Evaluation of fatigue strength for the reliability of parts produced by direct metal laser sintering (DMLS)

Abstract

This work presents the results of a study to determine the reliability of components manufactured by direct metal laser sintering (DMLS) for fatigue strength. A standard procedure and specimen according to IS 5075-1986 had been used in the experiment. Using Taguchi's experimental design techniques, an orthogonal array of L4 experiments had been developed. Fatigue testing was carried out and analysis of variance (ANOVA) technique was employed to investigate the process parameters in order to identify the main process parameter that affects the performance of the fatigue component. It has been found that scan spacing had more influence on fatigue strength as compared to sintering speed and hatch type. The two-parameter Weibull distribution was adopted to find the reliability of the manufactured components. The Weibull shape parameter and scale parameter was estimated and found approximately by a normal distribution. Micro structural analysis shows that there is a better bonding between the materials when the sintering speed is reduced.