【摘要】 采用机械合金化+热压工艺路线来制备化学配比成分的单相Laves相NbCr2合金。研究了Cr,Nb元素粉经20h球磨后在1200℃,1250℃和1300℃不同时间热压所获得的Laves相NbCr2合金的组织和性能。结果表明:1250℃×0.5h热压获得的Laves相NbCr2合金组织均匀,晶粒尺寸达到微/纳米级,致密度达到97.1%,室温断裂韧性高于5.07MPa.m1/2。与熔铸工艺制备的单相Laves相NbCr2合金的断裂韧性1.50MPa.m1/2相比,所制备的单相Laves相NbCr2合金的室温断裂韧性大大提高,充分实现了细晶韧化的效果。更多还原

【Abstract】 Laves phase NbCr2 alloys with a stoichiometric composition were prepared by mechanical alloying followed by hot pressing.Microstructures and properties were investigated on Laves phase NbCr2 alloys prepared from 20h mechanically alloyed powders of elemental chromium and niobium powders by hot pressing at 1200℃,1250℃ and 1300℃ for different time.The results indicate that Laves phase NbCr2 alloy with homogeneous microstructure and micro-and/or nano-grains is obtained by hot pressing at 1250℃ for 0.5h,moreover,the alloy has a relative density of 97.1% and a room temperature fracture toughness more than 5.07MPa m1/2.Compared with Laves phase NbCr2 alloy with a fracture toughness of 1.50MPa m1/2 prepared by arc-melting,the fracture toughness of Laves phase NbCr2 alloy prepared here increases greatly,the effect of fine grain toughening has been fully realized.更多还原