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

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.

2007 ◽  
Vol 534-536 ◽  
pp. 361-364
Author(s):  
Toshiko Osada ◽  
Hideshi Miura ◽  
Takanobu Yamagami ◽  
Kazuaki Nishiyabu ◽  
Shigeo Tanaka

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.


2011 ◽  
Vol 383-390 ◽  
pp. 3234-3240 ◽  
Author(s):  
Tapany Udomphol ◽  
Benchawan Inpanya ◽  
Nutthita Chuankrerkkul

Characterization of feedstocks for powder injection molding of SiCp-reinforced aluminium composite, as potential use for automotive and light-weight applications, has been studied in this research. Al-4.5 wt.% Cu powder, SiCp and polymeric binder were pre-mixed and compounded using a twin screw extruder at 170oC prior to powder injection molding at 170 oC. Effects of varied solid loadings at 52, 55 and 58% on green properties of the feedstocks have been investigated. Experimental results showed that compounding followed by powder injection molding allowed uniform distribution of SiCp surrounding the aluminium powder. It was found that higher solid loading improved bulk density while hardness values were observed to be similar. Molded specimens of 55% solid loading provided the optimum bend strength and strain at failure. Moreover, it was observed that the opposing abrasive property with angular shape of SiCp resulted in SiCp scratching effect, leading to irregular surface of aluminium powder after injection molding. This consequence and molding porosity were expected to be responsible for relatively low density of the molded specimens, giving the difficulty in molding at higher solid loading.


2018 ◽  
Vol 770 ◽  
pp. 189-194
Author(s):  
Dong Guo Lin ◽  
Jae Man Park ◽  
Tae Gon Kang ◽  
Seong Taek Chung ◽  
Young Sam Kwon ◽  
...  

In this work, powder injection molding (PIM) of Ti-6Al-4V alloy powder has been studied. Defect-free high performance Ti-6Al-4V parts with low carbon/oxygen contents have been successfully prepared by PIM. A pre-alloyed Ti-6Al-4V alloy powder and wax-polymer binder system have been mixed together to prepare the feedstock. In mixing stage, the solid loading percentage and mixing conditions have been optimized. Rheological and thermal debinding behaviors of prepared feedstock have been characterized and numerically expressed based on rheometry and thermal gravity experimental results. In addition, the injection molding process of Ti-6Al-4V parts has been numerically analyzed to optimize the injection molding conditions. Consequently, the defect-free Ti-6Al-4V parts with low carbon and oxygen contents have been successfully fabricated by PIM, which exhibits excellent physical and mechanical properties.


2011 ◽  
Vol 291-294 ◽  
pp. 590-594
Author(s):  
Chi Zhang ◽  
Rong Xiang ◽  
Jing Luo

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.


2014 ◽  
Vol 879 ◽  
pp. 102-106
Author(s):  
Noorsyakirah Abdullah ◽  
Mohd Afian Omar ◽  
Shamsul Baharin Jamaludin ◽  
Nurazilah Mohd Zainon ◽  
Norazlan Roslani ◽  
...  

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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