On the Surface Residual Stress Measurement in Magnesium Alloys Using X-Ray Diffraction

Abstract

X-ray penetration in magnesium alloys is significant due to the low X-ray mass attenuation coefficient. To measure the surface residual stresses in magnesium alloys, a correction needs to be made to account for penetration depth. The residual stresses in as-received and shot peened AZ31B-H24 rolled sheet samples were measured using two-dimensional X-ray diffraction (2D-XRD) method. The electro-polishing layer removal method was used to find the residual stress pattern at the surface and through the depth. The results show that the corrected residual stresses in a few tens of micrometers layer from the surface differ from the raw stresses. To better estimate the residual stress distribution in the surface, the grazing-incidence X-ray diffraction (GIXD) technique was applied. Additionally, micrographs of the lateral cross-section of the peened specimens confirmed the presence of microcracks in this region, causing the residual stresses to vanish. Due to the low X-ray absorption coefficient of Mg alloys, this study shows how a small uncertainty in a single raw measurement leads to high uncertainty in the corrected residual stresses. The results were corroborated with the hole drilling method of residual stress measurements. The corrected X-ray diffraction (XRD) results are in close agreement with the hole drilling and GIXD results.

An Investigation into the Relative Efficacy of High-Velocity Air-Fuel-Sprayed Hydroxyapatite Implants Based on the Crystallinity Index, Residual Stress, Wear, and In-Flight Powder Particle Behavior

“…70 Thus, the HVAF-sprayed HA coating retained compressive residual stress due to high velocity and impact with a low temperature of in-flight particles, which is considered beneficial in nature. Also, the presence of compressive residual stress positively alters mechanical properties 68 and delays crack initiation, leading to a longer life 71 and significantly affecting the tribological performance of the coating by reducing wear debris. 72 Recently, Papanikolaou et al 20 using molecular dynamics simulations, while studying the solidification of aluminum, revealed that the residual stress and crystallinity of the material are inter-related to each other.…”

Study on Physical Mechanisms of Thickness Effect of Incremental Hole-Drilling Method Based on Energy Analysis

“…There are two main categories of residual stress measurement methods: non-destructive and destructive techniques. These include X-ray diffraction [7,8], neutron diffraction [9,10], layer removal methods [11,12], and the incremental hole-drilling method [13][14][15], among others. Each method has its applicability and limitations.…”