CAJ | 학술논문

采用自主研发的强制对流搅拌装置(FCR)，研究筒体温度、浇注温度和搅拌速度对A356铝合金半固态组织的影响规律，探讨半固态浆料制备过程中的凝固行为。结果表明：适当降低浇注温度、筒体温度和提高搅拌速度均有利于半固态浆料组织的改善，能够制备晶粒细小、圆整、分布均匀的半固态组织；当浇注温度为620~630℃、筒体温度为570~580℃、筒体转速为200 r/min以上时，均能获得理想的半固态浆料，其初生固相颗粒平均直径在80μm以下，形状因子在0.75以上；强制对流搅拌装置极大地改变了传统凝固条件下熔体依靠传导单向传热和扩散缓慢传质的状态，使熔体的温度场和成分场趋于一致，破坏了枝晶生长的条件，有利于获得较好的半固态组织。
채용자주연발적강제대류교반장치(FCR)，연구통체온도、요주온도화교반속도대A356려합금반고태조직적영향규률，탐토반고태장료제비과정중적응고행위。결과표명：괄당강저요주온도、통체온도화제고교반속도균유리우반고태장료조직적개선，능구제비정립세소、원정、분포균균적반고태조직；당요주온도위620~630℃、통체온도위570~580℃、통체전속위200 r/min이상시，균능획득이상적반고태장료，기초생고상과립평균직경재80μm이하，형상인자재0.75이상；강제대류교반장치겁대지개변료전통응고조건하용체의고전도단향전열화확산완만전질적상태，사용체적온도장화성분장추우일치，파배료지정생장적조건，유리우획득교호적반고태조직。
A356 aluminum alloy semisolid slurry was prepared by self-developed forced convection rheoforming machine (FCR). The effects of barrel temperature, pouring temperature and rotation speed on the microstructure of semisolid slurry were investigated. The solidification behavior of the semisolid slurry preparation was discussed. The results show that reducing the barrel temperature and pouring temperature and increasing the rotation speed appropriately are beneficial to obtain semisolid slurry with fine and spherical solid particles distributed in the matrix uniformly. The desirable semisolid slurry with average primary solid phase diameter of below 80μm and shape factor of above 0.75 can be obtained at pouring temperature of 620-630℃, barrel temperature of 570-580℃and rotation speed over 200 r/min. The FCR device can greatly change the situation that the melt relies on diffusion to transfer the heat and mass in traditional solidification conditions. It destroys the generation environment of dendrites. The temperature field and the composition of the melt are going uniformly, which will be advantage to obtain better semisolid microstructure.