinter body is then filled with a liquid iron based alloy.
The sinter body or green body produced as per invention can be in various sizes and shapes, adapted in the cast mould, which are then filled with cast iron based alloy. For that the green body, preferably the sinter body are warmed in the cast mould, for e. g at 400- 8000C and then filled with the liquid iron based alloy. After cooling the moulded part, it is removed from the cast mould. The moulded part contains the invention related composite material.
For the measurement of properties a wear part is pulled up, which enables statement on material behaviour, how they appear in sliding guide or in crushing process with compressive stress and relative movement. The test stand consists of a rotating workbench with a circumference of 1.153 m, on which a ring test probe made of nihard is stretched. Besides there is a laterally guided test probe, made of composite material, by which the precise dimension is determined, before beginning the test. In the gap between the ring test probe and the test body an abrasive intermediate is given, in the form of silica sand with 0.1- 0.5 mm of medium particle size. By rotating the work bench with a circumferential speed of 0.5 m/s the silica sand reaches between ring test probe and test body. The test body is pressed by using weight with a surface pressure of 0.5 Mpa.

By determining test distance after 20-30 km, the test body is removed and by using the dimension of specific wear erosion in mg/km. A conventional nihard material shows a wear erosion of average 225 mg/km.
With the invention related composite materials, the wear erosion could be reduced averagely by 20-40 mg/km, which corresponds to 10- times wear reduction.
This wear reduction is caused by the lubrication effect of lamellar carbon precipitation, above all around the hard particles.
Hence, a distinct reduction of wear is achieved on invention related cast iron-hard material-composites, which results in considerable increase of life time of parts with the composite materials.
It is surprising that usually a cast iron free from carbon lamella is used for wear application, while the invention related carbon lamellas in the area of hard materials, result in an improvement of wear behaviour of cast iron, apart from free of lamella.
Another advantage is the high flexibility in the production of shapes, by the possibility during the production of green body, in particular with reference to their geometric dimensions and formations, also with reference to variability of arrangement of hard materials and their number and type in the composite material.
Below the invention is elucidated in detail, on two execution examples.

Example 1
A green body is produced, for the production of composite material.
To become 500 mg silicon carbide powder with a FEPA-grain size F8 with a medium grain size of 2.5 mm
+ 25 g of silicate salt water with a particle size of 35 nm in a concentration of 50% and
+45g of aluminium oxide powder with a medium particle size of 5 µm and a 96% purity and
+ 5g of aqueous polymeric dispersion in a concentration of 60% added as temporary binder.
The dispersion is mixed in a container with a diameter of 150 mm with a propeller stirrer of diameter 50 mm, at speed of 300 U/min for five minutes.
Subsequently, this mixture is filled in a rectangular shaped mass 100x100x40 mm, in which 8 shapes are arranged for the production of cylindrical rods with a diameter of 15 mm equally distributed. Finally, the mixture is dried in the shape, in a drying cabinet at 1500C, for two hours, taken from the shape. The green bodies thus produced are burnt on air, at 13000C with a retention time of one hour.
The sinter bodies thus produced are inserted into a cast mould, lined with refractory bricks, fixed with screws via the holes arising through the rods and preheated commonly with the shape, in an oven at 6000C. Subsequently the cast mould is

removed from the oven and the sinter body is filled with a melt from white cast iron EN-GJN-HV600, with a content of approx. 3.2 Ma-%. Thereby, all pores in the sinter body is filled and the invention related composite material exists with the penetrated structure. After cooling the composite material is removed and can be further processed.
Subsequently, from the composite material a sample of size 15x15x15 is extracted, from the area of composite, with and without ceramic components. These are embedded in resin and a sanding is prepared for the judgement of structure, as well as tested radiographic on its composition. The original SiC-particles are determined, in the sample from the composite material, with ceramic components in the subsequent microscopic test, which are partially surrounded by ceramic binding phase made of AI2O3 and SiO2, with a crystalline share of approx. 70% (Mullite) and reaction products from iron silicide. Subsequently it is that the cast iron has filled all cavities between the ceramic. In the structure of cast iron graphite lamella are to be identifiable up to a distance of approx. 8 mm is , away from the hard particles, which has increased partially, from the interface between non-metallic binding phase and cast iron and from the interface between SiC-particles and cast iron vertical or in other angles.
The share of hard particles and binding phase in the area of composite material with ceramic components, comes to 40 Vol-%.
In the sample none with cast iron and without ceramic components or only few globular graphite secretions are to be seen.

