Kiyoshi Mizuuchi1, Kanryu Inoue2, Masami Sugioka1, Masao Itami1, Ken-ichi Hamada3 and Masakazu Kawahara4
1Materials Science & Processing, Osaka Municipal Technical Research Institute, Osaka 536-8553
Magnesium alloy matrix composite reinforced by continuous TiNi shape memory alloy (SMA) wire was fabricated by Pulsed Current Hot Pressing (PCHP) of TiNi SMA wires sandwiched with a pair of AZ31 Mg alloy plates, and its microstructure and mechanical properties were examined. The Mg alloy plates with 20 vol.% of the TiNi wires were readily hot pressed into a composite at the temperature of 773 K for a total processing time of 0.6 ks. During the processing, the thickness of the preform composed of Mg plates and TiNi wires decreased drastically at the temperature between 400 K and 650 K, resulting in the bonding between the wire and the matrix plates. As a reaction occurred insubstantially in the vicinity of the boundary between Mg alloy plates and TiNi wire, no homogeneous interfacial reaction layer was formed. The tensile yield stresses of the composite deformed in tension at 373 and 423 K were higher by about 68 MPa and 87 MPa than that at 293 K, respectively. At the test temperature range, both the yield stress and elongation of the composite increased with increasing temperature. At temperatures higher than 373 K, the specific strength of the composite was higher than that of AZ31 Mg alloy.
magnesium alloy, shape memory alloy, spark plasma sintering, pulsed current hot pressing, metal matrix composite, martensitic transformation
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