DESC:FIELD OF THE INVENTION
The present invention relates to manufacturing of an aerospace part. Particularly present invention relates to a method of manufacturing of a diffuser, used in a jet engine, using an additive manufacturing process.

BACKGROUND OF THE INVENTION
The diffuser plays an important role in the aero engine inlet section. Air leaves the compressor through exit guide vanes, which convert the radial component of the air flow out of the compressor to straight-line flow. The air then enters the diffuser section of the engine, which is a divergent duct. The primary function of the diffuser structure is aerodynamic. The divergent duct shape converts most of the air’s velocity into static pressure. As a result, the highest static pressure and lowest velocity in the entire engine is at the point of diffuser discharge and combustor inlet. Other aerodynamic design considerations that are important in the diffuser section arise from the need for a short flow path, uniform flow distribution, and low drag loss. In addition to critical aerodynamic functions, the diffuser also provides:
? Engine structural support, including engine mounting to the nacelle.
? Support for the rear compressor bearings and seals.
Manufacturing of diffuser has always been a challenging task due to its complex shape, blades profile, fuel passing holes and integral features for various mountings. Traditionally, diffuser is manufactured by 5 axis machining from a solid block. The traditional manufacturing methods have the following drawbacks:
? Large amount of raw material is wasted in traditional manufacturing method.
? The machining processes demand various specialized tools & high end machines which are economical for mass production only.
Another disadvantage is the overall cost involved, especially for short-run productions.
To overcome the above drawbacks, additive manufacturing method has been envisaged in the present invention. The additive manufacturing is a novel manufacturing method in which diffuser with integral features is produced. In this manufacturing method diffuser is made by using digital model and layer by layer material build-up approach. This tool-less manufacturing method can produce a uniform diffuser with casing in a short time with high precision.

OBJECTS OF THE INVENTION
Some of the objects of the present disclosure which at least one embodiment herein satisfies are as follows:
It is an object of the present invention to provide a diffuser with its features.
It is another object of the present invention to provide an additive manufacturing method for manufacturing the integral diffuser.
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 DRAWINGS
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates the diffuser (100) printed by additive manufacturing method.
Figure 2 shows the flow chart of diffuser manufacturing by additive manufacturing process.
SUMMARY OF THE INVENTION
Increased productivity and reduced cost of production is achieved by reducing the number of steps in manufacturing processes. The additive manufacturing approach eliminates the rough and 5 axis machining processes in the diffuser manufacturing.
According to one embodiment of the present invention, diffuser is manufactured in a single print by an additive manufacturing process. The present invention describes elimination of rough machining (Blanking, turning, drilling, tapping etc.) to make an integral part.
According to the present invention, the process for manufacturing an integral diffuser in a single print by an additive manufacturing process comprises: providing metal powder as a raw material to a 3D printing device, spreading the powder, layer by layer, on a predetermined platform of device, selectively fusing said powder using at least one energy source to perform printing operation to obtain a diffuser with a build platform, transferring said diffuser with build platform to a furnace to heat treat it at a predetermined temperature to obtain a heat treated diffuser with build platform, wire cutting the heat treated diffuser to separate it from the build platform to obtain a separated diffuser, shot blasting the separated diffuser to generate compressive residual stresses on its surfaces to obtain a shot blasted diffuser, performing buffing/Micro machining polishing (MMP) operation on the shot blasted integral diffuser to achieve the final integral diffuser (100) with pre-determined surface finish and finally inspecting the integral diffuser (100) with NDT testing.
In another aspect the present invention also provides an integral diffuser made by 3D printing process.

