DESC:AIR INTAKE OUTER CASING AND MANUFACTURING METHOD FOR THE SAME

Technical Field
[001] The present invention relates to additive manufacturing of aerospace parts. Particularly, the present invention relates Air intake outer casing and a method of manufacturing air intake outer casing in jet engine compressor section.

Background of the Invention
[002] Air intake outer casing in an aeroplane engine compressor section directs airflow onto a compressor wheel. Traditionally, the air intake outer casing is manufactured by spinning operation followed by a machining operation. However, the traditional method for manufacturing of the air intake outer casing was a challenging task owing to the round shape, thin wall thickness and integral features like holes and slots of the air intake outer casing. Moreover, diameter and depth of the traditionally manufactured air intake outer casing were limited by the size of equipment used for manufacturing. Additionally, cost of manufacturing using manual traditional mechanism incurred high labour costs. Thus, the method for manufacturing of air intake outer casing has been an active area of research.
[003] Thus, there is a need for a system and a method that alleviates the problems associated with the current manufacturing methods.

Objects of the invention
[004] It is an object of the present invention to provide an Air intake outer casing.

[005] It is another object of the present invention to provide a manufacturing method for an Air intake outer casing through additive manufacturing.

[006] Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.

Brief description of accompanying drawings
[007] The invention will now be described in relation to the accompanying drawings, in which:
[008] Figure 1 illustrates air intake outer casing printed in additive manufacturing.
[009] Figure 2 shows the flowchart of an invented process for air intake outer casing manufacturing.

Summary of the invention
[0010] In accordance with an embodiment of the present invention, additive manufacturing is used to manufacture air intake outer casing. In an example, the air intake outer casings manufactured in a single print by the additive manufacturing. Further, the additive manufacturing based on the present invention is a computerized mechanism for manufacturing the air intake outer casing.

[0011] In one embodiment, the process for the manufacturing air intake outer casing comprises the following steps:
a) providing metal powder as a raw material wherein the metal powder is selected from a group consisting of Nickel based alloy, Titanium alloys, Aluminum and Steel alloy;
b) spreading said powder layer by layer on a predetermined platform;
c) selectively fusing said powder using at least one energy source selected from the group consisting of laser, electron beam and the like to perform printing operation to obtain an air intake outer casing;
d) transferring said air intake outer casing with build platform to a furnace in order to heat said air intake outer casing with build platform at a predetermined temperature followed by cooling to room temperature to obtain heat processed air intake outer casing with build platform; and
e) subjecting said heat processed air intake outer casing with build platform to wire cutting operation to separate the air intake outer casing from the build platform followed by shot blasting to generate compressive residual stresses on the surfaces of the air intake outer casing and buffing operation to obtain the air intake outer casing with pre-determined surface finish.

[0012] In another embodiment, there is provided a process for manufacturing an air intake outer casing, said process comprising the following steps:
a. generating a CAD model using computer aided design;
b. converting the model into a Surface Tesselation Language / Standard Triangulation Language file (STL);
c. generating additive manufacturing program by importing STL file into a MAGICS MATERIALISE software adapted to define part orientation and generate support;
d. transferring the STL file to a slicer software for slicing;
e. importing the file in an EOSPRINT software adapted for assigning the build parameters which are further are optimized for CAD data;
f. designing parameters selected from laser power, scanning speed, hatch distance and layer thickness;
g. exporting the file to the 3D printing machine for producing the air intake outer casing.
h. spreading metal powder layer by layer on a predetermined platform;
i. selectively fusing said metal powder using at least one energy source at predetermined conditions to perform a printing operation to obtain the air intake outer casing;
j. heat treating said air intake outer casing with build platform in a furnace at a predetermined temperature followed by cooling to room temperature to obtain heat treated air intake outer casing with build platform;
k. subjecting said treated air intake outer casing with build platform to wire cutting operation to separate the air intake outer casing from the build platform, followed by shot blasting to generate compressive residual stresses on the surfaces of the air intake outer casing, and buffing operation to achieve the air intake outer casing with pre-determined surface finish.
a. In another aspect there is provided an air intake outer casing (100) obtained by the process as described hereinabove. The Fig. 1 illustrates an air intake outer casing (100) in which the outer casing is shown by numeral 12 and the casing features are shown by numeral 14.
[0013] In one embodiment, the air intake outer casing is made of Inconel material and said air intake outer casing exhibits a tensile strength of >1241 MPa, a yield strength of about 1150 MPa and a hardness of about 47 HRC. In another embodiment, the air intake outer casing is made of aluminium material and said air intake outer casing exhibits a yield strength of about 210MPa and a hardness of about 107 HV. In another embodiment, the air intake outer casing is made of steel material and said air intake outer casing exhibits a yield strength of about 470MPa and a hardness of about 32 HRC. In still another embodiment, the air intake outer casing is made of titanium material and said air intake outer casing exhibits a yield strength of about 1070 MPa and a hardness of about 39 HRC.

