On the Effect of the Stress Ratio on Fatigue Properties of Ti-6Al-4V Produced by Laser Powder Bed Fusion

Fatigue life estimation of Ti-6Al-4V parts produced by additive manufacturing (AM) technologies has received increasing interest during the last decade. Recent studies focused mostly on the fatigue performance of Ti-6Al-4V considering a fixed stress ratio ( R ), usually 0.1 or −1. However, in order to properly design structural components subjected to variable loads, the effect of different stress ratios on the fatigue performance has to be carefully investigated. This research studies the stress ratio influence on the fatigue properties of Ti-6Al-4V specimens produced by laser powder bed fusion (L-PBF). Miniaturized Ti-6Al-4V samples were tested with the step procedure for different R values. A constant life Haigh's diagram ( 2 · 1 0 6 cycles) was generated for L-PBF Ti-6Al-4V in as-built, electro-polished, and machined surface condition. The results present for the first time the relations between alternating and mean stresses for L-PBF Ti-6Al-4V with a fine α + β microstructure when different surface posttreatments are used to enhance the coupons’ final surface quality.</jats:p

On the Effect of the Stress Ratio on Fatigue Properties of Ti-6Al4V Produced by Laser Powder Bed Fusion

Fatigue life estimation of Ti-6Al-4V parts produced by additive manufacturing (AM) technologies has received increasing interest during the last decade. Recent studies focused mostly on the fatigue performance of Ti-6Al-4V considering a fixed stress ratio (), usually 0.1 or −1. However, in order to properly design structural components subjected to variable loads, the effect of different stress ratios on the fatigue performance has to be carefully investigated. This research studies the stress ratio influence on the fatigue properties of Ti-6Al-4V specimens produced by laser powder bed fusion (L-PBF). Miniaturized Ti-6Al-4V samples were tested with the step procedure for different values. A constant life Haigh's diagram ( cycles) was generated for L-PBF Ti-6Al-4V in as-built, electro-polished, and machined surface condition. The results present for the first time the relations between alternating and mean stresses for L-PBF Ti-6Al-4V with a fine microstructure when different surface post-treatments are used to enhance the coupons’ final surface quality.status: publishe

On the role of building orientation and surface post-processes on the fatigue life of Ti-6Al-4V coupons manufactured by laser powder bed fusion

status: Published onlin

Effect of post-treatments on the fatigue behaviour of 316L stainless steel manufactured by laser powder bed fusion

This paper investigates the influence of post treatments on the fatigue properties of 316L stainless steel produced by laser powder bed fusion. Miniaturised fatigue samples are built in vertical orientation with optimised process conditions to result in very low porosities and minimal scatter in results. Fatigue performance is evaluated for two different material conditions: as-built and stress-relieved, at a nominal load ratio of −1. Furthermore, the samples are tested with and without surface machining. A thorough microstructural and fractographic analysis is performed to evaluate the impact of the main fatigue influencing factors. The results show that the fatigue behaviour of machined samples with and without stress relief heat treatment exceeds that of conventionally manufactured 316L. © 2019 Elsevier Lt

Fatigue life prediction of a L-PBF component in Ti-6Al-4V using sample data, FE-based simulations and machine learning

status: Published onlin

Predicting fatigue life of metal LPBF components by combining a large fatigue database for different sample conditions with novel simulation strategies

status: Published onlin