Effects of strain rate on mechanical properties, microstructure and texture of Al-Mg-Si-Cu alloy under tensile loading

The effects of strain rate on the mechanical properties,microstructure and texture of Al-Mg-Si-Cu alloy were investigated through tensile test,microstructure and texture characterization.The results show that strain rate has some influences on the mechanical properties and microstructure,but a slight influence on the texture.Overall,yield strength,ultimate tensile strength and elongation increase first,then remain unchanged,and finally increase with increasing strain rate.Independent of strain rate,microstructure in the vicinities of the fracture regions of all the specimens is composed of the slightly elongated grains.However,some differences in misorientation angle distributions can be observed.As strain rate increases,the low angle grain boundaries(LAGBs)increase first,and then decrease.Textures in the vicinities of the fracture regions are almost identical with increasing strain rate.

Relationship among solution heating rate,mechanical properties,microstructure and texture of Al−Mg−Si−Cu alloy

The relationship among heating rate, mechanical properties, microstructure and texture of Al-Mg-Si-Cu alloy during solution treatment was investigated through tensile test, scanning electron microscope, X-ray diffractometer and EBSD technology. The experimental results reveal that there is a non-monotonic relationship among solution heating rate, mechanical properties, microstructure and texture. As the solution heating rate increases, the strength variations are dependent on the tensile direction;work hardening exponent n decreases first, and then increases;plastic strain ratio r increases first, and then decreases, and finally increases. The final microstructure and texture are also affected by heating rate. As heating rate increases, the microstructure transforms from elongated grain structure to equiaxed grain structure, and the average grain size decreases first, and then increases, and decreases finally. Although the texture components including CubeND{001}<310> and P{011}<122> orientations almost have no change with the increase of heating rate, the texture intensity and volume fraction decrease first, and then increase, and finally decrease. Both microstructure and texture evolutions are weakly affected by heating rate. Improving heating rate is not always favorable for the development of fine equiaxed grain structure, weak texture and high average r value, which may be related to the recrystallization behavior.

Effect of tempering on bonding characteristics of cross wedge rolling 42CrMo/Q235 laminated shafts

To further improve the comprehensive properties of 42CrMo/Q235 laminated shafts produced by cross wedge rolling.theheat treatment of the shafts was studied.Tensile and bending tests were carried out to compare the changes in mechanicalproperties before and after heat treatment.The results showed that the interfacial bonding strength increased most aftertempering at 350℃for 45 min.The microstructure of the interface was observed using a digital microscope.The resultsshowed that the dispersed oxides on the interface were basically eliminated by using the scheme of tempering at 350 cand holding for 45 min.The reasons for the change in mechanical properties were explained from the point of theinterfacial microstructure.Scanning electron microscopy was used to analyze the micro-morphology of the tensile fracture.lt was observed that after tempering at 350℃and holding for 45 min,the dimple holes became larger and deeper,and thestructure of fracture became more uniform and stable.From the point of the tensile fracture morphology.the reasons for thechange in mcchanical propcrties wcrc explained as well.

Influence of process parameters on interracial tensile strength of crosswedge rolling of 42CrMo/Q235 laminated shafts

Through rolling experiments and interfacial tensile strength tests of cross-wedge rolled laminated shafts of 42CrMo/Q235 composites, the influence of process parameters, including forming angle, spreading angle, area reduction, rolling temperature and core material diameter on the interfacial shear strength was analyzed. The results show that the sequence of process parameters in order of greatest influence on interfacial tensile strength was rolling temperature, area reduction, core material diameter, forming angle and spreading angle. At the interface of the combined materials, tensile strength decreased as forming angle and spreading angle increased, whereas the tensile strength first increased and then decreased as area reduction, rolling temperature and core material diameter increased.