T10钢表面FeMoCoNiCrTix高熵合金 熔覆层组织及性能

Study on the microstructure and properties of FeMoCoNiCrTix high-entropy alloy cladding layer on T10 steel

采用激光熔覆技术在T10A钢表面制备了FeMoCoNiCrTix(x分别为0.25,0.50,0.75,1.00)高熵合金熔覆层,分析了试样熔覆层及基体界面处的相结构及组织,并利用显微硬度计测试了试样处理前后的截面硬度变化。研究表明,经过激光熔覆在T10A钢表面得到的高熵合金层主要由NiCrFe、NiCrCoMo 2种固溶体为主,其结构分别为BCC结构和FCC结构,熔覆层的组织以柱状枝晶为主,界面处出现等轴晶;随着Ti含量增多,熔覆层由固溶强化变为固溶体与硬质相混合强化,熔覆层的HV硬度达到了792,热影响区的HV硬度达到了620,均高于基体硬度。同时耐磨损性能有了明显提高,磨损方式由粘着磨损逐渐变为磨粒磨损。

FeMoCoNiCrTix(x is 0.25,0.50,0.75,1.00,respectively)high-entropy alloy cladding layer was prepared on the surface of T10A steel by laser cladding technology.The phase structure and microstructure of the interface between the cladding layer and the substrate were analyzed,and the cross-sectional hardness of the sample before and after the treatment were tested respectively by the microhardness tester.The results showed that the high-entropy alloy cladding layer obtained on the surface of T10A steel by laser cladding technology was mainly composed of NiCrFe and NiCrCoMo,two solid solutions whose structures were BCC and FCC,respectively.The microstructure of the cladding layer mainly comprises columnar dendrites,and equiaxed crystals appeared at the interface;As the Ti content increased,the strengthening effect of the cladding layer changed from solid solution strengthening to solid solution and hard phase mixed strengthening.The HV hardness of the cladding layer and the heat affected zone reached 792 and 620,both higher than that of the substrate.At the same time,the wear resistance of the alloy cladding layer witnessed a significant increase and its wear mode gradually changed from adhesive wear to abrasive wear.