Zr元素对TZM合金组织和性能的影响

Effect of Zr on Microstructure and Properties of TZM Alloys

采用粉末冶金法制备了不同Zr元素添加量的TZM合金,研究Zr元素的添加量对高温钼合金的显微组织和性能的影响,通过SEM观察了不同Zr元素添加量的合金显微组织;利用EDS对视场中具有特殊形态的物相进行能谱分析和化学成分分析;使用显微硬度测试仪测试了不同Zr元素添加量的合金在室温下的显微硬度,使用Gleeble-1500热模拟试验机测试了不同Zr元素添加量的合金在1300和1400℃时的应力应变曲线。通过显微组织观察发现TZM合金中存在大量的黑色块状第二相,经能谱测定为Ti和Zr的氧化物、单质,它们的存在能有效地阻碍位错的运动,产生强化效果,并在此基础上分析了TZM合金的组织和强化机制。比较了不同Zr添加量的TZM合金在室温下的显微硬度,分析了不同Zr元素添加量的合金在1300和1400℃的应力应变曲线。发现Zr的添加量在0.07%时试样的显微硬度最大,热模拟实验机的数据显示Zr的添加量在0.07%时TZM合金在1300和1400℃变形抗力都最大。

TZM alloys with different Zr doping were prepared by powder metallurgy to study the effect of Zr elements on the microstructure and properties of high temperature molybdenum alloys.The microstructure of TZM alloy was observed by SEM.The chemical composition was analyzed.Microhardness was tested at room temperature by the microhardness tester.Their stress-strain curves at temperature of 1300 and 1400 ℃ were tested on the Gleeble-1500 heat-hot temperature testing machine.It was found that there were a lot of second phase in the black block.Energy spectrum showed that they were oxides of Ti and Zr.Their presence could hinder the movement of dislocations,resulting in enhancement effects.On this basis,alloy microstructure and the strengthening mechanism of the TZM alloys were analyzed.The micro-hardness at room temperature of TZM alloys with different Zr doping amounts was comparative.Stress-strain curves of Zr added alloy at 1300 and 1400 ℃ were analyzed.It was found that the hardness reached maximum at the doping amount of 0.07.Thermal simulating test machine data displayed that the TZM alloy with 0.07 Zr addition at 1300 and 1400 ℃ had the greatest deformation resistance.