Improving the Fatigue Strength of L-PBF Manufactured IN718 Samples by HIP Post Processing
Since the interest on additive manufacturing is sharply increasing within the last few years,a lot of research was done to improve the quality of AM-parts.Meanwhile,the achieved density of metal parts,manufactured by laserpowder-bed-fusion(L-PBF)is above 99%.Nevertheless,the mechanical properties,especially the fatigue resistance sometimes are far beneath the material properties of conventionally manufactured parts.Often the reasons are small defects as pores or non-metallic inclusions,resulting from the AM-process.One approach to improve the fatigue strength is post treatment by hot isostatic pressing(HIP).HIP is able to reduce inner porosity but it is not able to dissolve non-metallic inclusions.In this work,the influence of a HIP post treatment on IN718 test samples,manufactured with L-PBF was investigated.The fatigue strength under cyclic loading was determined for two test batches,the first without HIP post treatment and the second with HIP heat treatment.Both batches were heat-treated according to AMS 5662 before mechanical testing.By comparison of both batches concerning microstructure,fatigue strength and fracture analyses,the influence of HIP was investigated.A HIP process subsequent to L-PBF improves significantly the fatigue strength of IN718 samples and significantly reduces the scatter.The reason is not only the decreased porosity,but also the homogenization of the microstructure,which was not achieved with a conventional,pressure less heat treatment for IN718 according to AMS 5662.
Additive Manufacturing Hot Isostatic Pressing HIP Post Treatment IN718,L-PBF SLM
Kaletsch A. Heine L.-M. Kunz J. Bremen S. Schleifenbaum J.H. Broeckmann C.
RWTH Aachen University,Institute for Materials Applications in Mechanical Engineering(IWM),Augustine Institute of Applied Powder Metallurgy and Ceramics at RWTH Aachen e.V.(IAPK),Augustinerbach 4,52062 Fraunhofer Institute for Laser Technology(ILT),Steinbachstraβe 15/17,52074 Aachen,Germany Fraunhofer Institute for Laser Technology(ILT),Steinbachstraβe 15/17,52074 Aachen,Germany;RWTH Aache
国际会议
北京
英文
1665-1672
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）