金属材料维氏硬度测量不确定度的评定

Uncertainty evaluation of metal material Vickers hardness measurement

维氏硬度测量的不确定度主要来源于试验力、压痕对角线重复性、标准块不均匀性及硬度计本身;建立维氏硬度与试验力、压痕深度的数学模型,指出维氏硬度与试验力成正比,与压痕深度的平方成反比;根据GB/T4340.1—1999,从试验力、压痕、标准块等几个影响因素分析,计算出当包含因子Kp=2,置信区间为95%时,维氏硬度测量的不确定度为2.5%。

The uncertainty of Vickers hardness is from testing force, repeatability of indentation diagonal line, standard block inhomogeneity and hardness tester. The mathematical model of Vickers hardness and testing force, indentation depth is established. Vickers hardness is proportional to testing force, in inverse proportion to square of indentation depth. According to GB/T 4340.1--1999 ,to analyze from following influence factors such as testing force, indentation and standard block, when coverage factor Kp is 2, confidence interval is 95% , the uncertainty of Vickers hardness measurement is 2.5%.