Research progress of residual stress determination in magnesium alloys

With the research development of the magnesium alloys, the deformation or stress corrosion induced by residual stress (RS) attracted extensive interests in industry and research efforts extensive. However, there are relatively few studies on the RS of magnesium alloys in the world. The generation cause of RS in magnesium alloys was analyzed at first. Several methods of determinate the RS, including destructive methods (drilling hole, crack compliance, layer exfoliation etc.) and non-destructive methods (X-ray Diffraction, Neutron Diffraction, Short Wavelength X-ray Diffraction) were summarized. The factors that influence the measuring accuracy of XRD method were emphasized. The research trends of RS in magnesium alloys were put forward. Keywords: Residual stress, Magnesium alloys, Stress generation, Stress measuremen

Effect of Uphill Quenching on Microstructure and Residual Stress Reduction of AZ31B Magnesium Alloy Plate

Residual stress may be generated during the deformation process; cold and hot treatments on magnesium alloy, causing deformation; cracking; and other effects. Reducing the residual stress of magnesium alloys is of great significance for its size stability and quality. In this paper, the residual stress in the AZ31B plate was compared with different uphill quenching processes: no uphill quenching (NUQ), liquid nitrogen–boiling water (100 °C) (LNB), liquid nitrogen–hot air (160 °C) (LNHA) and liquid nitrogen–water (25 °C) (LNR). Residual stresses with and without treatment were measured by X-ray diffraction. The effect of uphill quenching on hardness was discussed. The microstructure and diffraction pattern of the samples treated with different uphill quenching processes was investigated by EBSD and XRD. The results showed that the microstructure of magnesium alloy rolling plate was refined by the uphill quenching treatment, which can reduce the residual stress without decreasing the mechanical properties. The largest residual stress reduction rate was obtained by the liquid nitrogen–boiling water process. This treatment process can not only reduce the residual stress of the magnesium alloy rolling plates by 56% but also increase the hardness by 29%

Effect of Uphill Quenching on Microstructure and Residual Stress Reduction of AZ31B Magnesium Alloy Plate

Residual stress may be generated during the deformation process; cold and hot treatments on magnesium alloy, causing deformation; cracking; and other effects. Reducing the residual stress of magnesium alloys is of great significance for its size stability and quality. In this paper, the residual stress in the AZ31B plate was compared with different uphill quenching processes: no uphill quenching (NUQ), liquid nitrogen–boiling water (100 °C) (LNB), liquid nitrogen–hot air (160 °C) (LNHA) and liquid nitrogen–water (25 °C) (LNR). Residual stresses with and without treatment were measured by X-ray diffraction. The effect of uphill quenching on hardness was discussed. The microstructure and diffraction pattern of the samples treated with different uphill quenching processes was investigated by EBSD and XRD. The results showed that the microstructure of magnesium alloy rolling plate was refined by the uphill quenching treatment, which can reduce the residual stress without decreasing the mechanical properties. The largest residual stress reduction rate was obtained by the liquid nitrogen–boiling water process. This treatment process can not only reduce the residual stress of the magnesium alloy rolling plates by 56% but also increase the hardness by 29%

Effect of homogenization annealing on internal residual stress distribution and texture in ME21 magnesium alloy extruded plates

The distribution of residual stresses through thickness of 5 mm-thick ME21 magnesium alloy extruded plates was analyzed non-destructively using short-wavelength X-ray diffraction (SWXRD), and the effect of homogenization annealing before extrusion on the residual stress was discussed. The classic d0 method with an annealed stress-free reference specimen was employed to determine the residual stress of the extruded plates. The residual stress results showed that the gradient of residual stress in the transverse direction was larger than that of the extrusion direction. The homogenization process prior to extrusion weaken the formed sample's texture. The maximum residual stress of the as-extruded plate was reduced, and the residual stress distribution was homogenized. Key words: ME21 magnesium alloy, Homogenization annealing, Residual stress, Short-wavelength X-ray diffractio

Molecular basis of SAP05-mediated ubiquitin-independent proteasomal degradation of transcription factors

Abstract SAP05, a secreted effector by the obligate parasitic bacteria phytoplasma, bridges host SPL and GATA transcription factors (TFs) to the 26 S proteasome subunit RPN10 for ubiquitination-independent degradation. Here, we report the crystal structures of SAP05 in complex with SPL5, GATA18 and RPN10, which provide detailed insights into the protein-protein interactions involving SAP05. SAP05 employs two opposing lobes with an acidic path and a hydrophobic path to contact TFs and RPN10, respectively. Our crystal structures, in conjunction with mutagenesis and degradation assays, reveal that SAP05 targets plant GATAs but not animal GATAs dependent on their direct salt-bridged electrostatic interactions. Additionally, SAP05 hijacks plant RPN10 but not animal RPN10 due to structural steric hindrance and the key hydrophobic interactions. This study provides valuable molecular-level information into the modulation of host proteins to prevent insect-borne diseases

htcondor/htcondor-ce: HTCondor-CE 23.0.1

<ul> <li>Add condor_ce_test_token command</li> </ul&gt