DESCRIPTION OF THE INVENTION
The present invention relates to manufacturing of a diffuser for jet engines using a selective laser sintering process. The key inventive feature of this invention is the design and development of the diffuser and the manufacturing process to make the same.
In accordance with one aspect of invention, there is provided an integral diffuser (as shown in Figure 1) manufactured by the invented process, said diffuser being an integral diffuser (100) comprising vanes / blades (12) with leading and tailing edges, fuel channel, cage shaft mounting holes (14), sealing ring mounting holes (16), igniter mounting (18), EGT mounting (20), fuel supply tube mounting (22), and main fuel inlet mounting (24), in that, said diffuser blades (12) have sharp edges which converges to a single point at end, characterised in that, said edge being computed wherein total beam offset equates the sum of global beam offset, part beam offset, and edge offset.
Figure 2 illustrates an integral diffuser (100) manufacturing process. In one embodiment, the process for manufacturing an integral diffuser (100) in a single print by an additive manufacturing process, comprises the following steps:
? In the first step, metal powder as a raw material is provided. The metal powder is selected from a group consisting of Nickel based alloys, titanium alloys, steels and Aluminium Alloy.
? In the next step, a 3D printing device is provided.
? In the next step, the metal powder is spread, layer by layer, on a pre-determined platform.
? In the next step, the metal powder is fused using at least one energy source selected from the group consisting of laser and electron beam to perform printing operation to obtain a diffuser with a build platform.
? In the next step, the diffuser with build platform is transferred to a furnace in order to heat treat the diffuser with build platform at a predetermined temperature to obtain a heat treated diffuser with build platform.
? In the next step, heat treated diffuser with build platform is subjected to wire cutting operation to separate the diffuser from the build platform to obtain a separated diffuser.
? The separated diffuser is subjected to shot blasting to generate compressive residual stresses on the surfaces of said separated diffuser to obtain a shot blasted diffuser.
? In the next step, the shot blasted integral diffuser is subjected to buffing/MMP operation to achieve the final integral diffuser with pre-determined surface finish and
? Finally, the final integral diffuser (100) is subjected to NDT testing.

In accordance with another aspect of the present invention there is provided a system for manufacturing an integral diffuser (100) 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 the supports, wherein height of the 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 integral diffuser.
In one embodiment, the process described herein above comprises a pre-step of printing a support having predetermined configuration based on the quantity of material required for supports, heat dissipation of product to surrounding and geometry of the model. The support is selected from a group of supports consisting of a block type support, a line type support, a point type support, a web type support, a contour type support, a Gusset type support, a hybrid type support and a volume type support. In one preferred embodiment, block type support is selected for the present invention.
The block type support comprises different features selected from a group of features consisting of hatching features, hatching teeth features, fragmentation features, border features, border teeth features, perforation features, and gusset borders features. In one preferred embodiment hatching, fragmentation and perforation features of block type support are selected for the present invention.
In one embodiment, the metal powder is spread on said build-up platform layer by layer. In one embodiment, the spreading comprises controlled deposition of the layers of metal powder to form the integral diffuser. In one embodiment, the spreading comprises depositing layers of a metal powder sequentially one upon the other to form features with a layer thickness in-between 0.020 mm to 0.080 mm. In one preferred embodiment, the layer thickness is 0.02 mm.
In one embodiment, the laser strip width is in the range of 3 to 10 mm and the overlap between the layers is in the range of 0.10 to 0.15 mm. In one preferred embodiment, the laser strip width is of 5 mm and the overlap between the layers is 0.12 mm.
In one embodiment, the metal powder is spread on said build-up platform layer by layer, characterised in that, said platform temperature is maintained around 80 ºC to 165 ºC throughout said process, preferably at 120 ºC.
In one embodiment, the step of spreading said powder, layer by layer, on a predetermined platform, characterised in that, after each layer, powder is selectively fused by using 80 to 400 watt laser power, with a scanning speed between 800 mm/Sec and 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.
In one embodiment, the heat treated diffuser with build platform is subjected to post heat treatment processes of wire cutting operation to separate the diffuser from the build platform and thus, obtain a separated diffuser.
In another embodiment, the separated diffuser is subjected to shot blasting to generate compressive residual stresses on the surfaces to obtain a shot blasted diffuser. In one embodiment, said shot blasting process is characterised in that, said shot blasting is carried out using steel balls of 0.7 mm diameter and/or ceramic balls of 0.1 mm diameter, to obtain a shot blasted diffuser.
In yet another embodiment, as part of post heat treatment processes, a buffing operation is performed on the said shot blasted diffuser to obtain the final integral diffuser (100) with a predetermined surface finish.
In another embodiment, post heat treatment processes comprises a step of micro machining to achieve mirror-like finish on said integral diffuser (100).
In one embodiment, the process for manufacturing an integral diffuser (100) in a single print by an additive manufacturing process serially includes CAD Model generation, additive manufacturing program generation, Additive Manufacturing or 3D printing, said process comprising the steps of:
? generating a CAD model using computer aided design;
? converting the model into a Stereolithography / Surface Tesselation Language / Standard Triangulation Language file (STL);
? generating additive manufacturing program by importing STL file into a 3D printing part file preparation software like MAGICS MATERIALISE adapted to define part orientation and generate support;
? transferring the STL file to a slicer software for slicing;
? importing the file in an 3D printing machine software like EOSPRINT adapted for assigning the build parameters which are further optimized for CAD data;
? designing parameters selected from laser power, scanning speed, hatch distance and layer thickness;
? exporting the file to the 3D printing machine for producing the integral diffuser.
? spreading metal powder layer by layer on a predetermined platform; and
? selectively fusing said metal powder using at least one energy source at predetermined conditions to perform a printing operation to obtain the diffuser with build platform.
In accordance with an implementation, the step of CAD Model generation includes producing a digital model as the first step in the additive manufacturing process. The digital model is produced by using computer-aided design (CAD). Then this CAD model is converted into the stereo lithography / Surface Tesselation Language / Standard Triangulation Language file (STL) which is used by further portions and processes of this invention.
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 3D printing part file preparation software. In a preferred embodiment, MAGICS materialise software is used as 3D printing part file preparation software. In MAGICS materialise software, part orientation and support generation takes place. Then STL file is sent to the slicer software for slicing. After slicing, the file is imported in a 3D printing machine software. In a preferred embodiment, EOSPRINT software is used as 3D printing machine 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, the file is exported to the 3D printing machine for final printing.
The parameters used during the various process steps of the method of manufacturing of present invention depend on the type of raw material powder being used. The process parameters used for different material grades of powder is given in following sections.
In one embodiment, the metal powder is Nickel based alloy, preferably IN718 and the platform temperature during additive manufacturing is in the range of 110 to 130 ºC, preferably 120 ºC.
In one preferred embodiment, the heat treatment process involves the following steps for Nickel Based Alloy preferably IN718:
Step A: solution annealing the diffuser 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 diffuser with build platform.
Step B: ageing the diffuser 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 furnace 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 diffuser with build platform.
Step C: air cooling said diffuser with build platform to room temperature to obtain a heat treated diffuser with build platform.
In one embodiment, the metal powder is a Nickel Based Alloy, preferably IN718 and heat treatment of the diffuser comprises solution annealing the diffuser with build platform at 1065 °C for one hour in an inert Argon atmosphere, followed by air cooling to room temperature; holding the diffuser with build platform at 760 °C for ten hours in an inert Argon atmosphere followed by furnace cooling 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.
The summary of parameters used to produce the integral diffuser from the IN718 (Nickel Based Alloy) in additive manufacturing is mentioned in table 1.
Table 1
Parameters Value
Part (integral diffuser)
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 integral diffuser
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

