【作者】 康彦；

【导师】 唐文亭； 袁森；

【作者基本信息】 西安理工大学 ， 材料加工工程， 2006， 硕士

【摘要】 为了使SIMA法制备半固态镁合金浆料的组织细化、分布均匀，同时保持铸态镁合金直接加热制备半固态成形所需浆料的工业化途径，本文设计改装了一套半固态镁合金辅助搅拌装置，并进行了改善镁合金半固态组织的实验。在SIMA法二次半固态加热过程中和铸态AZ91镁合金直接半固态等温过程中实施机械搅拌，研究了搅拌速度、搅拌时间、等温温度参数对搅拌效果的影响作用，分析了经过搅拌后的半固态合金组织特点。 结果表明： 自行设计、改制的半固态镁合金辅助搅拌装置，构造简单，搅拌效果好，能够实现对半固态镁合金搅拌过程中的主要工艺因素进行控制。对镁合金在半固态温度下实施辅助搅拌，可使采用SIMA法制备半固态浆料的α固相晶粒更加细小、均匀圆整，同时缩短树枝晶向近球状晶演化的时间，有利于半固态组织的均匀化。对铸态AZ91镁合金在半固态温度实施搅拌可大大缩短树枝晶向球状晶演化所需的等温时间，为铸态合金直接加热制备半固态浆料的工业化应用提供了参考依据。 在半固态镁合金搅拌过程中，搅拌时间，搅拌速度，等温温度是影响搅拌效果的三个主要因素。在本文的试验条件下，对SIMA法制备半固态浆料优选的工艺参数分别为：半固态等温温度580℃，搅拌时间6min～8min，搅拌速度800r／min。对铸态AZ91镁合金直接加热制备半固态浆料优选的工艺参数分别为：半固态等温温度570℃，搅拌时间8min～10min，搅拌速度800r／min。更多还原

【Abstract】 In order to make semi-solid magnesium alloy microstructure refine and distributing uniformity,a subsidiary stirring device was designed and rebuilt by that the industrialized way of heating as-cast magnesium alloy directly to prepare semi-solid forming slurry.The experiment for improving semi-solid microstructure have been done by this device.Based on the experiment of stirring in the reheating process of semi-solid magnesium alloy and in the isothermal process of as-cast magnesium alloy,the influence of stirring speed,stirring time,isothermal temperature parameter to stirring effect was studied.At last,the characters of semi-solid microstructure of magnesium alloy was analysed in this paper.The main results and conclusions of this paper show:A subsidiary stirring device is self-designed and rebuilt,which holds the characteristics of simple constitution,mechanism stability and reasonable control,by which main factors in the stirring process can be controlled.After stirring the compressed Mg alloy,α phase of semi-solid slurry becomes finer and uniform,and the time of changing from dendries to spheric grain can be shorted. After stirring about uncompressed Mg alloy,the time can be shorted greatly. Those results give some references to industry application of perapering semi-solid slurry by this method.Stiring time,stirring speed and isothermal temperature are the three main factors that influence the stirring result in the process. On this experimental condition,the optimum parameters for preparing semi-solid slurry with SIMA are isothermal temperature(580℃),stiring time (6min～8min),stirring speed (800r/min),and for preparing semi-solid slurry with derictly heat on casting AZ91 are isothermal temperature(570℃),stiring time (8min～10min),stirring speed (800r/min).更多还原