Effects of annealing on microstructure, mechanical and electrical properties of AlCrCuFeMnTi high entropy alloy

The multi-component A1CrCuFeMnTi high entropy alloy was prepared using a vacuum arc melting process. Serial annealing processes were subsequently performed at 590 ℃, 750 ℃, 955 ℃ and 1 100 ℃ respectively with a holding time of 4 h at each temperature. The effects of annealing on microstructure, mechanical and electrical properties of as-cast alloy were investigated by using differential thermal analysis （DTA）, X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The experimental results show that two C14 hexagonal structures remain unchanged after annealing the as-cast A1CrCuFeMnTi alloy specimens being heated to 1 100℃. Both annealed and as-cast microstructures show typical cast-dendrite morphology and similar elemental segregation. The hardness of alloys declines as the annealing temperature increases while the strength of as-cast alloy improves obviously by the annealing treatment. The electrical conductivities of annealed and as-cast alloys are influenced by the distribution of interdendrite re~ions which is rich in Cu element.     

基于BP神经网络的铸态高熵合金成分-强度预报

对文献报道的铸态高熵合金的成分和压缩断裂强度进行统计,获得了铸态高熵合金成分(元素种类、含量)、强度(压缩断裂强度)的参数,分别以这些数据作为输入和输出,利用BP人工神经网络建立起其间的关系网络模型.研究表明:所建立的网络很好地反映出铸态高熵合金的成分-强度之间的关系并且具有较好的精度,网络模型可用来预测不同成分铸态高熵合金的压缩断裂强度.该网络对铸态高熵合金的体系设计具有有效的指导作用.     

Al含量对CuCrFeMnTiAl高熵合金组织及摩擦磨损行为的影响

根据高熵合金的设计理念制备CuCrFeMnTiAlx(x=0,0.5,1.0,1.5)合金,研究Al含量对该合金系组织结构、硬度及摩擦磨损行为的影响。结果表明:该铸态高熵合金具有简单结构,随Al含量增加,结构由密排六方转变为面心立方;合金的组织为典型的枝晶组织,枝晶间Cu富集的现象明显;合金硬度随着Al含量的增加而升高,其中Al-1.5合金的硬度最高,可以达到7.19GPa;Al-0.5合金在摩擦过程中表面产生氧化区,降低了摩擦系数,因此Al-0.5合金的耐磨性最佳。     

溶胶—凝胶法制备陶瓷涂层的研究现状

陶瓷涂层具有硬度高、耐磨耐蚀性能优异等优点而成为目前研究的热点，溶胶-凝胶技术是制备陶瓷涂层成熟简便的方法之一。综述了国内外采用溶胶-凝胶技术制备陶瓷涂层的体系设计、涂层的物化性能等方面的研究成果，对比分析了现阶段几种陶瓷涂层存在的问题，并对其延伸技术和发展前景进行了总结和展望，可为今后设计制备性能优良和性价比高的陶瓷涂层提供一定的参考。