Thermal cycling test was carried out for 20 vol% and 40 vol% SiC particle/Al-4 mass%Cu alloy composites to evaluate the bonding strength of the SiC particle/matrix interface in PRMMC fabricated by a low-pressure infiltration process (LPI process). The SiC particles were distributed homogenously in the specimens and a reaction layer of less than 1 mm thickness was observed at the SiC particle/matrix interface before thermal cycling test. This reaction layer was identified as Al 4 C 3 formed by the reaction between the alloy melt and SiC particle during infiltration. The phase, which might form a coherent interface with Al 4 C 3 , crystallized around the SiC particles through the Al 4 C 3 layer. The coefficient of thermal expansion was hardly changed during thermal cycling for both the 20 vol% and 40 vol% SiC particle/Al-Cu composites. No significant change in the microstructure and no detachment at the SiC particle/matrix interface were observed after thermal cycling test. The interfacial structure consisting of SiC, Al 4 C 3 , phase and -Al in order was considered to exhibit a strong bonding of SiC particles to the matrix. The Vickers microhardness measured on the SiC particles in the specimens having a strongly bound interface show hardness values with a small scatter, while those for the specimens having a weakly bound interface exhibit a large scatter in the hardness values. It is suggested that the bonding strength of the reinforcement particle/matrix interface could be evaluated qualitatively from the Vickers microhardness test.
In recent years, human-type robots attract much attention in the field of medical welfare and industrial applications under severe environmental conditions, such as in space. For the realization of such robots, the development of an actuator having superior functions as human fingers is required. It is known that hydrogen storage alloys exhibit a significant volume change of 10-30% on hydrogenation, which is several tens times greater than that caused by thermal expansion. Since the driving force of an actuator driven by hydrogenation is based on phase transformation, the actuator can be expected to show high power. In the present work, a bending module having a sheet form of palladium-base hydrogen storage alloy foils bond with a copper foil was prepared and its bending behaviors were investigated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.