退火温度对FeMoCrVTiSix高熵合金组织及力学性能的影响

在400、600、800、1100 ℃下对FeMoCrVTiSi_x(x=0、0.3)进行退火处理,利用X射线衍射仪、扫描电镜、差热扫描分析仪、显微硬度计、万能试验机等探究了不同退火温度对合金的组织和力学性能的影响。结果表明,Si元素的添加提高了FeMoCrVTi高熵合金的热稳定性。经过退火处理,FeMoCrVTiSi_x高熵合金的微观组织仍为以BCC固溶相为主的枝晶结构,但在枝晶边缘出现黑色的细小富Ti相,其含量随着退火温度的增加而增多,在1100 ℃下富Ti相回溶。富Ti相的析出提高了合金的硬度,其中,800 ℃退火后试样的硬度达到最大值,FeMoCrVTi试样的硬度达到932 HV0.2,FeMoCrVTiSi_0.3的硬度达到998 HV0.2。

Effect of annealing temperature on microstructure and mechanical properties of FeMoCrVTiSix high entropy alloy

Effect of different annealing temperatures (400, 600, 800, 1100 ℃) on the microstructure and mechanical properties of FeMoCrVTiSi_x(x=0, 0.3) alloy was studied by using X-ray diffractometer(XRD), scanning electron microscope(SEM), differential thermal scanning analyzer(DSC), microhardness tester and universal material testing machine. The results show that the addition of Si improves the thermal stability of the FeMoCrVTi high entropy alloy. After annealing treatment, the microstructure of FeMoCrVTiSi_x high entropy alloy is still mainly composed of BCC solid solution phase, but a black fine Ti-rich phase appears at the edge of the dendrite, and its content increases with the increase of annealing temperature until it re-dissolves at 1100 ℃. The precipitation of Ti-rich phase is conducive to the improvement of the hardness. The hardness of the specimen reaches the maximum value annealed at 800 ℃, with that of the FeMoCrVTi and FeMoCrVTiSi_0.3 alloys reaching 932 HV0.2 and 998 HV0.2, respectively.