W. L. E. Wong

Development of Metallic Materials Using Hybrid Microwave Assisted Rapid Sintering

Powder metallurgy is a highly established method for fabricating metals and metal matrix composites. An innovative hybrid sintering technique involving the use of microwaves and radiant heating is currently proposed. The use of microwaves to heat metallic materials is not common because it is a well known fact that bulk metals reflect microwaves and causes arching when placed inside a microwave oven. Microwave heating of materials is fundamentally different from conventional resistance heating and offer many benefits over conventional heating. In this study, aluminum, magnesium and a lead-free solder were selected as candidate materials and sintered using conventional sintering as well as a novel hybrid microwave assisted sintering. The sintered materials were hot extruded and characterized primarily in terms of physical and mechanical properties. An overall superior combination of hardness and tensile properties were realized in the case of microwave sintered samples when compared to the conventionally sintered samples.© 2005 ASME

Development of Mg/Cu Nanocomposites Using Microwave Assisted Powder Metallurgy Technique

In the present study, magnesium composites containing different amount of nano-size copper particulates were successfully synthesized using powder metallurgy technique coupled with a novel microwave assisted rapid sintering. Mg/Cu nanocomposites were sintered using a hybrid heating method consisting of microwaves and radiant heat from external susceptors. The sintered specimens were hot extruded and characterized in terms of microstructural, physical and mechanical properties. Microstructural characterization revealed minimal porosity and the presence of a continuous network of nano-size Cu particulates decorating the particle boundaries of the metal matrix. Mechanical characterization revealed that the addition of nano-size Cu particulates lead to an increase in hardness, 0.2% yield strength (YS) and ultimate tensile strength (UTS) of the matrix. An attempt is made in the present study to correlate the effect of increasing presence of nano-size Cu reinforcement on the microstructural, physical and mechanical properties of monolithic magnesium.© 2005 ASME

Development of High Performance Mg/SiC Composites Containing Nano-Size SiC Using Microwave Assisted Rapid Sintering

Magnesium composites containing nano-size silicon carbide (SiC) particulates were synthesized using powder metallurgy technique coupled with a novel microwave assisted rapid sintering. The sintered specimens were hot extruded and characterized in terms of microstructural, physical and mechanical properties. Microstructural characterization revealed minimal porosity and the presence of a continuous network of nano-size SiC particulates decorating the particle boundaries of the metal matrix. Thermal mechanical analysis revealed a marginal reduction in the average coefficient of thermal expansion (CTE) values of the matrix with the addition of nano-size SiC reinforcement. Mechanical characterization revealed that the addition of nano-size SiC particulates lead to an increase in microhardness, 0.2% yield strength (YS), ultimate tensile strength (UTS) and ductility of the matrix. Particular emphasis was placed to correlate the effects of nano-size SiC reinforcement on the microstructural, physical and mechanical properties of monolithic magnesium.Copyright