Effects of heating rate in thermal debinding on the microstructure and property of sintered NiCuZn ferrite prepared by powder injection molding

Author(s):  
Jinhui Gu ◽  
Liang Qiao ◽  
Wei Cai ◽  
Jingwu Zheng ◽  
Yao Ying ◽  
...  
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 ◽  
...  

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 ◽  
...  

2016 ◽  
Vol 1133 ◽  
pp. 90-94
Author(s):  
Muhammad Rafi Raza ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhammad ◽  
Majid Niaz Akhtar ◽  
Javad Rajabi

Powder injection molding (PIM) process is suitable for both metal and ceramic materials to produce parts with high volume and accuracy at low cost. In this research work, 90wt. % of Ti6Al4V was dry mixed with 10wt. % of Hydroxyapatite (HA). The resultant mixture was further mixed with different space holders in weight ratio 8:2. The feedstock was prepared by mixing the final mixed powder with PEG and PW based binder systems. The dumbbell shape parts were produced using DSM Xplore injection molding machine. The molded samples were debound into two stages i.e solvent extraction followed by thermal debinding. The debinding parameters were optimized for different binder with space holders. The major binders’ paraffin wax (PW) extracted in haptane and PEG in water immersion at temperatures of 60 °C and 50 °C for 5 hrs respectively. The thermal de-binding was performed successfully at 500 °C by varying the heating rate from 3 °C/min-5 °C/min with holding time 1hr in argon atmosphere followed by the sintering in vacuum. During molding short shot defects and cracks were observed while during debinding, collection of binder, swelling and holes were noted. These types of defects may be due to space holder, improper binder, heating rate, temperature and dwell time at each processing step. The sintered test specimens were analyzed for porosity and microstructure. The results showed that the PEG based binder system with NaCl space holder is more effective to produce porous Ti/HA composite through PIM. Porous Ti/HA composite showed interconnected pores with average size of 90µm.


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.


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.


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