颗粒增强镁基复合材料的超声原位合成机制及组织性能研究

项目名称： 颗粒增强镁基复合材料的超声原位合成机制及组织性能研究

项目编号： No.51301006

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 王朝辉

作者单位： 北京工业大学

项目金额： 25万元

中文摘要： 原位法制备颗粒增强镁基复合材料是目前镁材料领域的研究热点之一。本项目针对Vapor-Liquid-Solid reaction（VLS）工艺制备原位AlN颗粒增强镁基复合材料时，存在的反应温度高、产率低且颗粒分散性差等问题，提出利用超声场促进AlN颗粒的原位合成、促进其在熔体中有效分散的研究思路。以Mg-Al系镁合金为基体，以N2为反应气体，设计超声强度、反应物配比、反应温度及时间等多因素正交试验制备复合材料。通过相分析、微观组织观察等实验研究和热动力学计算等理论分析，获得原位合成AlN颗粒的产率、体积分数、分布状态、形貌、粒径等影响因素和规律，系统地阐明超声场作用下镁熔体中AlN颗粒的原位合成机制和分散机制。通过研究复合材料的宏/微观力学性能及塑性变形过程中的力学行为，阐明AlN颗粒在复合材料中的强韧化机制。通过本项目研究，为新型原位法制备颗粒增强镁基复合材料提供理论基础和技术原型。

中文关键词： 原位合成；镁基复合材料；AlN颗粒；超声场；组织性能

英文摘要： The particles reinforced magnesium matrix composites via in-situ method are a hot research topic in the magnesium alloys fields. In this proposal, it is solved by promoting the in-situ synthesis and dispersion of the AlN particles in the molten magnesium alloy with ultrasonic field that the problems, such as high reaction temperature, low yield and poor dispersion of particles, during the fabricating process of in-situ AlN particles reinforced magnesium matrix composites by Vapor-Liquid-Solid reaction (VLS) method. With the matrix of Mg-Al alloy and the reaction of N2, the composites are fabricated by orthogonal experiments with multi-factor, such as ultrasonic intensity, the ratio of reactants, temperature and time of reaction. The influencing factors and rules on yield, volume fraction, dispersion, morphology and particle size of AlN particles are obtained by phase analysis, microstructure observation and thermodynamic calculation. So the mechanism of in-situ synthesis and dispersion of the AlN particles in the molten magnesium alloy are explained scientifically. The macro/micro mechanical properties and mechanical behavior during plastic deformation of the composites are analyzed. Then the strengthening and toughening mechanism of the in-situ AlN particles in the magnesium matrix composites is expounded. Thro

英文关键词： In-situ synthesis；Magnesium matrix composites；AlN particles；Ultrasonic field；Microstructure and mechanical properties