Gas Nitriding Mechanism in Titanium Powder Injection Molded Products

2007 ◽  
Vol 534-536 ◽  
pp. 361-364
Author(s):  
Toshiko Osada ◽  
Hideshi Miura ◽  
Takanobu Yamagami ◽  
Kazuaki Nishiyabu ◽  
Shigeo Tanaka
Keyword(s):  
Injection Molding ◽  
Nitrided Layer ◽  
High Reactivity ◽  
Metal Injection Molding ◽  
Powder Injection ◽  
Gas Nitriding ◽  
Process Gas ◽  
Metal Powder Injection Molding ◽  
Injection Molded ◽  
Nitriding Mechanism

Gas surface treatment is considered to be especially effective for Titanium because of its high reactivity. In this study, we investigated the gas nitriding mechanism in titanium sintered parts produced by metal powder injection molding (MIM) process. In MIM process, gas nitriding can be surface-treated subsequently after debinding and sintering process. Then, the microstructure and nitrogen content of sintered MIM parts are considered to be greatly influenced by not only nitriding conditions but also sintered conditions. In this study, the effects of sintering time on microstructure such as nitrided layer thickness and hardness was investigated. Focus was given to the effects of specimen size on nitriding process, because the size of micro metal injection molding (μ-MIM) product is so small and the specific surface of that product is so large that the mechanical and functional properties can be subject to change by nitriding.

Gas Nitriding Mechanism in Titanium Powder Injection Molded Products

2007 ◽  
pp. 361-364
Author(s):  
Toshiko Osada ◽  
Hideshi Miura ◽  
Takanobu Yamagami ◽  
Kazuaki Nishiyabu ◽  
Shigeo Tanaka
Keyword(s):  
Titanium Powder ◽  
Powder Injection ◽  
Gas Nitriding ◽  
Injection Molded ◽  
Nitriding Mechanism

An easy-to-decompose binder for Ti metal injection molding: Preparation and characterization of feedstock

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540005 ◽  
Author(s):  
Muhammad Dilawer Hayat ◽  
Guian Wen ◽  
Peng Cao
Keyword(s):  
Injection Molding ◽  
Decomposition Temperature ◽  
Metal Injection Molding ◽  
Powder Injection ◽  
Solid Loading ◽  
Carbon And Nitrogen ◽  
Impurity Control ◽  
Metal Powder Injection Molding ◽  
Interstitial Elements

Impurity control is crucial to Ti metal powder injection molding (Ti-MIM) since titanium is a universal solvent to interstitial elements such as oxygen, carbon and nitrogen. In this study, a low decomposition temperature binder system was developed; the rheological and solvent debinding assessments of the feedstock formulated from this binder were performed. Solvent mixing was employed to prepare homogeneous feedstocks. Effects of powder shape and solid loading on rheological properties were evaluated. After injection molding, a debinding profile was constructed. The debound parts were then characterized by microstructural observation.

Microstructure, Hardness, and Wear Resistance of Powder-Injection-Molded Products of Fe-Based Metamorphic Powders

2007 ◽  
Vol 26-28 ◽  
pp. 355-358
Author(s):  
Chang Kyu Kim ◽  
Chang Young Son ◽  
Dae Jin Ha ◽  
Tae Sik Yoon ◽  
Sung Hak Lee
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Injection Molding ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Thermally Stable ◽  
Austenitic Matrix ◽  
Amorphous Phases ◽  
Injection Molded

Powder injection molding (PIM) process was applied to Fe-based metamorphic alloy powders, and microstructure, hardness, and wear resistance of the PIM products were analyzed and compared with those of conventional PIM stainless steel products. When Fe-based metamorphic powders were injection-molded and then sintered at 1200 oC, completely densified products with almost no pores were obtained. They contained 34 vol.% of (Cr,Fe)2B borides dispersed in the austenitic matrix without amorphous phases. Since these (Cr,Fe)2B borides were very hard and thermally stable, hardness, and wear resistance of the PIM products of Fe-based metamorphic powders were twice as high as those of conventional PIM stainless steel products. Such property improvement suggested new applicability of the PIM products of Fe-based metamorphic powders to structures and parts requiring excellent mechanical properties.

Direct Sinter Bonding of Metal Injection-Molded Parts to Solid Substrate Through Use of Deformable Surface Microfeatures

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Thomas Martens ◽  
M. Laine Mears
Keyword(s):  
Injection Molding ◽  
Solid Substrate ◽  
Metal Injection Molding ◽  
Full Density ◽  
Metal Powders ◽  
Molded Parts ◽  
Primary Obstacle ◽  
Injection Molded ◽  
Sinter Bonding ◽  
Micro Features

