Ti含量对CrCoNiTi_(x)中熵合金组织与性能的影响

铸态CrCoNi中熵合金相比传统合金具有优异的性能,但其室温强度不高,限制了其应用。采用合金化法,通过添加不同含量的Ti元素,制备铸态CrCoNiTi_(x)(x=0、0.2、0.4、0.5)中熵合金,研究不同Ti含量对CrCoNiTi_(x)中熵合金的物相结构、微观组织、力学性能的影响。结果表明:x=0.2时,合金组织中析出Ni_(3)Ti金属化合物,合金的强度提高到643 MPa,延伸率降低至24%,x=0.4时,组织中析出Ni_(3)Ti与Cr_(3)Ni_(2)金属化合物,强度和延伸率急剧降低,x=0.5时,合金几乎无塑性,但硬度达到最高,为769.51 HV。添加Ti元素后,由于金属化合物的产生,合金脆性增加,硬度增加,若要使合金的强韧性较好,Ti元素含量应小于0.2,添加Ti元素后,合金的耐腐蚀性下降。

Effect of Ti content on microstructure and properties of CrCoNiTix Medium Entropy Alloy

The as-cast CrCoNiTix medium entropy alloy (x = 0, 0.2, 0.4, 0.5) was prepared by alloying method by adding different contents of Ti element. The effect of different Ti content on the phase structure, microstructure and mechanical properties of entropy alloy in CrCoNiTix was studied.The experimental results show that: When x=0.2, Ni3Ti metal compounds are precipitated in the alloy microstructure, and the strength of the alloy increases to 643MPa, and the elongation decreases to 24%. When x=0.4, Ni3Ti and Cr3Ni2 metal compounds are precipitated in the alloy microstructure, and the strength and elongation decrease sharply. When x=0.5, the alloy has almost no plasticity, but the hardness reaches the highest. 769.51 HV. After the addition of Ti element, the brittleness and hardness of the alloy increase due to the generation of metal compounds. In order to improve the strength and toughness of the alloy, the Content of Ti element should be less than 0.2.