Texture characterisation of hexagonal metals: Magnesium AZ91 alloy, welded by laser processing

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. ABSTRACTThe objective was to study the mechanical properties of a magnesium alloy welded by a CO 2 laser. Residual stresses were measured by X-ray diffraction. They were calculated by the classic sin 2 Ψ method in the isotropic zones by using the orientation distribution function

Residual stresses of a magnesium alloy (AZ31) welded by the friction stir welding processes

“…The micro hardness decreases slightly in the fusion zone and in the TMAZ (82 ± 2 HV); the slight decrease in the HAZ, where the grain sizes are identical to those in the BM, can be explained by the fact the material has been submitted to a thermal annealing cycle [6,8]. In the welded zone there is a slight reduction in micro hardness despite the fact that the grain size is greatly reduced; the values obtained do not obey the Hall and Petch Law [10]. Within the welded zone the variation of micro hardness can be explained by the fact that the high degree plastic deformation and heating are conducive to the phenomenon of dynamic recrystallization resulting from dynamic recovery.…”

“…Table 1 shows the chemical specification of the AZ31 magnesium alloy supplied. [10] AZ31 magnesium alloys used were rolled to produce 2 mm thin plates from 100 mm ingots which were hot rolled with several passes using a 4 rollers Quarto rolling mill. Strain rates between 5-20% (thickness reduction per pass) and rolling speeds between 0.5-2 m/s were used.…”

“…The texture of the base metal and the texture evolution in FSWelds was studied using XRD techniques. [10,11,12]. We extracted the information's such as the volume fraction of the principal orientation from the ODF (example is given in figure 3 for the zones welded FSW process).…”

“…When a material is not textured, therefore isotropic, the residual stresses were calculated by the sin²Ψ law [10]. …”

Welding of Thin Light Alloys Sheets by CO2 Laser Beam: Magnesium Alloys

“…They reported that for thin AZ31 plates (1, 8 mm), a 1.5 kW beam power was sufficient for achieving full penetration. In our experiences, for achieving full penetration, 3 mm AZ91 plates welds were produced at 4 kW (Kouadri & Barrallier, 2006).…”