Further again, two sample bodies of dimension 25x60 mm are prepared from the composite material, from the area of composite of cast iron and tested in the described wear test. Thereby, the sample has only from cast iron a wear rate of 110 mg/kg and the sample of composite materials from cast iron, with ceramic components a wear rate of 25 mg/kg, which corresponds to a distinctly reduced wear.
Sample 2:
Additionally a green body is produced for the production of composite material.
For that, to 300 mg corundum powder with a FEPA-graining F8 with a medium grain size of 2.5 mm
+ 15 g of anionic silicate salt water with a particle size of 35 nm in a concentration of 50% and
+ 27g of silicon carbide powder with a medium particle size with a FEPA-graining F 1000 with a medium grain size of 4.5 µm and
+ 3g of aqueous polymeric dispersion in a concentration of 60%, are added as temporary binder.
The dispersion is mixed in a container with a diameter of 150 mm by a propeller stirrer of diameter 50 mm, at speed of 300 U/min for five minutes.

This mixture is subsequently filled in a rectangular shape of dimension 100x60x30 mm, in which 4 shapes are arranged for cylindrical rods, with a diameter of 12 mm in a distance of 10 mm from the corners. The mixture is subsequently dried, in a drying cabinet in the form, at 1500C for two hours and removed from the form.
The green body thus produced are inserted into cast mould lined with cordierite bricks, fixing with brackets using the holes arising through the rods and preheated together with the form, in an oven at 8000C.
Thereby a solidified green body is got, in which the temporary binder is removed, however no binding phase is formed.
Subsequently, the cast mould is removed from the oven and filled with a melt from cast iron with ductile iron EN-GJS-500 (C-content approx. 3.8 Ma.-%). Thereby all pores of solidified green bodies got filled up and the invention related composite material exists with the penetrated structure. After cooling the composite material is removed and can be processed further.
Subsequently, a sample of size 15x15x15 mm is taken from the composite material, from the area of bonding, with and without ceramic components. These are embedded in resin and a sanding is prepared for the judgement of structure, as well as for radiographic test. In the sample from the composite material, with ceramic components, the original corundum particles are determined in the subsequent microscopic test, which are surrounded partially by ceramic binding phase. The ceramic binding phase consists of SiO2 and SiC, whereby of it approx. 60% are crystalline, on the whole. The share of hard particles and binding phase in the area

of composite material, with ceramic component, comes to approx. 50 Vol%. The cast iron is in it, which has filled all cavities between the ceramic. In the structure of cast iron graphite lamellas are identifiable, which are increased partly from the interface between binding phase and cast iron vertical or in other angles.
In the sample, the typical globular graphite secretions are to be seen, with only cast iron with ductile iron, without ceramic components.
Further, two test bodies of dimension 25x60 mm are prepared from the composite material, from the area of bonding, by cast iron with and without ceramic components and tested in the described wear test. Thereby, the sample made of cast iron has a wear rate of 250 mg/kg and the sample of composite material made of cast iron ceramic components, with a wear rate of 80 mg/kg, which corresponds to distinctly reduced wear.