Description of the invention
[0014] In accordance with an embodiment of the present invention, additive manufacturing is used to manufacture air intake outer casing. The additive manufacturing, as disclosed in the present invention, is a manufacturing method in which air intake outer casing and its integrated casing features are produced.

[0015] In accordance with an example of the present invention, the air intake outer casing is made by using a digital model and layer by layer material build-up approach. The digital and computer-implemented method of manufacturing of the present subject matter is tool-less.

[0016] In an additional implementation, the present invention relates to the manufacturing of an air intake outer casing for jet engines using the selective laser sintering process.

[0017] The present invention describes the elimination of spinning metal forming and machining processes to make the air intake casing. It also eliminates the problem of distortion and run out of the casing. Increased productivity and reduced cost of production are achieved by the reducing number of steps in manufacturing processes. The additive manufacturing approach eliminates the spinning metal forming processes in air intake outer casing manufacturing. Additionally, the present invention produces uniform/integral air intake outer casing with other features like holes and slots in a short time with high precision.

[0018] In one embodiment, the process comprises the following steps:
• providing metal powder as a raw material wherein the metal powder is selected from a group consisting of Nickel based alloy, Titanium alloys, Aluminum and Steel alloy;
• spreading said powder layer by layer on a predetermined platform;
• selectively fusing said powder using at least one energy source selected from the group consisting of laser, electron beam and the like to perform printing operation to obtain an air intake outer casing;
• transferring said air intake outer casing with build platform to a furnace in order to heat said air intake outer casing with build platform at a predetermined temperature to obtain heat processed air intake outer casing with build platform; and
• subjecting said heat processed air intake outer casing with build platform to wire cutting operation followed by shot blasting and Micro Machining Process / buffing operation which is further followed by the X-ray tomography i.e. NDT (Non-destructive Testing) test to obtain the air intake outer casing on the air intake outer casing.
• According to the present invention several types of supports which can be used during the 3D printing are tried. The type of support to be used is decided based on the quantity of material required for supports, heat dissipation of product to surrounding, geometry of model etc. Different types of supports which are tried include Block type, Line type, Point type, Web Type, Contour type, Gusset type, Volume type and Hybrid Type etc. The support structure with different features like hatching, hatching teeth, fragmentation, borders, border teeth, perforations, gusset borders etc. are experimented.
• Based on the considerations and experimentations, during the manufacturing of the air intake casing, the preferred type of supports used are combination of block support with hatching teeth and perforation type support, volume support and hybrid support.

[0019] Figure 1 illustrates air intake outer casing (with its casing features like slot, steps and holes) printed in additive manufacturing. According to the present invention, the manufacturing process starts with a metal powder as a raw material. The different types of materials (powders) can be used for manufacturing air intake casing which include but are not limited to Nickel based alloys (IN718, IN713C, IN625, etc.), titanium alloy, steel, Aluminium and the like.

