Microstructure and tensile properties of thixoformed A356 alloy

Effect of Thixoforming on the Microstructure and Tensile Properties of A356 Alloy and A356-5TiB2 In-situ Composite

“…5d). These results are in agreement with Mandal et al [12]. Further, the features of the semi-solid state samples with predominantly globular a-Al grains in both the alloy and composites are shown in Fig.…”

“…The peak three corresponds to the liquidus (615, 618°C), peak 2 corresponds to eutectic (567, 571°C) and peak 1 corresponds to the solidus (555, 560°C) temperatures of the alloy and composites respectively. It is generally claimed that 30-50 % liquid is needed in the feedstock for thixoforming process [12,13]. Hence, the A356 alloy specimens were soaked at a temperature of 580°C and the A356-5TiB 2 composite specimens were soaked at 585°C which corresponds to solid fraction f s = 0.5 respectively, as shown in Fig.…”

“…Amongst the thixoforming processes available, forging has considerable potential for severe plastic deformation and improvement in mechanical properties [11]. The investigations made by the research group Tahamtan et al [12,13] showed significant improvement in tensile properties of thixoforged A356 alloy compared to rheocast and gravity-cast samples of the same alloy. Recently, in situ reinforced Aluminum based metal matrix composites are emerging as one of the most promising alternatives for eliminating the inherent defects associated with ex situ reinforced MMCs.…”

The room temperature mechanical properties of a thermo-mechanically processed Thixocast A356 aluminum alloy

“…As is seen, thermo-mechanically pro- cessed specimens exhibit higher UTS in all temperatures and strain rates than that of the as-thixocast alloy (ultimate shear strength of as-thixocast alloy is obtained of 148 MPa; using Eq. (1) and correlation coefficients of 0.67, the ultimate tensile strength will be 221 MPa, which is in good agreement with maximum stresses in tension values reported for as-thixocast A356 in the literatures) [1,30,31]. Also, it has been reported that applied pressure increases the primary alpha phase micro-hardness [26].…”

An Overview of Semisolid Processing of Aluminium Alloys

“…ese alloys provide high �uidity and good castability and usually used in fabrication automobile components. Forming an alloy in the semisolid state condition requires a roughly spherical �ne grain microstructure uniformly dispersed in a liquid matrix when it enters the forming die [37,38]. When this microstructure is reheated, the grain boundaries start to melt and a new secondary phase also takes place.…”