Evaluation of Nitriding and Surface Machining Effects on Tensile and Fatigue Properties of Additively Manufactured Ti6Al4V
Ti-6wt%Al-4wt%V(Ti64)Additively Manufactured(AM)components are now established in prototyping and small volume niche product manufacture.In recent years there has been a move into increased volume end use products in more demanding applications.These include products where fatigue performance is critical,such as; medical implants,aerospace and automotive.Fatigue strength of AM Ti64 material is typically lower than that of wrought Ti64,presenting a need to fully characterize this behaviour.Compromised fatigue strength may exclude some applications from using AM or lead to overly conservative component design,therefore not taking full advantage of the manufacturing process.This study characterized the fatigue strength of AM Ti64 samples and compared the influence of two practical surface modifications on fatigue strength; surface finish improvement by machining and surface hardness improvement by nitriding,following a commercial process.Rotating bend fatigue test specimens and tensile test specimens were manufactured using an EOS M270 Selective Laser Melting(SLM)system.Samples were prepared with as-built surfaces and some with post-machined surfaces.All specimens had a nominal 5mm diameter as-tested.Both surface types were tested in stress relieved and nitrided conditions.An additional test condition of the nitriding thermal treatment but in argon atmosphere(annealing)was used to isolate thermal and chemical modification effects on fatigue performance.Rotating bend fatigue testing,tensile testing,micro-hardness measurements and fractographic imaging were used to assess the materials performance.The surface effects of nitriding and machining on fatigue strength of SLM AM Ti64 samples are presented.The potential of nitriding and surface machining as practical methods for influencing the fatigue strength in AM parts is discussed.
Additive Manufacture selective laser melting Ti64 fatigue nitride surface finish thermal treatment
Mukhtar Aamir Fry Mike Jackson Ben
TiDA Ltd.,70 Windermere drive,Poike 3112,Tauranga,New Zealand
国际会议
北京
英文
1575-1583
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）