掺杂Y_(2)O_(3)钨基复合材料在近韧脆转变温区的静载拉伸特性

Static Tensile Properties near Ductile-Brittle Transition Temperature Region of W-based Composites Doped with Y_(2)O_(3)

制备了掺杂质量分数分别为0.5%,2.0%Y_(2)O_(3)的钨基复合材料,研究了其显微组织,通过不同温度(25~800℃)下的拉伸试验分析了其近韧脆转变温区的变形特性。结果表明:2种复合材料均存在由轧制变形导致的大量位错,Y_(2)O_(3)颗粒对位错运动起到钉扎作用;Y_(2)O_(3)掺杂质量分数为2.0%的复合材料的晶粒更细小,发生韧脆转变的温度更低,在300~400℃拉伸时发生半脆性行为,断口区域位错密度在3.8×10^(15)~3.9×10^(15)m^(-2),在600~800℃下发生明显塑性变形,位错密度增加至6.2×10^(15)~6.8×10^(15)m^(-2)。

W-based composites doped with 0.5wt%and 2.0wt%Y_(2)O_(3)were prepared.The microstructure of the composites was investigated.The deformation characteristics near ductile-brittle transition temperature region of the composites were analyzed by tensile tests at different temperatures(25-800℃).The results show that the two composites had a large number of dislocations formed by rolling deformation,and Y_(2)O_(3)particles played a pinning role in dislocation motion.The composite containing 2.0wt%Y_(2)O_(3)had smaller grain size and a lower ductile-brittle transition temperature.The semi-brittle behavior of the composite containing 2.0wt%Y_(2)O_(3)occurred during tension at 300-400℃,and the dislocation density in the fracture area was between 3.8×10^(15)-3.9×10^(15) m^(-2);during tension at 600-800℃,plastic deformation occurred,and the dislocation density increased to 6.2×10^(15)-6.8×10^(15) m^(-2).