Influence of distortion on part accuracy for indirect metal laser sintering

Abstract

This paper reports on an investigation of dimensional accuracy in additive manufacturing (AM) specifically an indirect metal laser sintering (IMLS) technique. An experimental programme with a series of simple parts has been carried out to establish dimensional accuracy of metal parts made using the three-dimensional (3-D) systems of indirect SLS process. In parallel basic engineering science and experimental has been used to analysed the relative loads experienced by different parts. The experimental data has been used to analyse the level of distortion experienced by parts which undergo infiltration is much less than that of parts which were deliberately not infiltrated; indicating that the early availability of liquid phase is key in avoiding distortion. Analysis has also shown that the propensity for distortion to develop during a sintering or sintering/infiltration step is directly related to the level of stress being experienced by the structure. These two findings show that the application of engineering science to Indirect Metal Laser Sintering could bring parts which are less distorted at the sintering/infiltration stage.