MICROSTRUCTURE SIMULATION OF

Al-Si/SiCp COMPOSITES AND QUANTI-TATIVE

ASSESSMENT OF PARTICLE DISTRIBUTION

HOMOGENEITY

LI Bin¹  XU Qingyan¹  LI Xudong²  LIU Baicheng¹

(1. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084；

2. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050 )

Abstract: To study particle segregation phenomena and predict the final performance of particle reinforced metal matrix composite, the microstructure of SiC particle reinforced Al-Si composite made by stir casting is simulated based on the experiment. Two-dimensional models under normal solidification condition including macro heat transfer, nucleation, equiaxed dendrite growth and particle pushing are established and composite microstructures are simulated by a modified cellular automaton method coupled with finite difference method. A simple method is applied for quantitatively analyzing the effects of different casting processes, particle volume fraction and cooling rate on composite microstructure and particle distribution from both experimental and simulated sides. The simulated results of particle distribution and microstructures of composite are in agreement with the experimental results.

Key words: Metal matrix composite Particle pushing Microstructure Numerical simulation Quantitative assessment

CLC No: TG244.3

国家重点基础研究发展计划(973计划,   2005CB724105)和兰州理工大学甘肃省有色金属新材料重点实验室基金资助项目. Received 20060312,  received in revised form 20060925