Cu-Zr-Al-Y块体非晶合金复相材料的力学性能

Mechanical Properties of Cu-Zr-Al-Y Bulk Metallic Glass Composites

利用铜模喷铸法和等温退火热处理,制备具有不同晶化程度的(Cu47Zr45Al)8)98.5Y1.5块体非晶基复相材料(BMGCs),研究了其显微组织与力学性能的关系。结果表明,随着退火温度增加,(Cu47Zr45Al)8)98.5Y1.5非晶基复相材料的晶化分数(Vf)上升,相转变进程为:非晶→非晶+Cu10Zr7→非晶+Cu10Zr7+AlCu2Zr+Al2Zr。晶化过程中结晶相的析出强化作用能明显提高合金的显微硬度,760K退火20min后合金最大硬度(HV)可达691。合金断裂强度随退火温度升高先增加后减小。680K等温退火后合金断裂强度达到最高,为1 950MPa。断口SEM显示随着热处理温度提高,非晶基复相材料断裂模式由韧-脆混合断裂模式向解理脆性断裂模式转变。试验结果表明,可以通过控制退火温度、退火时间等参数对Cu基块体非晶基复相材料的力学性能进行调控。

(Cu47Zr45Al)8)98.5Y1.5 bulk metallic glass composites(BMGCs)with different crystallinity were prepared by copper mold casting and isothermal annealing treatment,and the relationship between microstructures and mechanical properties were investigated.The results indicate that the crystallization volume fraction(Vf)is increased with annealing temperature increase.The process of phase transition is presented as follows:Am(amorphous state)→Am+Cu10Zr7→Am+Cu10Zr7+AlCu2Zr+Al2Zr.The precipitation strengthening effect largely improves the microhardness of the alloy,and the maximum value of 691 HV can be observed after annealing at 760 Kfor 20 min.The fracture strength of the alloy is increased firstly and then decreased with the increase of annealing temperature.The fracture strength of the alloy reaches the maximum value of 1 950 MPa after isothermal annealing at 680 K.SEM of fracture surfaces reveals a transition of fracture characteristics from the ductile-brittle mixed fracture mode to a cleavage brittle manner with further annealing.The experimental results show that the mechanical properties of Cu-based BMGCs can be controlled by adjusting annealing process parameters,such as annealing temperature and annealing time.