In one embodiment, the metal powder is Aluminium alloy, preferably AlSi10Mg and the platform temperature during additive manufacturing is in the range of 120-165 ºC, preferably 155ºC.
In one embodiment, the metal powder is an Aluminium alloy AlSi10Mg and heat treatment of the diffuser is carried out on said diffuser with build platform by aging said diffuser with build platform at 330 °C for 2 hours and air cooling.

In one embodiment, the metal powder is Titanium Alloy, preferably Ti6Al4V and the platform temperature during additive manufacturing is in the range of 120-165 ºC preferably 160ºC.
In one embodiment, the metal powder is a Titanium alloy preferably Ti6Al4V and heat treatment of the diffuser comprises stress reliving heat treatment at 650 °C for 3 hours in an inert argon atmosphere, followed by air cooling and heating at 800 °C up to 1 to 4 hours in an inert argon atmosphere followed by air cooling.
In one embodiment, the metal powder is Steel alloy, preferably SS316L and the platform temperature during additive manufacturing is in the range of 80-120 ºC, preferably 110 ºC.
In one embodiment, the metal powder is from Steel alloy preferably SS316L and heat treatment of the diffuser comprises stress reliving heat treatment at 1066 °C for 1.5 hours followed by air cooling to increase ductility and reduce tensile strength.
The summary of parameters used to produce the integral diffuser from Aluminium, Steel and Titanium alloy in additive manufacturing is shown in Table 2:
Table 2
Parameter \Material Aluminum (AlSi10Mg) Steel (SS316L) Titanium (Ti6AI4V)
Layer thickness 0.030 mm to 0.060 mm 0.020 mm to 0.060 mm 0.030 mm to 0.060 mm
Platform Temperature 120 to 165 0C 80 to 120 0C 120 to 165 0C
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 800 mm/sec to 1400 mm/sec 800 mm/sec to 1400 mm/sec 800 mm/sec to 1400 mm/sec
Tensile Strength Min 360 MPa Min 540 MPa Min 1200 MPa

EXAMPLE 1:
In one non-limiting illustrative embodiment integral diffuser (100) is manufactured by the present method using IN718 material. Heat treatment is carried out on the diffuser with build platform to achieve the mechanical properties. Firstly, the diffuser with build platform is solution annealed in an inert Argon atmosphere. The diffuser with build 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 diffuser with build 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 diffuser with build platform is air cooled to the room temperature.
The mechanical properties achieved after heat treatment are summarised in table 3 (Material: 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 HRC

