Titanium alloys are extensively used in high-temperature applications due to their excellent high strength and corrosion resistance properties. However, titanium alloys are problematic because they tend to be extremely difficult-tocut material. In this paper, the powder synthesis, spark plasma sintering (SPS), bulk material characteristics and machinability test of hybrid Ti2AlC ceramic bulk materials were systematically examined. The bulk samples mainly consisted of Ti2AlC materials with density close to theoretical value were synthesized by a SPS method. Random orientation and good crystallization of the Ti2AlC was observed at 1100°C for 10 min under SPS sintering conditions. Scanning electron microscopy results indicated a homogeneous distribution and nano-laminated structure of Ti2AlC MAX phase. The hardness and electrical conductivity of Ti2AlC were higher than that of Ti 6242 alloy at sintering temperature of 1000°C~1100°C. Consequently, the machinability of the hybrid Ti2AlC bulk materials is better than that of the Ti 6242 alloy for micro-EDM process of micro-hole shape workpiece.
Citations
The connecting rod is one of the most important parts in automotive engines, transforming the reciprocal motion of a piston generated by internal combustion into the rotational motion of a crankshaft. Recent advances in high performance automobile engines demand corresponding technological breakthroughs in the materials for engine parts. In the present research, the powder metallurgy (P/M) process was used to replace conventional quenching and/or tempering processes for mass production and ultimately for more cost-efficient manufacturing of high strength connecting rods. The development of P/M alloy powder was undertaken not only to achieve the improvement in mechanical properties, but also to enhance the machinability of the P/M processed connecting rods. Specifically MoS2 powders were added as lubricants to non-normalizing Fe-Cr-Mn-V-C alloy powder to improve the post-sintering machinability. The effects of MoS2 addition on the microstructure, mechanical properties, and machining characteristics were investigated.