镁基非晶复合材料的制备与性能研究-材料加工工程专业毕业论文.docxVIP

郑州大学硕士学位论文全非晶态结构变为非晶基体加既析出晶体相。Mg基金属玻璃复合材料 郑州大学硕士学位论文 全非晶态结构变为非晶基体加既析出晶体相。Mg基金属玻璃复合材料 (M965Cu2sGdlo)lo嘛Ti。(x=O，2．5，5，7．5)的DSC分析结果表明：在玻璃转变 阶段，随着X的增大，晶化放热峰由两个增加到三个，而且趋势越来越明显；在 熔化阶段，熔化峰也随着合金中n含量的增加由单一的吸热峰演变成两个高低 不等的吸热峰。分析表明，合金在快冷过程中，Mg基固溶体作为竞争领先相首 先从液相中析出，此时的液相成分具有较高的非晶形成能力，在一定的冷却速度 下，金属间化合物的析出受到抑制，剩余的液相转变为非晶态组织。加入钛后的 镁基金属玻璃复合材料同不加钛时的合金相比，断裂强度和塑性变形能力都有了 不同程度的提高，塑性变形中也出现了明显的加工硬化现象。尤其是 (M965Cu25Gdlo)1舡5n5金属玻璃复合材料的压缩强度达到977MPa，塑性变形能力 也达到了0．5％。 关键词：金属玻璃； 复合材料； 镁； 玻璃形成能力； 力学行为 Ⅱ 郑州大学硕士学位论文 郑州大学硕士学位论文 ABSTRACT ABSTRACT Magnesium-based amorphous alloys have attracted considerable attention due to fight-weight,high-strength and a good bulk glass forming ability(OFA)．However,the applications have been limited because the Mg—based bull【metallic glass(BMG、 5UlCerS from low ductility problems．In this work,it was demonstrated that a composite design strategy to achieve bulk metallic glass based light-weight Mg flloys． Carbon nanotubes(CNTs)，Co，Ti were added into the M96sCu2sGdl0 bulk metallic glass forming alloys to form the bulk metallic glass composites．The cross-sectional SILrfjaces of the硒-cast rods were examined using X-my diffraction(Ⅺ①)．The thermal stability of the glass and composites Was investigated using differential scanning calorineter(Dsc)．Mechanical behavior in uiaxiai compression of these composites Was measured using universal material testing machine．The main results arc follwed： 1．M965Cu2sGdlo metallic glass、^，ith diameter of 2mm and 3mm and its CNTs reinforced composites with diameter of 2mm were achieved by means of the copper mould casting．It was shown that carbon nanombe phase existed in Mg—based glass matrix．The apparent active energy of Mg—based bulk glass and its amorphous composites were 139 KJ／mol and 154 KJ／tool，respectively,using thermal stability measurement and analysing．crystalline rate constant is O．582 s．1．It Was uncovered that addition of CNT