EXAMPLE 2:
In another embodiment, Aluminium Alloy preferably AlSi10Mg is used to prepare the integral diffuser (100). A heat treatment is carried out on a diffuser with build platform to achieve the mechanical properties. Solution annealing is not required. The diffuser with built platform is aged at 330 °C for 2 hours, followed by air cooling.
In one embodiment, there is provided an integral diffuser being made of an Aluminium Alloy preferably AlSi10Mg and manufactured by process as described herein above, said diffuser (100) characterized in that, it exhibits tensile strength >360 MPa, yield strength 210 MPa, elongation 6%, and hardness 107 HV.
The mechanical properties of the integral diffuser (100), manufactured by the present method using Aluminium Alloy AlSi10Mg, achieved after heat treatment are summarised in table 4.

EXAMPLE 3:
In still another embodiment, steel alloy, preferably SS316L is used to prepare the integral diffuser (100). Annealing heat treatment is carried out on SS316L 3D Printed parts with build platform to achieve the mechanical properties. Heating is carried out at 1066 °C for 1.5 hours followed by air cooling.
The mechanical properties of the integral diffuser (100), manufactured by the present method using Steel, achieved after heat treatment are summarised in table 4.

EXAMPLE 4:
In yet another embodiment, Titanium alloy, preferably Ti6Al4V is used to prepare the integral diffuser. The heat treatment is carried out on Ti6Al4V 3D printed parts with build platform to achieve the mechanical properties. Firstly, stress reliving heat treatment with build platform is carried out at 650 °C for 3 hours 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 hours in an inert argon atmosphere followed by air cooling.
The mechanical properties of the integral diffuser (100), manufactured by the present method using Titanium alloy, 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 (AlSi10Mg) Steel (SS316L) Titanium (Ti6Al4V)
Yield strength 210 MPa 470MPa 1070 MPa
Elongation 6% 50% 11%
Hardness 107 HV 32 HRC 39 HRC
In an example, the step of wire cutting & support removal is implemented to separate the heat treated diffuser from the build platform. Next, the support formed during the 3D printing operation is machined off.
In another example, the step of shot blasting is performed after wire cutting to generate the compressive residual stresses on integral diffuser surface. The shot blasting is carried out using steel balls of 0.7 mm dia. and/or ceramic balls of 0.1 mm dia.
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 has benefits like reduction in friction, extremely low material removal, homogeneity of treatment across entire surface and respect of tolerances.
Finally, the integral diffuser (100) 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.
The integral diffuser (100) is characterized by at least one characteristic selected from tensile strength >360 MPa, yield strength >200 MPa, elongation >5%, and hardness >30 HV.
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 manufacturing an integral diffuser (100) in a single print by an additive manufacturing process, said process comprising the steps of:
a. providing metal powder as a raw material, wherein said metal powder is selected from a group consisting of Nickel based alloys, titanium alloys, steels and Aluminium 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 and electron beam to perform printing operation to obtain a diffuser with a build platform;
e. transferring said diffuser with the build platform to a furnace in order to heat treat said diffuser with build platform at a predetermined temperature to obtain heat treated diffuser with build platform; and
f. subjecting said heat treated diffuser with build platform to a wire cutting operation followed by a step of shot blasting and MMP / buffing operation to obtain said integral diffuser (100).

2. A process for manufacturing an integral diffuser (100) in a single print by an additive manufacturing process, said process comprising the steps of:
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 3D printing part file preparation software preferably 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 a 3D printing machine software preferably 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 a 3D printing machine for producing the integral diffuser.
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 diffuser with build platform;
j. heat treating said diffuser with build platform to obtain a heat treated diffuser with build platform;
k. subjecting said heat treated diffuser with build platform to wire cutting operation to separate the diffuser from the build platform to obtain a separated diffuser;
l. shot blasting, to generate compressive residual stresses on the surfaces of the diffuser, to obtain a shot blasted diffuser;
m. buffing/MMP operation on said shot blasted diffuser to achieve the final integral diffuser (100) with pre-determined surface finish; and
n. NDT testing of the final integral diffuser (100).

