Investigation of Deibinding and Sintering of 3Y-ZrO2 Gear Fabricated by Micro Powder Injection Molding

2013 ◽  
Vol 749 ◽  
pp. 378-386
Author(s):  
Lin Liu ◽  
Yu Chen ◽  
Xin Lei Ni ◽  
Hai Qin Yin ◽  
Xuan Hui Qu

The rapid development of micro-system and its related products has caused an upsurge of micro components, and the micro powder injection molding is potential for its mass production. In this work, the solvent debinding mechanism of the in-house feedstock was studied. The influence of solvent debinding, thermal debinding and sintering on the micro gears was investigated. The weight loss of 3Y-ZrO2 micro gears ranging from 200 to 900μm were compared by using six types of solvent including ether mixture withanhydrous alcohol, petroleum ether, chloroform and are hexane etc. The thermal debinding scheme was determined based on the DSC and TGA results of the binder system. The effect of the heating rate on the micro gears was investigated. The experimental results showed that the petroleum ether mixture with anhydrous alcohol yielded the best debinding effect for the micro gears, which was controlled by diffusion and dissolution. Using the established debinding and sintering schedule, the defect free micro gears were successfully fabricated.

2001 ◽  
Vol 16 (8) ◽  
pp. 2436-2451 ◽  
Author(s):  
Ying Shengjie ◽  
Y. C. Lam ◽  
S. C. M. Yu ◽  
K. C. Tam

Two-dimensional simulation of thermal debinding in powder injection molding based on mass and heat transfer in deformable porous media is proposed. The primary mechanisms of mass transport, i.e., liquid flow, gas flow, vapor diffusion, and convection, as well as the pyrolysis of polymers, and their interactions, are included in the model. The simulated results revealed that polymer removal process is primarily affected by liquid flow, which is mainly dominated by pressure-forced flow rather than capillary-driven flow. A significant phenomenon, enrichment with liquid polymer in the outer surface regions of the compact, is explained.


2017 ◽  
Vol 311 ◽  
pp. 357-363 ◽  
Author(s):  
Dongguo Lin ◽  
Daniel Sanetrnik ◽  
Hanlyun Cho ◽  
Seong Taek Chung ◽  
Young Sam Kwon ◽  
...  

2003 ◽  
Vol 437-438 ◽  
pp. 129-132
Author(s):  
Yee Cheong Lam ◽  
Ying Shengjie ◽  
K.H. Lam ◽  
Jan Ma ◽  
K.C. Tam ◽  
...  

2012 ◽  
Vol 706-709 ◽  
pp. 1948-1954
Author(s):  
Lin Liu ◽  
X.L. Ni ◽  
Hai Qing Yin ◽  
Xuan Hui Qu

Micro powder injection molding has been accepted as a potential forming technology for large-scale production of miniature components in industries. However, mold filling capability is often poor due to the blind hole structure of the die cavity, which restricts the widespread application of this technique. In this paper, ZrO2 micro gears with addendum circle ranging from 900μm to 200μm were studied. Instead of using traditional PW-HDPE-SA binder as in powder injection molding, thermoplastic binder system is optimized here for better replication of micro gear. It is found that the dimensional accuracy and demold after injection molding can be improved by utilizing proper binder system. ZrO2 feedstock with a powder loading of 46vol.% and the binder system consisting of BW, HDPE and SA was successfully injection molded and demolded, which indicates good mold filling capability and sufficient demolding strength. The binder system was successfully removed by debinding process in two steps, solvent debinding followed by thermal debinding. Debound components free of defects were obtained. Keywords: Micro powder injection molding, ZrO2 feedstock, Binder system, Molding filling capability, Demolding strength


2019 ◽  
Vol 45 (14) ◽  
pp. 16982-16991
Author(s):  
Chang Woo Gal ◽  
Joo Won Oh ◽  
Gi Woung Song ◽  
Da Seul Shin ◽  
Seong Jin Park

2007 ◽  
Vol 61 (3) ◽  
pp. 809-812 ◽  
Author(s):  
L. Liu ◽  
N.H. Loh ◽  
B.Y. Tay ◽  
S.B. Tor ◽  
Y. Murakoshi ◽  
...  

2015 ◽  
Vol 87 ◽  
pp. 386-392 ◽  
Author(s):  
Muhammad Rafi Raza ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Majid Niaz Akhtar ◽  
Javad Rajabi

2005 ◽  
Vol 475-479 ◽  
pp. 2143-2146
Author(s):  
Hai Qing Yin ◽  
Cheng Chang Jia ◽  
Xuan Hui Qu

Manufacture of 2:17 Sm-Co magnets by powder injection molding was investigated. The binder of thermoplastic polymer was selected as the wax-based system including paraffin wax, stearic acid and high density polyethylene. Before mixing with paraffin wax and high density polyethylene, the powder of 5-8 µm was coated by stearic acid. The molding compacts were obtained under 200°C without deficits. Solvent debinding and thermal debinding were combined to remove the binder. The basic magnetic characteristics of the specimen were of the same level as those by powder metallurgy technique, which indicated that to fabricate 2:17 Sm-Co magnets by powder injection molding was feasible.


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