Effects of reheating duration on the microstructure and tensile properties of in situ core–shell-structured particle-reinforced A356 composites fabricated via powder thixoforming

Core-Shell-Structured Particle Reinforced A356 Matrix Composite Prepared by Powder-Thixoforming: Effect of Reheating Temperature

“…According to Formulas (7) and (9), it can be found that increases with the increase of shell thickness (i.e., the increase of A 1 ), and thus, the strengthening role to the matrix is improved. This is consistent with the experimental results from both the present work and Reference [ 15 ], the thicker the compact shells are, the higher the YS will be.…”

“…As for the multi-phase or multi-structure particle reinforced metal matrix composites, i.e., the core-shell-structured particle reinforced composites, there is only one paper from the authors, which predicted the YS of the Ti@(Al-Si-Ti) p /A356 matrix composites thixoformed under different reheating durations at 600 °C, based on the above model [ 15 ]. As discussed in Section 3.2 , the strengthening role of this kind of reinforcements varies with the reheating temperature because their microstructure and phase constituent change with the temperature.…”

“…The employed vacuum was less than 10 −2 Torr. The previous investigation indicated that heating for 50 min at 600 °C could obtain ideal core-shell-structured Ti@(Al-Si-Ti) p and the resulting composite had high performance [ 15 ], so the reheating time in this work was set to 50 min. Finally, the heated compacts were quickly handled into a mould with a cavity of Φ 50 mm × 30 mm and thixoformed at a pressure of 150 MPa respectively.…”

“…The results indicated that Si element participated in the reaction between Ti powders and Al melt, and an ideal core-shell-structured Ti@(Al-Si-Ti) p with a thick and compact Al-Si-Ti compound shell was obtained in A356 alloys after being properly heated at semisolid temperatures. More importantly, the authors studied the effects of one main processing parameter—reheating time at semisolid temperature of 600 °C—on the microstructure and tensile properties of the resulting composites [ 15 ]. The results showed that the Ti@(Al-Si-Ti) p /A356 matrix composite formed at reheating for 50 min had an ultimate tensile strength (UTS) of 371 MPa, yield strength (YS) of 268 MPa, and elongation of 8.3%.…”

“…For the powder thixoforming technology, reheating temperature, mould temperature, punch velocity, and pressure are equally important processing parameters with the reheating time. So far, only one paper studied the effects of reheating time on the microstructure and tensile properties of the Ti@(Al-Si-Ti) p /A356 matrix composite as mentioned above [ 15 ]. Therefore, the effects of reheating temperature were investigated in this work.…”