Fatigue behavior of Ti6Al4V alloy components manufactured by selective laser melting subjected to hot isostatic pressing and residual stress relief

Abstract

Fatigue behavior (R ε = −1) of HIPed and stress relieved Ti6Al4V alloy specimens produced by selective laser melting (SLM) was analyzed and compared resulting that the hot isostatic pressing (HIP) process caused a microstructural transformation decreasing the hardness and monotonic properties leading to cyclic softening that not allowed fatigue strength to increase. A bilinear behavior in the elastic strain-fatigue life curve was observed due to the decrease of the Young's modulus during the cyclic elastoplastic tests, consequence of subgrains formation. The Smith-Watson-Topper and total strain energy density models adjusted by the bilinear behavior showed a good concordance between predicted and experimental fatigue lives in notched samples.

Fatigue behavior of Ti‐6Al‐4 V alloy manufactured by cold metal fusion

“…The splitting of the strain was done by calculating the elastic strain using Young's modulus E. Determining Young's modulus by reading the plastic strain component from the stabilized hysteresis gave different values for each specimen. This agrees with the observations of Jesus et al 31 and Masendorf. 32 The Coffin-Manson formula requires the use of a uniform Young's modulus, which was determined to be 109,000 MPa via a resonant ultrasonic spectroscopy test.…”

Effects of loading frequency on fatigue behavior of metallic materials—A literature review

“…35 It should be mentioned that in recent decade, AM technology has been increasingly applied to make metal parts for typical applications, especially in biomedical, automobile, and aerospace engineering sectors, and the fatigue performance of AMed metallic materials is one of the major concerns and has been paid great attention to in fatigue and fracture research field. [36][37][38][39][40] Thus, the effect of loading frequency on the fatigue behavior of AMed materials is a new topic although the available results are still limited in the literature. Figure 19 35 is a nice example showing the S-N data of a Ti-6Al-4V made by laser AM with the input energy density of 45.33 J/mm 3 .…”

Microstructure-magnetic shielding development in additively manufactured Ni-Fe-Mo soft magnet alloy in the as fabricated and post-processed conditions

“…M and Tc are intrinsic magnetic properties and their improvement with HIP and HT post-process arises from the improvement in grain size and chemical composition due to Fe and Mo immigration to the main matrix. It is worth mentioning that finishing post-processing with the HT instead of the HIP treatment results in better soft ferromagnetic properties (see Table 2), this is because HIP process, sometimes, doesn't result in a complete stress relief [44], in contrast with HT process in Hydrogen atmosphere that decreases oxides and reliving stresses [45]. Table2: Saturation magnetisation and coercivity of the AF and post-processed HT and HIP samples built with E=4.68J/mm 2 at different orientations.…”