Ultrafine Grain Tungsten Heavy Alloys with Excellent Performance Prepared by Spark Plasma Sintering
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2020年第2期
论文作者：张金刚 王为民 季伟 HE Qianglong WANG Aiyang TAN Lin YANG Kai
文章页码：393 - 398
摘 要：Ultrafine grain tungsten heavy alloys （WHAs） were successfully produced from the nano-crystalline powders using spark plasma sintering.The present study mainly discussed the effects of sintering temperature on the density,microstructure and mechanical properties of the alloys.The relative density of 98.12% was obtained at 1 050 ℃,and the tungsten grain size is about 871 nm.At 1 000 ℃-1 200 ℃,the mechanical properties of the alloys tend to first rise and then goes down.After SPS,the alloy exhibits improved hardness （84.3 HRA at 1 050 ℃） and bending strength （987.16 MPa at 1 100 ℃）,due to the ultrafine-grained microstructure.The fracture mode after bending tests is mainly characterized as intergranular or intragranular fracture of W grains,interfacial debonding of W grains-binding phase and ductile tearing of binding phase.The EDS analysis reveals a certain proportion of solid solution between W and Ni-Fe binding phase.The good mechanical properties of the alloys can be attributed to grain refinement and solid solution strengthening.
张金刚，王为民，季伟，HE Qianglong，WANG Aiyang，TAN Lin，YANG Kai
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Institute of Material Science and Engineering,Wuhan University of Technology
摘 要：Ultrafine grain tungsten heavy alloys （WHAs） were successfully produced from the nano-crystalline powders using spark plasma sintering.The present study mainly discussed the effects of sintering temperature on the density,microstructure and mechanical properties of the alloys.The relative density of 98.12% was obtained at 1 050 ℃,and the tungsten grain size is about 871 nm.At 1 000 ℃-1 200 ℃,the mechanical properties of the alloys tend to first rise and then goes down.After SPS,the alloy exhibits improved hardness （84.3 HRA at 1 050 ℃） and bending strength （987.16 MPa at 1 100 ℃）,due to the ultrafine-grained microstructure.The fracture mode after bending tests is mainly characterized as intergranular or intragranular fracture of W grains,interfacial debonding of W grains-binding phase and ductile tearing of binding phase.The EDS analysis reveals a certain proportion of solid solution between W and Ni-Fe binding phase.The good mechanical properties of the alloys can be attributed to grain refinement and solid solution strengthening.
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