The Use of the Weibull Statistical Method to Assess the Reliability of a Development Engineered Casting Component

Abstract

The work contained herein examines the effect of liquid metal quality, solidification rate, tensile test sample extraction and tensile test preparation, on tensile result reliability as measured using Weibull Statistics. The prototype test casting used for this study was made from sand with two possible sized chills. The level of dissolved hydrogen was examined; as were tensile test sample placement within a cast structure having a gradient of structural fineness imposed by the chill, the effect of increase chill mass, and the effect of sample preparation, on the Weibull Modulus. The test sample population for each iteration was thirty samples, which is reasonable for a Weibull modulus to be determined. A detailed metallographic analysis of the tensile bar fracture surfaces was determined using Light Optical Microscopy (LOM) and Scanning Electron Microscopy in Secondary Electron (SEM/SE) mode.