Selective Laser Sintering Induced Residual Stresses: Precision Measurement and Prediction

Susan Impey,Konstantinos Salonitis,Prateek Saxena

doi:10.3390/jmmp5030101

Abstract

Additive Manufacturing presents unique advantages over traditional manufacturing processes and has the potential to accelerate technical advancement across multiple sectors, permitting far greater freedom in design than conventional manufacturing. However, one barrier which blocks wide adoption is residual stresses, which could seriously affect the materials’ behaviour during and after production. Selective laser sintering (SLS), a process with high energy input to the workpiece material, induces high temperature gradients, further affecting the final residual stress distribution. Within the present paper, three different methods for the assessment of the residual stresses’ distribution are presented and compared: a non-destructive method based on neutron diffraction, a destructive method known as the contour method, and a theoretical approach based on Finite Element Analysis. The aim is to examine the suitability and reliability of the application of these methods in predicting residual stresses distribution in additive manufacturing-built parts.

Highlights

The aim of this paper is to examine the suitability and reliability of the application of neutron diffraction in measuring residual stresses distribution in Additive Manufacturing (AM) built parts
(AM) presents presents unique unique advantages advantages over over traditional traditional manumanufacturing processes and shows good repeatability, but residual stresses are generated facturing processes and shows good repeatability, but residual stresses are generatedin in manufacturing manufacturingprocesses, processes,so sopost-treatments post-treatmentsare arerequired requiredtotorelease releaseresidual residualstresses
The contour method is another good technique which can map residual stress on the whole surface. Apart from these good technique which can map residual stress on the whole surface. Apart from these experimental methods, Finite Element Analysis (FEA) modelling shows its advantages in analysing components experimental methods, FEA modelling shows its advantages in analysing components both during and after the manufacturing process

Summary

Introduction

One barrier which blocks wide adoption of the technique is unfavourable residual stresses, which could seriously affect the materials’ behaviour during and after production [4,5]. This unpredictability costs industry millions of pounds in time and materials due to the slow and iterative approach needed to design and build parts. It is necessary to predict and determine the distribution of residual stresses in AM built parts, especially when required in high-reliability areas, to have the residual stresses under control. Research has been reported in simulating the processes for predicting the residual stresses profiles [1,2,6], the precise and accurate measurement of such residual stresses profiles has still not been thoroughly investigated

Objectives

Methods

Discussion

Conclusion