Near Net Shape Forming Process of a Titanium Alloy Component Using Hot Isostatic Pressing with Graphite Mould

2014 ◽  
Vol 599-601 ◽  
pp. 81-87
Author(s):  
Peng Ju Xue ◽  
Yan Wu ◽  
Jun Huang ◽  
Qing Song Wei ◽  
Yu Sheng Shi ◽  
...  
Keyword(s):  
Mild Steel ◽  
Hot Isostatic Pressing ◽  
Free Layer ◽  
Forming Process ◽  
Machined Surface ◽  
Isostatic Pressing ◽  
Isolation Layer ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Graphite Mould

Ti6Al4V component has been formed by hot isostatic pressing (HIPping) using internal graphite mould with Ni isolation layer. The shape of the graphite had no deformation after HIPping. The Ni isolation layer with a thickness of approximately 5μm on graphite before HIPping was diffused into the dense Ti6Al4V component surface and formed a uniform, compact and crack free layer with a thickness of approximately 100μm after HIPping. The Ni diffusion layer is not damaged after removing the graphite mould by unpolluted sandblasting. The interface topography and the elements diffusion have been assessed and it is found that the non-machined surface of Ti6Al4V component was improved by using graphite mould than those used mild steel. The roughness of non-machined surface after removing the graphite mould by sandblasting is Ra=1.6μm, and the roughness of non-machined surface after removing the mild steel by acid pickling is Ra=10.8μm. It is concluded that graphite mould could be used for the HIPping process to produce complex-shaped components.

An Optimal Container Design for Metal Powder Under Hot Isostatic Pressing

2001 ◽  
Vol 123 (2) ◽  
pp. 234-239 ◽  
Author(s):  
S. H. Chung ◽  
H. Park ◽  
K. D. Jeon ◽  
K. T. Kim ◽  
S. M. Hwang
Keyword(s):  
Stainless Steel ◽  
Powder Compact ◽  
316L Stainless Steel ◽  
Hot Isostatic Pressing ◽  
Steel Powder ◽  
Design Sensitivity ◽  
Stainless Steel Powder ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Net Shape Forming

Near-net-shape forming of 316L stainless-steel powder was investigated under hot isostatic pressing. To simulate densification and deformation of a powder compact in a container during hot isostatic pressing, the constitutive model of Abouaf and co-workers was implemented into a finite element analysis. An optimal design technique based on the evaluation schemes of the design sensitivity was used to acquire the desired final shape of a powder compact. Experimental data of 316L stainless steel powder showed that the optimally designed container allowed near-net-shape forming of the desired powder compact during hot isostatic pressing.

Producing HP Pump Barrels Utilizing Powder Metallurgy and Hot Isostatic Pressing

2009 ◽  
Author(s):  
Martin Bjurstro¨m ◽  
Carl-Gustaf Hjorth
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Isostatic Pressing ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Uniform Structure ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Hip Process

The fabrication of near net shape powder metal (PM) components by hot isostatic pressing (HIP) has been an important manufacturing technology for steel and stainless steel alloys since about 1985. The manufacturing process involves inert gas atomization of powder, 3D CAD capsule design, sheet metal capsule fabrication and densification by HIP in very large pressure vessels. Since 1985, several thousand tonnes of parts have been produced. The major applications are found in the oil and gas industry especially in offshore applications, the industrial power generation industry, and traditional engineering industries. Typically, the components replace castings, forgings and fabricated parts and are produced in high alloy grades such as martensitic steels, austenitic stainless steels, duplex (ferritic/austenitic) stainless steels and nickel based superalloys. The application of PM/HIP near net shapes to pump barrels for medium to high pressure use has a number of advantages compared to the traditional forging and welding approach. First, the need for machining of the components is reduced to a minimum and welding during final assembly is reduced substantially. Mechanical properties of the PM/HIP parts are isotropic and equal to the best forged properties in the flow direction. This derives from the fine microstructure using powder powder and the uniform structure from the HIP process. Furthermore, when using the PM HIP process the parts are produced near net shape with supports, nozzles and flanges integrated. This significantly reduces manufacturing lead-time and gives greater design flexibility which improves cost for the final component. The PM HIP near net shape route has received approval from ASTM, NACE and API for specific steel, stainless steel and nickel base alloys. This paper reviews the manufacturing sequence for PM near net shapes and discusses the details of several successful applications. The application of the PM/HIP process to high pressure pump barrels is highlighted.

Producing HP Pump Barrels Utilizing Powder Metallurgy and Hot Isostatic Pressing

2009 ◽  
Author(s):  
Martin Bjurstro¨m ◽  
Carl-Gustaf Hjorth
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Isostatic Pressing ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Uniform Structure ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Hip Process

The fabrication of near net shape powder metal (PM) components by hot isostatic pressing (HIP) has been an important manufacturing technology for steel and stainless steel alloys since about 1985. The manufacturing process involves inert gas atomization of powder, 3D CAD capsule design, sheet metal capsule fabrication and densification by HIP in very large pressure vessels. Since 1985, several thousand tonnes of parts have been produced. The major applications are found in the oil and gas industry especially in offshore applications, the industrial power generation industry, and traditional engineering industries. Typically, the components replace castings, forgings and fabricated parts and are produced in high alloy grades such as martensitic steels, austenitic stainless steels, duplex (ferritic/austenitic) stainless steels and nickel based superalloys. The application of PM/HIP near net shapes to pump barrels for medium to high pressure use has a number of advantages compared to the traditional forging and welding approach. First, the need for machining of the components is reduced to a minimum and welding during final assembly is reduced substantially. Mechanical properties of the PM/HIP parts are isotropic and equal to the best forged properties in the flow direction. This derives from the fine microstructure using powder powder and the uniform structure from the HIP process. Furthermore, when using the PM HIP process the parts are produced near net shape with supports, nozzles and flanges integrated. This significantly reduces manufacturing lead-time and gives greater design flexibility which improves cost for the final component. The PM HIP near net shape route has received approval from ASTM, NACE and API for specific steel, stainless steel and nickel base alloys. This paper reviews the manufacturing sequence for PM near net shapes and discusses the details of several successful applications. The application of the PM/HIP process to high pressure pump barrels is highlighted.

