Ⅰ型拉伸试样金属注射成形多相流动的三维数值模拟

3D Multi-phase Flow Numerical Simulation of Die Filling Process for Metal Injection Molding Ⅰ-type Tensile Test Specimen

将粉末注射成形充模过程视为粘结剂、粉末和空气的三相流动过程,基于多相流理论给出金属注射成形的多相流动控制方程.根据金属注射成形的工艺特点确定多相流动控制方程的初边界条件,用多相流数值分析软件CFX对Ⅰ型拉伸试样的铁粉注射成形充模流动过程实现了三维数值模拟,分析了模腔中不同位置处粘结剂-粉末流动的速度曲线.数值模拟结果表明在I型拉伸试样金属注射成形充模流动过程中发生过两相分离的现象,数值模拟的瞬态信息可用于金属注射成形产品缺陷的分析与控制.

The filling process of metal injection molding（MIM） is regarded as a three - phase flow process consisting of binder, powder and air phases in this paper. The multi-phase governing equations of MIM are given depended on multi - phase flow theory and the initial and boundary conditions of the equations are determined according to the in- dustrial characteristic. Based on CFX software, the three dimension numerical simulation of die filling process for iron powder injection moldingⅠ- type tensile test specimen is established, and the velocity curves of binder and powder in different positions are analyzed. The numerical simulation results show that there is twophase separation phenomenon during the whole filling process of Ⅰ -type tensile test specimen metal injection molding, and the numerical simulation transient information could be used for analyzing and controlling the products＇ drawback of metal injection molding.