Development of a surface engineering strategy to quantify the sensitivity of surface integrity features in fatigue performance

Abstract

The fatigue performance of a metallic component is strongly correlated with several surface integrity features (surface roughness, residual stresses, microstructure). It is commonly characterised using ISO tests. However, conventional procedures for manufacturing fatigue samples influence all the surface integrity features simultaneously. So, standard fatigue testing procedures do not discriminate between each feature’s sensitivity. This paper aims to show how an advanced combination of various processes (finish turning, belt finishing, roller burnishing) leading to complementary process signatures determines which surface integrity features are the most sensitive and how two features can be coupled. This methodology is applied to a martensitic stainless steel 15-5 PH (precipitation-hardening). It highlights that this steel is very sensitive to the presence of a nanosized white layer and that there is a synergy effect by combining a thick compressive layer and a very low surface roughness.

The role of roughness parameters in grading the machined surface quality in Ti-alloys

“…14 As irregularities (groves and valleys) induce stress concentrations in the surface, higher wear rate, reduced fatigue resistance and a higher tendency for crack propagation may lead to component failure if surface roughness is not accounted for. 15 Besides, for hard tissue replacements, including joints and dental implants, the surface roughness impacts the structural and functional bonding between the implant and the bone, known as osseointegration. 16 For dental implants, turning and threading operations typically provide a smooth surface with an arithmetic average deviation of the roughness profile (R a ) between 0.3 and 0.6 mm.…”

“…14 As irregularities (groves and valleys) induce stress concentrations in the surface, higher wear rate, reduced fatigue resistance and a higher tendency for crack propagation may lead to component failure if surface roughness is not accounted for. 15…”

Surface integrity analysis of aluminum 3003 alloy during ultrasonic-vibration-laser assisted turning

“…1,2 The surface integrity factors include various aspects such as an alteration to surface topography, metallurgical conditions, and mechanical properties on the machined surface and sub-surface region. 3,4 Apart from that, several authors have evaluated machining forces as a part of surface integrity analysis to correlate with various surface integrity factors. 5,6 It was reported that lower machining forces would reduce tool wear which leads to a reduction in surface roughness and improve the metallurgical properties.…”