Hot Isostatic Pressing of Ti6Al4V Alloys Monolithic Bladed Disks

2014 ◽  
Vol 496-500 ◽  
pp. 279-283 ◽  
Author(s):  
Peng Ju Xue ◽  
Yan Wu ◽  
Qing Song Wei ◽  
Yu Sheng Shi
Keyword(s):  
Tensile Strength ◽  
Hot Isostatic Pressing ◽  
Fracture Morphology ◽  
Bladed Disks ◽  
Isostatic Pressing ◽  
Bladed Disk ◽  
Near Net Shape ◽  
Near Net Shaping ◽  
Net Shaping ◽  
Parts Manufacturing

Near-net-shaping hot isostatic pressing (NNS-HIP) method was used for once-forming complex monolithic Ti6Al4V alloy bladed disks manufacturing. The complex monolithic bladed disks were formed successfully in a near-net-shape manner using the proposed HIP mold scheme in this study. The results showed that there were fine and homogeneous strip α+β phases and no obvious pores or cracks were detected. A "layered" phenomenon was observed in as-built part microstructure. The tensile strength value of specimens from the NNS-HIP bladed disks in the same furnace reached 900MPa, which was higher than the values of parts manufactured using casting and forging processes. The fracture morphology analysis showed that the sample had a ductile fracture. This study provides a reference to the NNS-HIP for the bladed disk parts manufacturing.

The Implementation of Spray Forming for High Temperature Casing Applications

2001 ◽  
Author(s):  
Alan Partridge ◽  
Michael B. Henderson ◽  
David G. Cole ◽  
Paul Andrews
Keyword(s):  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Spray Forming ◽  
Ring Rolling ◽  
Lead Times ◽  
Forming Process ◽  
Fine Grained ◽  
Near Net Shape ◽  
Property Assessment ◽  
Processing Steps

Many current gas turbine casings are manufactured using conventional wrought processing routes. Although well established this approach often requires numerous and complex processing steps. This can result in relatively long component lead times and high part costs. In an attempt to reduce lead times and cost the production of parts using the spray-forming process is under consideration. In the spray forming process the material is deposited from the molten state to produce a near net shape ring. The deposited ring is then subject to hot isostatic pressing (HIP) and/or ring rolling to consolidate the material and expand the ring to the required size. The material thus produced is usually relatively fine grained and can have a different balance of properties compared to conventionally processed alloys. However, the major advantage is that cost reductions can be achieved through the elimination of many process steps. In the current work a high temperature nickel alloy, RS5, has been produced as a spray formed ring. The influence of HIP and ring rolling have been investigated and a detailed microstructure-mechanical property assessment of the material has been carried out. The results of this work will be reported and the implications of the work on cost and manufacturing issues will be discussed.

Numerical Simulation of the Auto Claw-Pole Thixoforming Process

2011 ◽  
Vol 66-68 ◽  
pp. 1605-1610
Author(s):  
Van Luu Dao ◽  
Sheng Dun Zhao ◽  
Wen Jie Lin
Keyword(s):  
Complex Geometry ◽  
Hot Forging ◽  
Strong Impact ◽  
Forming Process ◽  
Billet Temperature ◽  
Punch Speed ◽  
Initial Billet ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Die Temperature

Thixoforming is an effective near-net-shape forming process to produce components with complex geometry and in fewer forming steps. In this study, thixoforming was used to replace the conventional hot forging to form the auto claw-pole. The finite element code Forge2008Ó was used to simulate the auto claw-pole thixoforming process. The results show that initial billet temperature, punch speed, die temperature and friction have strong impact on the forming process. Finally, the reasonable process parameters for the auto claw-pole thixoforming were obtained: initial billet temperature 1430~1440°C, punch speed 100~200mm/s and die temperature 300~400°C.

Novel Direct Coagulation Casting of Alumina Suspensions Using Y3+-Ion Releasing Substances as Coagulant

2014 ◽  
Vol 602-603 ◽  
pp. 164-169
Author(s):  
Yue Dong ◽  
Xiao Dong Li ◽  
Shao Hong Liu ◽  
Ji Guang Li ◽  
Xu Dong Sun
Keyword(s):  
Complex Shape ◽  
High Density ◽  
Green Body ◽  
Alumina Ceramics ◽  
Forming Process ◽  
Coagulation Time ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Alumina Suspensions

Direct coagulation casting (DCC) is a relatively new ceramic near-net-shape forming process which can form homogeneous ceramic green body with complex shape and high density. Direct coagulation casting of aqueous alumina slurries by adding Y3+ions, which have been frequently used as additive for the sintering of alumina ceramics, were studied. Two different kinds of Y3+-ion releasing substances, Y2O3powder and Y(NO3)3, were used as coagulants and were introduced into stabilized alumina suspensions directly after dispersing. Compared with that of Y2O3powder, both the coagulation time and the added amount required for a reasonable shaping were significantly reduced for using Y(NO3)3as coagulant. The effects of the two coagulants on the properties of the consolidated green bodies and sintered ceramics were studied. The mechanisms of coagulation induced by the addition of Y3+-ions were discussed on the basis of interactions between Y3+ions and the added polyelectrolyte dispersant.

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