[0020] The powder is spread on bed layer by layer and selectively fused by using an energy source like a laser or electron beam. After completion of the print, part with build platform is transferred to the furnace, where heat treatment is conducted and required properties are achieved. The final part is separated from the build platform by using wire cutting operation. The final part is then transferred to shot blasting to generate compressive residual stresses on the surface. Then MMP (micro-machining process) / buffing is carried out on the final part to achieve the required surface finish. Finally, the X-ray tomography i.e. NDT test is conducted on the air intake outer casing for surface crack detection and quality inspection.

[0021] Figure 2 illustrates an air intake outer casing manufacturing process. The air intake outer casing manufacturing process serially includes CAD Model generation, additive manufacturing program generation, Additive Manufacturing or 3D printing, heat treatment, Wire cutting & support removal, shot blasting, Micro Machining Process (MMP)/buffing for Polishing, and NDT.

[0022] In accordance with an implementation, the step of CAD Model generation includes producing a digital model is the first step in the additive manufacturing process. The digital model is produced by using computer-aided design (CAD), refer fig.1. Then this CAD model converted into the stereo lithography / Surface Tesselation Language / Standard Triangulation Language file (STL) which is used by further portions and processes of this invention.

[0023] In accordance with another implementation, the step of Additive Manufacturing program generation includes importing STL files, once an STL file has been generated, into a MAGICS materialise software. In MAGICS, part orientation and support generation takes place. Then STL file sent to the slicer software for slicing. After slicing, the file is imported in EOSPRINT software. In EOSPRINT software, build parameters are assigned and optimized for CAD data. Then after parameters like laser power, scanning speed, hatch distance and layer thickness are defined. Finally, the file is export to the 3D printing machine for final printing.
[0024] In an embodiment, the step of additive manufacturing or 3D printing includes spreading power on the platform layer by layer with a layer thickness ranging from 0.020 mm to 0.080 mm and a laser strip width in the range of 3 to 10 mm. Typically, the overlap between the layers is in the range of 0.10 to 0.15 mm. In one preferred embodiment, the layer has a thickness of 0.02 mm, a laser strip width 5 mm and the overlap between the layers is 0.12 mm.

[0025] In one embodiment, the spreading comprises controlled deposition of the layers of metal powder to form the air intake outer casing. In one embodiment, the spreading comprises depositing layers of a metal powder sequentially one upon the other to form features.

[0026] During this activity, platform temperature is maintained between 80 to 165ºC throughout the process. After spreading, the powder is selectively fused using at least one energy source at predetermined conditions to perform a printing operation to obtain air intake outer casing. Typically, the energy source is selected from the group consisting of laser beam and electron beam. After each layer, the powder is selectively fused by using a laser with power ranging from 80 to 400 watt and with a scanning speed ranging from 800 mm/Sec to 1400 mm/Sec in an Argon environment. In one preferred embodiment, the energy source has a scanning speed of about 1000 mm/second and, has power of 195 watt.
[0027] During this activity, typically, the temperature of the platform is set in the range of 110 to 130ºC preferably at 120ºC.
[0028] In one preferred embodiment, the heat treatment step involves the following steps for Nickel Based Alloy preferably IN718:
[0029] Step A: annealing the air intake outer casing with build platform at a temperature ranging from 900 to 1200°C for a period ranging from 30 minutes to 120 minutes in an inert Argon atmosphere followed by cooling to room temperature. The output of this stage is annealed air intake outer casing with build platform.
[0030] Step B: ageing the air intake outer casing with build platform by holding the part at a temperature ranging from 700 to 800°C for a time period ranging from 5 to 10 hours in an inert Argon atmosphere followed by cooling to a temperature ranging from 625 to 675°C in 1 to 3 hours and holding at a temperature ranging from 625 to 675 °C for 6 to 10 hours in an inert Argon atmosphere. The output of this stage is aged air intake outer casing with build platform.
[0031] Step C: air cooling said air intake outer casing with build platform to room temperature to obtain a heat treated air intake outer casing with build platform.
[0032] In fourth step, the heat treated air intake outer casing with build platform is subjected to wire cutting operation to separate the air intake outer casing from the build platform and thus obtain a separated air intake outer casing.
[0033] In the fifth step, the separated air intake outer casing is subjected to shot blasting to generate compressive residual stresses on the surfaces to obtain a shot blasted air intake outer casing.
[0034] In the sixth step, a buffing operation is performed on the shot blasted air intake outer casing to obtain the air intake outer casing with predetermined surface finish.