In the metal injection molding (MIM) process, fine metal powders are mixed with a binder and injected into molds, similar to plastic injection molding. After molding, the binder is removed from the part, and the compact is sintered to almost full density. Though able to create high-density parts of excellent dimensional control and surface finish, the MIM process is restricted in the size of part that can be produced, due to gravitational deformation during high-temperature sintering and maximum thickness requirements to remove the binding agents in the green state. Larger parts could be made by bonding the green parts to a substrate during sintering; however, a primary obstacle to this approach lies in the sinter shrinkage of the MIM part, which can be up to 20%, meaning that the MIM part shrinks during sintering, while the conventional substrate maintains its dimensions. This behavior would typically inhibit bonding and/or cause cracking and deformation of the MIM part. In this work, we present a structure of micro features molded onto the surface of the MIM part, which bonds, deforms, and allows for shrinkage while bonding to the substrate. The micro features tolerate plastic deformation to permit the shrinkage without causing cracks after the initial bonds are established. In a first series of tests, bond strengths of up to 80% of that of resistance welds have been achieved. This paper describes how the authors developed their proposed method of sinter bonding and how they accomplished effective sinter bonds between MIM parts and solid substrates.

scholarly journals The Effect of the Holding Pressure Profile on the Metal Injection Molded Component Dimensions after Sintering

2020 ◽  
Vol 14 (4) ◽  
pp. 423-427
Author(s):  
Emir Šarić ◽  
Samir Butković ◽  
Muhamed Mehmedović
Keyword(s):  
Injection Molding ◽  
Coordinate Measuring Machine ◽  
Volumetric Flow Rate ◽  
Pressure Profile ◽  
Metal Injection Molding ◽  
Injection Velocity ◽  
Outer Diameter ◽  
N2 Atmosphere ◽  
Measuring Machine ◽  
Injection Molded

The volumetric flow rate (injection velocity) and the holding pressure are metal injection molding (MIM) parameters that have a strong influence on the green parts density and density homogeneity, but their effect on sintered dimensions after sintering is still to a large extent unexplored. To reveal the relationship between the injection molding parameters and sintered dimensions, ring-shaped components were injection molded by using different values of injection velocities in combination with a rump-down and rumpup holding pressure profile. Afterwards, the green components were catalytically debound and sintered in the nitrogen (N2) atmosphere. Finally, the component dimensions: the height, inner and outer diameter were measured by using a coordinate measuring machine. The ready-to-mold granules Catamold 310N made of heat resistant stainless steel X40CrNiSi 25-20 (according to the EN standard) powder and polyacetal based binder were used. The results showed that the interaction between the injection velocity and the holding pressure profile can be used to systematically adjust shrinkage after sintering. This approach is based on the dependence of the binder crystallization temperature on pressure, when the powder/binder proportion changes with the injection velocity.

The Study and Application of Metal Injection Molding of Fe-Ni-Co Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 590-594
Author(s):  
Chi Zhang ◽  
Rong Xiang ◽  
Jing Luo
Keyword(s):  
Injection Molding ◽  
Expansion Coefficient ◽  
Electronic Packaging ◽  
Production Efficiency ◽  
Semiconductor Industry ◽  
Ceramic Powder ◽  
Production Costs ◽  
Metal Injection Molding ◽  
Powder Injection ◽  
Structure Stability

Packaging material of electronic goods requires higher strength, higher reliability, and lower expansion coefficient .What’s more, forming process is important. The Fe-Ni-Co alloy has a low expansion coefficient and good structure stability, so it is often used for packaging materials for the semiconductor industry. The shape of electronic packaging parts is so complex that the traditional manufacturing processes are difficult to form and it costs more, which greatly limits the application of Fe-Ni-Co alloy in complex electronic packaging parts. Metal (ceramic) powder injection molding (MIM / CIM) is a new near net shape technology. In this paper, we analyze the structures and characteristics of Gehause which is an electronic packaging box that has been successfully used in the MIM process to produce it. In this process, we adopted a new material of Fe-Ni-Co alloy, a specia binder and SPC (Statistical Process Control) technology which control parameters of injection molding and weight of parts. After sintering, the mechanical properties and precision of finished products meet all demands. Therefore, MIM technology can greatly improve the production efficiency, save materials and reduce production costs in producing Gehause.

Innovative Metal Injection Molding (MIM) Method for Producing CoCrMo Alloy Metallic Prosthesis for Orthopedic Applications

2014 ◽  
Vol 879 ◽  
pp. 102-106
Author(s):  
Noorsyakirah Abdullah ◽  
Mohd Afian Omar ◽  
Shamsul Baharin Jamaludin ◽  
Nurazilah Mohd Zainon ◽  
Norazlan Roslani ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Injection Molding ◽  
High Performance ◽  
Slip Casting ◽  
Plastic Injection Molding ◽  
Metal Injection Molding ◽  
Powder Injection ◽  
Powder Metallurgy Process ◽  
The Cost ◽  
Plastic Injection

Powder injection molding (PIM) is a powder metallurgy process currently used for the production of complicated and near net shape parts of high performance materials [. This technique basically combines the advantages of plastic injection molding and the versatility of the conventional powder metallurgy technique. The process overcomes the shape limitation of powder compaction, the cost of machining, the productivity limits of isostatic pressing and slip casting, and the defect and tolerance limitations of conventional casting [1, 2, . According to German and Bose [, the technology of metal injection molding (MIM) is more complicated than that of the plastic injection molding, which arises from the need to remove the binder and to densify and strengthen the part. The process composed of four sequential steps: mixing of the powder and organic binder, injection molding, debinding where all binders are removed and sintering [1, 2, 3, 4]. If it necessary, secondary operations such as heat treatments after sintering can be performed [1, 2, 3, 4, .

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