3. The process as claimed in claim 1 or 2, wherein said process comprising a pre-step of printing a support before printing the said diffuser with build platform, having predetermined configuration based on the quantity of material required for supports, heat dissipation of product to surrounding and geometry of model
wherein said support is selected from a group of supports consisting of a block type support, a line type support, a point type support, a web type support, a contour type support, a Gusset type support, a hybrid type support, and a volume type support wherein a block type support is selected,
wherein said block type support comprises different features selected from a group of features consisting of hatching features, hatching teeth features, fragmentation features, border features, border teeth features, perforation features, and gusset borders features wherein hatching, fragmentation and perforation features of said block type support is selected.

4. The process as claimed in any of claims 1 to 3, wherein the temperature of the platform is set at temperature ranging from 80 to 165 ºC, wherein said metal powder is spread on said build-up platform layer by layer with a layer thickness from 0.020 mm to 0.080 mm, preferably 0.02 mm, wherein a laser strip width is in the range of 3 to 10 mm and wherein the overlap between the layers is in the range of 0.10 to 0.15 mm.

5. The process as claimed in any of claims 1 to 4, wherein the metal powder is Nickel based alloy, preferably IN718 and the platform temperature is in the range of 110 to 130 ºC, preferably 120 ºC, or
the metal powder is Aluminium alloy, preferably AlSi10Mg and the platform temperature is in the range of 120-165 ºC, preferably 155 ºC, or
the metal powder is Steel alloy, preferably SS316L and the platform temperature is in the range of 80-120 ºC, preferably 110 ºC, or
the metal powder is Titanium Alloy, preferably Ti6Al4V and the platform temperature is in the range of 120-165 ºC preferably 160ºC.

6. The process as claimed in any of claims 1 to 5, wherein the heat treatment of diffuser involves the following steps for Nickel Based Alloy, preferably IN718:
? annealing the diffuser with build platform at a temperature ranging from 1000 to 1200 °C, preferably at 1065°C for a period ranging from 30 minutes to 120 minutes, preferably 60 minutes in an inert Argon atmosphere followed by cooling to room temperature;
? ageing the diffuser with build platform by holding the diffuser with build platform at a temperature ranging from 700 to 800 °C, preferably 760 °C for a time period ranging from 5 to 10 hours, preferably 10 hours in an inert Argon atmosphere followed by cooling to a temperature ranging from 625 to 675 °C, preferably 650 °C in 1 to 3 hours, preferably 2 hours and holding at a temperature ranging from 625 to 675 °C, preferably 650 °C for 6 to 10 hours, preferably 8 hours in an inert Argon atmosphere; and
? air cooling said diffuser with build platform to room temperature.

7. The process as claimed in any of claims 1 to 5, wherein the metal powder is an Aluminium alloy preferably AlSi10Mg and heat treatment of the diffuser is carried out on said diffuser with build platform by aging said diffuser with build platform at 330 °C for 2 hours and air cooling,
wherein the metal powder is from Titanium alloy preferably Ti6Al4V and heat treatment of the diffuser 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
wherein the metal powder is from Steel alloy preferably SS316L and heat treatment of the diffuser comprises stress reliving heat treatment at 1066 °C for 1.5 hrs. followed by air cooling to increase ductility and reduce tensile strength.

8. The process as claimed in any of claims 1 to 7, wherein said step of spreading said powder, layer by layer, on a predetermined platform, characterised in that, after each layer, powder being selectively fused by using 80 to 400 watt laser power, with a scanning speed between 800 mm/Sec and 1400 mm/Sec in an Argon environment.

9. The process as claimed in any of claims 1 to 8, wherein said process comprising a step of a shot blasting operation to generate compressive residual stresses on surfaces of said separated diffuser, characterised in that, said shot blasting being carried out using steel balls of 0.7 mm diameter and/or ceramic balls of 0.1 mm diameter, to obtain a shot blasted diffuser.

10. An integral diffuser manufactured by the process as claimed in any of claims 1 to 9, said diffuser being an integral diffuser (100) comprising vanes / blades (12) with leading and tailing edges, fuel channel, cage shaft mounting holes (14), sealing ring mounting holes (16), igniter mounting (18), EGT mounting (20), fuel supply tube mounting (22), and main fuel inlet mounting (24), in that, said diffuser blades (12) having sharp edges which converges to a single point at end, characterised in that, said edge being computed wherein total beam offset equates the sum of global beam offset, part beam offset, and edge offset,
wherein said integral diffuser characterized by at least one characteristic selected from tensile strength >360 MPa, yield strength >200 MPa, elongation >5%, and hardness >30 HV.

11. A system for manufacturing the integral diffuser of claim 10 by 3D printing method as claimed in any of claims 1 to 9, 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 integral diffuser.