[0035] The output of this process is an air intake outer casing with a build platform. The summary of parameters used to produce the air intake outer casing from the material IN 718 (Nickel Based Alloy) in additive manufacturing is mentioned in table 1.
Table 1
Parameters Value
Part (Air Intake Casing)
Layer thickness 0.020 mm to 0.080 mm
Platform temperature 120ºC
Chamber environment Argon
Hatching strip width 3 mm to 9 mm
Skip Layer 0
Scanning speed 800 mm/Sec to 1400 mm/Sec
Laser Power 80 Watt to 400 Watt
Strip Width 3 mm to 9 mm
Strip Overlap 0. 1 mm to 0.15 mm
Supports for Air Intake casing
Layer thickness 0.020 mm to 0.080 mm
Platform temperature 120ºC
Chamber environment Argon
Skip Layer 1
Scanning speed 500 mm/Sec
Laser Power 90 Watt
Beam Offset 0.015
[0036] The summary of parameters used to produce the air intake outer casing from Aluminum, Steel and Titanium alloy in additive manufacturing is mentioned in Table 2:
Table 2
Parameter \Material Aluminum Steel (SS316L) Titanium (Ti6AI4V)
Layer thickness 0.030mm to 0.060mm 0.020mm to 0.060mm 0.030mm to 0.060mm
Platform Temperature 120 to 1650C 80 to 1200C 120 to 1650C
Chamber Environment Argon Argon Argon
Hatching strip width 5 mm to 10 mm 5 mm to 10 mm 5 mm to 10 mm
Scanning speed 800mm/sec to 1400mm/sec 800mm/sec to 1400mm/sec 800mm/sec to 1400mm/sec
Tensile Strength Min 360 MPa Min 540 MPa Min 1200 MPa

[0037] In another embodiment, Nickel based alloy preferably IN718 is used to prepare the air intake casing. Heat treatment is carried out on the air intake outer casing with built platform to achieve the mechanical properties. Firstly, the air intake outer casing with built platform is solution annealed in an inert Argon atmosphere. The air intake outer casing with built platform is solution treated at 1065 °C for one hour in an inert Argon atmosphere, followed by air cooling to room temperature. The second heat treatment is ageing. In this treatment, the air intake outer casing with built platform is held at a 760°C temperature for 10 hours time in an inert Argon atmosphere, after that, it is furnace cooled to 650°C in two hours and then held at 650°C for eight hours in an inert Argon atmosphere. Finally, the casing with built platform is air cooled to the room temperature.

[0038] In one non-limiting illustrative embodiment air intake casing is manufactured by the present method using IN718 material. The mechanical properties achieved after heat treatment are summarised in table 3 (Material used: IN718). The below provided properties and values are illustrative and not considered as limitation to scope of the present invention.
Table 3
Mechanical properties Value
Tensile strength Min 1241 MPa
Yield strength 1150 MPa
Elongation 12 %
Hardness 47 RC

[0039] In another embodiment, Aluminium is used to prepare the air intake casing. A heat treatment is carried out on an air intake casing with built platform to achieve the mechanical properties. Solution annealing is not required. The air intake casing with built platform is aged at 330°C for 2 hours, followed by air cooling.

