大长径比超细WC-Co圆棒PIM充模过程的数值模拟  

Numerical Simulation of PIM Filling Process of Ultra-Fine WC-Co Round Bar with Large Aspect Ratio

作　　者：谢兴铖 曹瑞军 李增德 周增林 李卿 李悦[2] 贾斌 Xie Xingcheng;Cao Ruijun;Li Zengde;Zhou Zenglin;Li Qing;Li Yue;Jia Bin(GRIMAT Engineering Institute Co.,Ltd,Beijing 101407,China;The 29th Research Institute of CETC,Chengdu 610036,China)

机构地区：[1]有研工程技术研究院有限公司,北京101407 [2]中国电子科技集团公司第二十九研究所,四川成都610036

出　　处：《稀有金属材料与工程》2021年第1期160-166,共7页Rare Metal Materials and Engineering

基　　金：国家重点研发计划专项(2017YFB0306000);有研科技集团有限公司青年基金(66271907);有研科技集团有限公司科技创新基金天使研究项目(2019TS0102)。

摘　　要：基于计算流体动力学的粉末-粘结剂双流体模型,采用CFX商业软件对大长径比超细WC/10Co粉末注射成形(PIM)充模过程进行数值模拟。结果表明:数值模拟结果与实际充模过程相一致,其假设条件和参数设置具有合理性,双流体模型具有可行性;粉末与粘结剂的温度分布一致,喂料熔体最低温度(≥330 K)高于粘结剂的玻璃化温度,不发生凝固现象;粉末的粘度为50.0~379.4 Pa·s,粘结剂的粘度为2.9~9.2 Pa·s,粘度差是造成偏析现象的主要原因;从浇口处到模壁处,粉末与粘结剂的相对速度差从0.2%增加到1.8%,从浇口处到远端,相对速度差从0.1%增大到1.6%,相对速度差是引起偏析现象的主要原因。Based on the powder-binder two-fluid model,the filling process was simulated by CFX commercial software,especially for the ultra-fine WC/10Co round bar with large aspect ratio by powder injection molding(PIM).The results indicate that the numerical simulation results are almost consistent with the experimental filling process results,which proves that the hypothesis and parameter settings are reasonable and the two-fluid model is feasible.Also there is no great difference in temperature distribution between powder and binder.There is no solidification for melting feedstock,because the lowest temperature at 330 K of melting feedstock is higher than the vitrification temperature of binder.In addition,the great difference in the viscosity between powder and binder,which is 50.0~379.4 and 2.9~9.2 Pa·s,respectively,is one reason for segregation.Finally,another main reason for segregation is the relative difference of velocity between powder and binder,which increases remarkably,for example,the velocity from gate to the die wall changes from 0.2%to 1.8%,and velocity from gate to the for end changes from 0.1%to 1.6%.

关 键 词：双流体模型 超细WC/10Co 充模过程 数值模拟 

分 类 号：TF125.3[冶金工程—粉末冶金]