Additive manufacturing (AM) is a manufacturing process which has gotten an increased interest during the last decades, in several industries. One group of AM technologies that is of major interest for the aerospace industry is laser metal wire deposition (LMD-w), which is the focus of this study.

LMD-w is a relatively new manufacturing technology, several questions regarding what influences the crack probability and microstructure of the final deposit are left unanswered. Two of the parameters that may have an influence on this, are deposit material and waiting time between layers. Therefore, to increase the knowledge in the areas of crack initiation and microstructure, these two parameters are investigated in this thesis. Choice of deposition materials to be investigated are Waspaloy, Haynes 282 and Inconel 718 and the waiting time between layers are normalized to be 1, 5 and 10. The remaining process parameters are left constant.

This thesis is based on extensive literature research that are followed by deposition and examination of the 21 samples produced. This resulted in that choice of deposition material gave a small influence of crack initiation. However, chosen waiting time had influence of both crack initiation and microstructure. The cracks were located on top of the walls and were localized around grain boundaries. The morphology of the samples was of columnar dendritic structure or a mix of columnar and equiaxed zones, depending on the waiting time chosen.