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| Study on Concentrating Behavior of Binder on Surface of Ti(C,N)/AlCoCrFeNi Cermets During Sintering |
| ZHU Gang1, CHEN Jialin1, JIA Hailong1, LIU Ying2, XIE Ming1
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1 State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute of Precious Metals, Kunming 650106;
2 School of Materials Science and Engineering, Sichuan University, Chengdu 610044 |
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Abstract Through the analysis of surface topography and phase composition of the alloy, the concentrating behavior of binder on the surface of Ti(C,N)/AlCoCrFeNi cermets during sintering process were studied. The results indicated that the binder was obviously concentrated on surface when sintered under 1 300 ℃ for 60 minutes, and formed a third phase containing M6C-type brittle phase (η). This phenomenon could attribute to the carbon concentration difference, solid solution concentration difference and temperature difference of the surface and interior, which caused by decarbonization during sintering. It urged the migration of W, Ta, Ti, Mo to the interior in a diffusion way. Besides, the surface decarbonization also caused the increase of alloy eutectic temperature. Thus, the reduction of surface liquid phase leaded to the generation of negative pressure, which made the inner liquid phase transfer to the surface. In addition, binding phase regions with different volume content in the microstructure might lead to the pressure difference, and the rich W region was apt to migrate to the poor W region with low liquid phase during sintering, which caused the binding phase transfer, permeate and finally gathered on the surface.
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Published: 25 August 2017
Online: 2018-05-07
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2017, Vol. 31 