[0040] In still another embodiment, steel alloy (SS316L) is used to prepare the air intake casing. Annealing heat treatment is carried out on SS316L 3D Printed parts with built platform to achieve the mechanical properties. Heating is carried out at 1066°C for 1.5 hours followed by air cooling.

[0041] In yet another embodiment, Titanium alloy (Ti6Al4V) is used to prepare the air intake casing. The heat treatment is carried out on Ti6Al4V 3D printed parts with built platform to achieve the mechanical properties. Firstly, stress reliving heat treatment with built platform is carried out at 650 °C for 3 hrs. in an inert argon atmosphere, followed by air cooling. To increase ductility and reduce tensile strength, a heat treatment is carried out at 800°C up to 1 to 4 hrs. in an inert argon atmosphere followed by air cooling.

[0042] The mechanical properties of the air intake casings manufactured by the present method using Aluminum, Steel and Titanium materials achieved after heat treatment are summarised in table 4. The below provided properties and values are illustrative and not considered as limitation to scope of the present invention.
Table 4

Mechanical Properties Value
Aluminum Steel (SS316L) Titanium (Ti6Al4V)
Yield strength 210 MPa 470MPa 1070MPa
Elongation 6% 50% 11%
Hardness 107 HV 32 HRC 39 HRC
[0043] In an example, the step of wire cutting & support removal is implemented to separate the heat treated air intake outer casing from the build platform. Next, the support formed during the 3D printing operation is machined off.

[0044] In another example, the step of shot blasting is performed after wire cutting to generate the compressive residual stresses on air intake outer casing surface. The shot blasting is carried out using steel balls of 0.7 mm dia. and ceramic balls of 0.1 mm dia.

[0045] In an implementation, the step for MMP/buffing for polishing is performed to achieve the desired finish. The machining process MMP/buffing may continually reproduce mirror-like finishes with unrivalled aesthetic consistency and technical precision. Additionally, MMP/buffing will reduce friction, extremely low material removal, homogeneity of treatment across entire surface and respect of tolerances.

[0046] Finally, the air intake outer casing is tested for surface quality and cracks by X-Ray tomography, as the step of NDT in accordance with another implementation of the present invention.

[0047] In accordance with another aspect of the present invention there is also provided the air intake casing manufactured by additive method of the present invention, said air intake casing characterized by predetermined structural configuration and pre-determined properties. In one embodiment the structural configuration is illustrated in figure 1 of the accompanying drawing.

[0048] In accordance with still another aspect of the present invention there is a system /assembly for making air intake casing using 3D printing method. The system comprises a printing device and at least one pre-designed support means.

[0049] In accordance with still another aspect of the present invention there is also provided a system for manufacturing air intake outer casing by 3D printing method, said system comprises 3D printing device and support. It is critical to design an optimized support which can be suitable for printing air intake outer casing, as other type of support makes marks on surface of parts. In one embodiment, the support comprises teeth/grooves. The teeth/grooves enable easy removal of supports. Support height is optimised for better heat transfer (heat dissipation) between build platform and job at the time of part building. It also avoids distortion in the part. The amount of support required to build the part is based on the orientation of part. The optimised orientation is selected based on least amount of material required for support generation, minimum laser travel time for generating the support, support free critical areas of the component and height of support that dissipates better heat transfer to build platform from job. Based on above factors for optimized orientation of air intake outer casing, the preferred type of supports used are combination of block support with hatching teeth and perforation type support, volume support and hybrid support and the height of supports is selected from the range of 55 mm to 2 mm.

