This research investigated how adding Sb (0.75, 1.0, 2.0 and 5.0 wt%) to as-extruded aluminum alloys affected their microstructure, mechanical properties, electric and thermal conductivity. The addition of Sb resulted in the formation of AlSb intermetallic compounds. It was observed that intermetallic compounds in the alloys were distributed homogenously in the Al matrix. As the content of Sb increased, the area fraction of intermetallic compounds increased. It can be clearly seen that the intermetallic compounds were crushed into fine particles and homogenously arrayed during the extrusion process. As the Sb content increased, the average grain size decreased remarkably from 282.6 μm (0.75 wt%) to 109.2 μm (5.0 wt%) due to dynamic recrystallization by the dispersed intermetallic compounds in the aluminum matrix during the hot extrusion. As the Sb content increased from 0.75 to 2.0 wt%, the electrical conductivity decreased from 61.0 to 59.8 % of the International Annealed Copper Standard. Also, as the Sb content increased from 0.75 to 2.0 wt%, the ultimate tensile strength did not significantly change, from 67.3 to 67.8 MPa.

Titanium alloys are extensively used in high-temperature applications due to their excellent high strength andcorrosion resistance properties. However, titanium alloys are problematic because they tend to be extremely difficult-to-cut material. In this paper, the powder synthesis, spark plasma sintering (SPS), bulk material characteristics and machin-ability test of hybrid Ti2AlC ceramic bulk materials were systematically examined. The bulk samples mainly consistedof Ti2AlC materials with density close to theoretical value were synthesized by a SPS method. Random orientation andgood crystallization of the Ti2AlC was observed at 1100℃ for 10 min under SPS sintering conditions. Scanning electronmicroscopy results indicated a homogeneous distribution and nano-laminated structure of Ti2AlC MAX phase. The hard-ness and electrical conductivity of Ti2AlC were higher than that of Ti 6242 alloy at sintering temperature of 1000℃~1100℃. Consequently, the machinability of the hybrid Ti2AlC bulk materials is better than that of the Ti 6242 alloy formicro-EDM process of micro-hole shape workpiece.

In this work, we employed an electroless nickel plating on glass fibers in order to enhance the electric conductivity of fibers. And the effects of metal content and plating time on the conductivity of fibers were investigated. From the results, island-like metal clusters were found on the fiber surfaces in initial plating state, and perfect metallic layers were observed after 10 min of plating time. The thickness of metallic layers on fiber surfaces was proportion to plating time, and the electric conductivity showed similar trends. The nickel cluster sizes on fibers decreased with increasing plating time, indicating that surface energetics of the fibers could become more homogeneous and make well-packed metallic layers, resulting in the high conductivity of Ni/glass fibers.