WE CLAIM:
1. Composite materials with very high wear resistance, which consists of a cast iron based alloy, in which hard particles are stored area by area, wherein the hard particles are surrounded, at least partially by a binding phase and are bonded each other at least partially, using the binding phase and secretions of carbon exist in the iron based alloy, whereby the fin shaped or lamellar secretions of carbon exist, in the area of hard particle and/or of binding phase, around the hard particle in a maximum distance from the surface of hard particle by 10 mm.
2. Composite materials as per claim 1, in which only the areas of composite materials, which are exposed to high wearing, show hard particles and at least partially a binding phase and fin shaped or lamellar secretions of carbon.
3. Composite materials as per claim 1, in which the cast iron based alloy shows a carbon content of 1.5 to 6.67 Ma.-% and can show shares of Mn, Cr, Ni and/or Si.
4. Composite materials as per claim 1, in which the coast iron based alloy shows, in addition to the fin shaped or lamellar secretions circular and/or vermicular secretions of carbon and/or carbon exists bonded as cementite and/or as carbide.

5. Composite material as per claim 1, in which particles made of metal carbides and/or metal nitrides and/or metal oxides, preferably particles from cubic boron nitride, titanium nitride, silicon nitride, silicon carbide, boron carbide, wolfram carbide, titanium carbide, aluminium oxide and/or zirconium oxide exist as hard particle.
6. Composite material as per claim 1, in which the binding phase shows an amorphous structure with crystalline share, between 20 and 80%.
7. Composite material as per claim 1, in which a non-metallic binding phase is formed from aluminium oxide, zirconium oxide, titanium oxide, silicon oxide, chromium oxide, silicon carbide, boron carbide and/or their mixtures and/or their compounds.
8. Composite material as per claim 1, in which the metallic binding phase is formed from metals, from mixtures or compounds/alloys of cobalt, nickel, nickel-chromium and/or iron.
9. Composite material as per claim 1, in which the fin shaped or lamellar secretions of carbon, are arranged in the cast iron based alloy, at least in the area of interface between iron based alloy and hard particle and/or between iron based alloy and binding phase in direct contact with the hard particles and/or are arranged up to maximum 10 mm away from the hard particles, and/or arranged in the area of hard particle and/or of binding phase homogeneously distributed.

10. Composite material as per claim 1, in which the fin shaped or lamellar secretions of carbon in the cast iron based alloy, exist in the area of interface between iron based alloy and hard particle and/or between iron based alloy and binding phase, at least predominantly in angle of 45 to 900 to the respective interface.
11. Composite material as per claim 1, in which hard particles are stored in the area, in which at least area by area in the cast iron based alloy, the share of hard particle and binding phase comes to 20-60 Vol%.
12. Method for the production of composite materials with very high wear resistance, in which hard particles are processed, with at least a temporary binder and materials for the production of binding phase to a porous network type green body, subsequently the green body is subjected to a temperature treatment for sintering, or the green body is brought into a cast mould and is subjected to a preheating, and after sintering or heating the green body, at least the cavities of network type pores arising in the sinter body or preheated green body is filled with liquid iron based alloy and the composite material is cooled.
13. Method as per claim 12, in which particles made of metal carbides and/or metal nitrides and/or metal oxides, preferably particles from boron nitride, titanium nitride, silicon nitride, silicon carbide, boron carbide, wolfram carbide, titanium carbide, aluminium oxide and/or zirconium oxide, are used as hard particles.

14. Method as per claim 12, in which aluminium oxide, zirconium oxide, titanium oxide, silicon oxide, aluminium hydroxide, potassium carbonate, silicon carbide, boron carbide and/or mixtures and/or compounds of it are used, as materials for the production of non-metallic binding phase.
15. Method as per claim 12, in which metals, mixtures or compounds/alloys of cobalt, nickel, nickel-chromium and/or iron are used, as materials for the production of metallic binding phase.
16. Method as per claim 12, in which a number of material is used for the production of binding phase, with which the hard particle is covered partially and are bounded with each other to a network type green body.
17. Method as per claim 12, in which a porous network type green body is produced, which shows a mechanical strength of 0.2-1 Mpa in the three point bending test, or shows at least such a mechanical strength, in which the following procedural steps can be realized without partial or complete destruction of green body.
18. Method as per claim 12, in which a porous network type sinter body is produced, which consists of hard particles, bonded each other by means of materials, for the production of binding phase.

19. Method as per claim 12, in which the cavities of sinter body and/or of green body preheated in the cast mould, are filled, partially as far as possible completely with liquid cast iron.