[0050] While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

,CLAIMS:We Claim:
1. A process for the manufacturing air intake outer casing; said process comprising the following steps:
a. providing metal powder as a raw material wherein the metal powder is selected from a group consisting of Nickel based alloy, Titanium alloys, Aluminum alloy and Steel alloy;
b. providing a 3D printing device
c. spreading said powder layer by layer on a predetermined platform;
d. selectively fusing said powder using at least one energy source selected from the group consisting of laser, electron beam and the like to perform printing operation to obtain an air intake outer casing with build platform;
e. transferring said an air intake outer casing with build platform to a furnace in order to heat said air intake outer casing with build platform at a predetermined temperature to obtain heat processed air intake outer casing with build platform; and
f. subjecting said heat processed air intake outer casing with build platform to wire cutting operation to separate the air intake outer casing from the build platform followed by shot blasting to generate compressive residual stresses on the surfaces of the air intake outer casing and buffing operation to obtain the air intake outer casing with pre-determined surface finish.

2. The process as claimed in claim 1, wherein the process comprises a pre-step of printing a support having predetermined configuration meant for holding said air intake outer casing and transferring heat from the material being 3D printed to the platform during printing operation.

3. The process as claimed in claim 1, wherein the metal powder is selected from group consisting of , Nickel based alloy, Titanium alloys, Aluminum alloy and Steel alloy or any other thereof, and wherein the temperature of the platform is set at temperature ranging from 80 to 1650C.

4. The process as claimed in claims 1 to 3, wherein the metal powder is Nickel based alloy preferably IN718 and the platform temperature is in the range of 110 to 130ºC, preferably at 120ºC.

5. The process as claimed in claims 1 to 3, wherein the metal powder is Aluminium alloy and the platform temperature is in the range of 120-1650C preferably at 155ºC.

6. The process as claimed in claims 1 to 3, wherein the metal powder is Steel alloy preferably SS316L and the platform temperature is in the range of 80-1200C preferably at 110ºC.

7. The process as claimed in claims 1 to 3, wherein the metal powder is Titanium Alloy preferably Ti6Al4V and the platform temperature is in the range of 120-1650C preferably at 160ºC..

8. The process as claimed in claim 1, wherein the air intake outer casing being designed and rendered using a rendering software, is used as an input for the additive manufacturing process.

9. The process as claimed in claim 1, wherein the layer has a thickness in the range of 0.02 to 0.08 mm, preferably 0.02 mm and a laser strip width in the range of 5 to 10 mm, preferably 5mm.

10. The process as claimed in claim 1, wherein the overlap between the layers is in the range of 0.10 to 0.15 mm, preferably 0.12 mm.

11. The process as claimed in claim 1, wherein the spreading comprises depositing layers of a metal powder sequentially one upon the other to form features.

12. The process as claimed in claim 1, wherein the energy source is selected from the group consisting of laser beam and electron beam, wherein the energy source has a scanning speed of about 800 to 1400 mm/second, preferably 1000mm/second and has power of 80 to 400 watt, preferably 195 watt.

13. The process as claimed in claim 1, wherein the heat treating step involves the following steps for Nickel Based Alloy preferably IN718:
? annealing the air intake outer casing with build platform at a temperature ranging from 1000 to 1200 °C for a period ranging from 30 minutes to 120 minutes in an inert Argon atmosphere followed by cooling to room temperature;
? ageing the air intake outer casing with build platform by holding the casing with build platform at a temperature ranging from 700 to 800°C for a time period ranging from 5 to 10 hours in an inert Argon atmosphere followed by cooling to a temperature ranging from 625 to 675°C in 1 to 3 hours and holding at a temperature ranging from 625 to 675°C for 6 to 10 hours in an inert Argon atmosphere; and
? air cooling said air intake outer casing with build platform to room temperature.

14. The process as claimed in claim 1, wherein the metal powder is from Nickel Based Alloy preferably IN718 and the heat treatment comprises solution annealing the air intake outer casing with build platform at 1065 °C for one hour in an inert Argon atmosphere, followed by air cooling to room temperature; holding the air intake outer casing with build platform at 760 °C for ten hours in an inert Argon atmosphere followed by furnace cooled to 650 °C in two hours, holding at 650 °C for eight hours in an inert Argon atmosphere and air cooling to the room temperature.

