超细晶不锈钢/TiC复合材料的电化学腐蚀行为

采用Gleeble-1500热/力模拟试验机进行压缩试验,研究了Mg-6Zn-1Mn合金在变形温度250～450℃、应变速率0.001～10 s-1范围内的流变应力行为,采用Zener-Hollomon参数法构建合金高温塑性变形的本构关系；并以热压缩试验为基础,建立并初步分析了Mg-6Zn-1Mn合金的DMM加工图.结果表明:Mg-6Zn-1Mn合金在热压缩过程中发生了明显的动态回复与动态再结晶,流变应力随应变速率的增加而增加,随温度的升高而降低；流变应力的预测值与试验值较吻合；建立的加工图表明合金高温变形时存在2个失稳区域,而在温度325～425℃、应变速率0.01～0.365 s-1范围内出现1个非失稳区、功率耗散峰值区,该区域最适合Mg-6Zn-1Mn合金进行热加工.

Electrochemical Corrosion Behavior of Ultrafine Grained Stainless Steel/TiC Composite Materials

Hot deformation behavior and processing parameters of the cast Mg-6Zn-1Mn alloy were investigated. The uniaxial compression tests on Gleeble-1500 thermal simulation test machine were conducted at the temperature ranging from 250 to 450 oC and strain rate ranging from 0.01 to 10 s-1. The constitutive equation of the plastic deformation of Mg-6Zn-1Mn alloy at elevated temperatures was obtained by introducing Zener-Hollmon parameter. According to the experimental results, the hot processing map based on the dynamic materials modeling was drawn. The results show that the dynamic recover and dynamic recrystallization occur obviously during hot compression of Mg-6Zn-1Mn alloy. The flow stress increases with the increase of strain rate and decreases with the increase of temperature. The flow stress of Mg-6Zn-1Mn alloy predicted by the proposed models well agrees with experimental results. The obtained processing map presents two unsteady zones while a steady zone with peak efficiency of power dissipation occurs in the temperature range of 325~425 oC and the strain rate range of 0.01~0.365 s-1 which is the most favorite deformation domain.