Ti(C,N)基金属陶瓷抗弯强度的Weibull分析  

Weibull analysis on transverse rupture strength of Ti(C,N)-based cermets

作　　者：王晓灵[1,2] 刘咏[1] 

机构地区：[1]中南大学粉末冶金研究院,长沙410083 [2]自贡硬质合金有限责任公司成都分公司,成都610100

出　　处：《粉末冶金材料科学与工程》2017年第4期546-555,共10页Materials Science and Engineering of Powder Metallurgy

摘　　要：作为金属切削工具材料,Ti(C,N)基金属陶瓷强韧性的可靠性是制约其推广应用的主要因素。由于Ti(C,N)基金属陶瓷比WC基硬质合金脆性更大,其强韧性对内外缺陷更敏感,抗弯强度分散性更大,使用时,极易出现突然断裂,失效可预测性低。本文采用Weibull统计强度理论以及双样本t检验的方法对工业化批量生产的Ti(C,N)基金属陶瓷的抗弯强度(TRS)的可靠性及其主要影响因素进行分析。结果显示,物料批次、烧结炉次(烧结气氛)对抗弯强度的分散性有显著影响。同物料批次、同炉次烧结的Ti(C,N)基金属陶瓷样本的抗弯强度具有较大的Weibull模数,最高可达m=41.64,而多物料批次、多炉次烧结样本的抗弯强度的分散性较大,Weibull模数约为10~15,特征强度约为(2350±150)MPa。抗弯强度的Weibull分布还受到样品尺寸的影响,小尺寸样品的特征强度更大,但Weibull模数更小。As a metal-cutting-tool material, the application of Ti（C,N） based cermet is restricted because of its relatively lower reliability of strength and toughness. With much more brittle nature, the Ti（C,N） based cermet is more sensitive to outer and inner defects than WC based cemented carbide, inducing a bigger dispersion of the strength. In applications, the Ti（C,N） based cermet suffers sudden fracture more frequently, and it is difficult to predict the failure of the tools. In this study, the reliability of transverse rupture strength （TRS） of Ti（C,N） based cermet manufactured in industrial scale as well as the influence factors were analyzed using Weibull＇s statistical strength theory and double sample t-testing. The results show that the material batch and the sintering atmosphere have great influence on the dispersivity of the strength. A high Weibull modulus up to 41.64 is obtained in the samples of the same batch sintered in the same furnace. But the values of TRS of the samples from variable batches or different furnaces separate widely. The Weibull modulus is about 10-15, and the characteristic strength is about （2350±150） MPa. Results also indicate significant effect of specimen size on the strength distribution. The characteristic strength of specimens with smaller size is higher, but its Weibull modulus is smaller.

关 键 词：TI(C N) 金属陶瓷 抗弯强度 可靠性 Weibull分析 假设检验 

分 类 号：TF125.31[冶金工程—粉末冶金]