15. The process as claimed in claim 1, wherein the metal powder is from Aluminium alloy and the heat treating step is carried out on said air intake casing with build platform by aging said air intake casing with build platform at 330°C for 2 hours and air cooling.

16. The process as claimed in claim 1, wherein the metal powder is from Titanium alloy preferably Ti6Al4V and the heat treatment comprises stress reliving heat treatment at 650 °C for 3 hrs. in an inert argon atmosphere, followed by air cooling and heating at 800°C up to 1 to 4 hrs. in an inert argon atmosphere followed by air cooling.

17. The process as claimed in claim 1, wherein the metal powder is from Steel alloy preferably SS316L and the heat treatment comprises stress reliving heat treatment at 1066 °C for 1.5 hrs. followed by air cooling to increase ductility and reduce tensile strength.

18. The process as claimed in claim 1, wherein the support is selected from Block type, Line type, Point type, Web Type, Contour type, Gusset type, Hybrid type and Volume type, preferably, the support is combination of block support with hatching teeth and perforation type support, volume support and hybrid support wherein the height of said support is selected from the range of 55 mm to 2 mm.

19. A process for manufacturing an air intake outer casing, said process comprising the following steps:
a) generating a CAD model using computer aided design;
b) converting the model into a Stereolithography / Surface Tesselation Language / Standard Triangulation Language file (STL);
c) generating additive manufacturing program by importing STL file into a MAGICS MATERIALISE software adapted to define part orientation and generate support;
d) transferring the STL file to a slicer software for slicing;
e) importing the file in an EOSPRINT software adapted for assigning the build parameters which are further optimized for CAD data;
f) designing parameters selected from laser power, scanning speed, hatch distance and layer thickness;
g) exporting the file to the 3D printing machine for producing the air intake outer casing.
h) spreading metal powder layer by layer on a predetermined platform;
i) selectively fusing said metal powder using at least one energy source at predetermined conditions to perform a printing operation to obtain the air intake outer casing with build platform;
j) heat treating said air intake outer casing with build platform in a furnace at a predetermined temperature to obtain heat treated air intake outer casing with build platform followed by cooling to room temperature to obtain heat treated air intake outer casing with build platform;
k) subjecting said heat treated air intake outer casing with build platform to wire cutting operation to separate the air intake outer casing from the build platform, followed by shot blasting to generate compressive residual stresses on the surfaces of the air intake outer casing, and buffing operation to achieve the air intake outer casing with pre-determined surface finish.

20. An air intake outer casing (100) obtained by the process as claimed in claim 1 to 19.

21. The air intake outer casing as claimed in claim 20, is made of Nickel Based Alloy metal powder and said air intake outer casing exhibits a tensile strength of >1241 MPa, a yield strength of about 1150MPa and a hardness of about 47 HRC.

22. The air intake outer casing as claimed in claim 20, is made of Aluminium alloy metal powder and said air intake outer casing exhibits a yield strength of about 210MPa and a hardness of about 107 HV.

23. The air intake outer casing as claimed in claim 20, is made of Titanium metal powder and said air intake outer casing exhibits a yield strength of about 1070MPa and a hardness of about 40HRC.

24. The air intake outer casing as claimed in claim 20, is made of Steel alloy metal powder and said air intake outer casing exhibits a yield strength of about 470MPa and a hardness of about 32HRC.

25. A system for manufacturing air intake casing by 3D printing method, said system comprises a 3D printing device and a support, wherein the support comprises teeth/grooves adapted to enable easy removal of supports, wherein height of support corresponds to height of build platform in order to dissipate heat between build platform and job at the time of part building and avoiding distortion of the air intake outer casing.

Dated this 31st day of March, 2019

CHIRAG TANNA
of NOVO IP
APPLICANT’S PATENT AGENT