High Cycle Fatigue Performance of LPBF 304L Stainless Steel at Nominal and Optimized Parameters

Materials

Yitao Chen¹  Tan Pan¹  Frank Liou¹  Sreekar Karnati¹  MohammadMasud Parvez¹  JosephW. Newkirk² 

[1]Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA

[2]Material Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA

关键词: additive manufacturing;    304L stainless steel;    tensile test;    impact toughness test;    fatigue test;    nucleation and propagation;   

DOI  :  10.3390/ma13071591

来源: DOAJ

【 摘 要 】

In additive manufacturing, the variation of the fabrication process parameters influences the mechanical properties of a material such as tensile strength, impact toughness, hardness, fatigue strength, and so forth, but fatigue testing of metals fabricated with all different sets of process parameters is a very expensive and time-consuming process. Therefore, the nominal process parameters by means of minimum energy input were first identified for a dense part and then the optimized process parameters were determined based on the tensile and impact toughness test results obtained for 304L stainless steel deposited in laser powder bed fusion (LPBF) process. Later, the high cycle fatigue performance was investigated for the material built with these two sets of parameters at horizontal, vertical, and inclined orientation. In this paper, displacement controlled fully reversed (R = −1) bending type fatigue tests at different levels of displacement amplitude were performed on Krouse type miniature specimens. The test results were compared and analyzed by applying the control signal monitoring (CSM) method. The analysis shows that specimen built-in horizontal direction for optimized parameters demonstrates the highest fatigue strength while the vertical specimen built with nominal parameters exhibits the lowest strength.

【 授权许可】

Unknown