显微组织对Dy-α-SiAlON刀片切削性能的影响  

Effects of Microstructure Control on Cutting Performance of Dy-α-SiAlON Tool Inserts

作　　者：管政 高北辰 刘利盟[1] Guan Zheng;Gao Beichen;Liu Limeng(School of Materials Science and Engineering,North Minzu University,Yinchuan 750021,China)

机构地区：[1]北方民族大学材料科学与工程学院,宁夏银川750021

出　　处：《山东化工》2023年第15期22-26,共5页Shandong Chemical Industry

摘　　要：采用热压法制备α-SiAlON陶瓷(化学式M_(m/v)Si_(12-(m+n))Al_(m+n)O_(n)N_(16-n),M^(v+)=Dy^(3+),m=1.5,n=1.2),采用添加质量分数0~5%Dy_(2)O_(3)的方法控制少数大晶粒异常长大,获得自韧化双模式组织,研究显微组织对材料维氏硬度、断裂韧性及镍合金切削性能的影响。结果表明,添加质量分数0.5%~1.0%Dy_(2)O_(3)可显著增加Dy-α-SiAlON双模式显微组织中的大晶粒的直径和长径比;把添加量提高到2.5%~5.0%时,大晶粒直径继续增加但长径比减小。在10~20 kg试验载荷条件下测量的维氏硬度在19.0~19.7 GPa范围;断裂韧性具有明显的R-曲线行为,在3.61~4.18 MPa·m^(1/2)范围内随裂纹扩展长度增加而增加。从刀尖、主后刀面、沟槽磨损深度等角度评价Dy-α-SiAlON刀片的切削性能,发现崩刃而非磨损是主要失效机制。Dy-α-SiAlON ceramicsM_(m/v)Si_(12-(m+n))Al_(m+n)O_(n)N_(16-n),M^(v+)=Dy^(3+),m=1.5,n=1.2)were prepared by hot pressing.A small amount of Dy_(2)O_(3)in range of 0~5%was added to control growth of a few large grains to obtain self-toughening bimodal microstructures.Effects of microstructure on Vickers hardness,fracture toughness and cutting performance against nickel alloy were evaluated.The research results showed that average diameter and aspect ratio of the large grains in the bimodal microstructures were significantly increased by addition of 0.5%~1.0%Dy_(2)O_(3).When theDy_(2)O_(3)additions were further increased to 2.5%~5.0%,decrease in aspect ratio was demonstrated.The Dy-α-SiAlON ceramics showed average Vickers hardness of 19.0~19.7 GPa.They exhibited R-curve behavior in which fracture toughness increased in range of 3.61~4.18 MPa·m^(1/2)as crack length increased.The cutting performance of the Dy-α-SiAlON ceramic inserts revealed chipping rather than wear as the main failure mechanism.

关 键 词：Α-SIALON 显微组织 自韧化 力学性能 

分 类 号：TQ174[化学工程—陶瓷工业]