截点法测量金属平均晶粒度的不确定度评定及分析  

Evaluation and Analysis on Uncertainty of Measuring Metal Average Grain Size by Intersection Point Method

作　　者：刘松[1] LIU Song(AVIC Nanjing Engineering Institute of Aircraft Systems,Nanjing 211106,China)

机构地区：[1]航空工业金城南京机电液压工程研究中心,南京211106

出　　处：《失效分析与预防》2020年第1期6-11,共6页Failure Analysis and Prevention

摘　　要：分别利用金相显微镜目镜和金相分析软件手动计数测量的方式,采用截点法对均匀等轴晶粒的平均晶粒度结果测量不确定度进行评定研究,分析影响其测量不确定度的主要来源。结果表明:目镜测量平均晶粒度的平均截距值为35.7μm,U=2.1μm,k=2;金相分析软件测量平均晶粒度的平均截距值为35.5μm,U=0.4μm,k=2。金相显微镜放大倍率偏差致使试验线长度引入的不确定度分量是应用目镜测量平均晶粒度结果不确定度的主要来源;而使用金相分析软件手动测量平均晶粒度结果测量不确定度主要来源,却是由测量的晶界与试验线的交点数的不确定度分量引入的。在其他条件均相同的情况下,使用金相分析软件手动测量平均晶粒度比应用目镜直接测量平均晶粒度,更能缩小结果在相同包含概率下不确定性的范围,提高准确度。而对于均匀等轴晶粒的平均晶粒度测量,直线截点法和圆截点法对最终的不确定度的评定结果影响不大。The measurement uncertainty of the average grain size was evaluated for equiaxed grains by means of optical microscope eyepiece and manual counting method with analysis software.The main sources affecting measurement uncertainty were analyzed.The results show that the average intercept measured by eyepiece is 35.7μm,U=2.1μm,k=2.The average intercept measured by analysis software is 35.5μm,U=0.4μm,k=2.The main source of the average grain size measurement uncertainty with eyepiece is the test line length due to the microscope magnification deviation.The main source of the average grain size measurement uncertainty with analysis software is the deviation of intersection points between the grain boundary and the test line.Under the same conditions,the manual measurement average grain size with analysis software can reduce the uncertainty range of the results in the same probability.It can improve the accuracy compared with direct measurement using eyepiece.There is little difference between straight line intersection point method and circular intersection point method for the equiaxed grains in the average grain size uncertainty evaluation.

关 键 词：不确定度 平均晶粒度 截点法 

分 类 号：TB302[一般工业技术—材料科学与工程]