Effect of temperature on morphology and wear of a Cu-Ti-TiC MMC sintered by abnormal glow discharge

Abstract

Microstructure and tribological properties had been studied in a Cu-Ti-1%TiC MMC with titanium concentration of 10%, 15%, and 20%. The composite was manufactured following the pulvimetallurgical route that included: mechanical and ultrasonic mixing in 2-propanol, compaction at 400 MPa and sintering assisted by abnormal glow discharge in an atmosphere of 10% nitrogen and 90% argon. The discharge was established in the direct current regime and the voltage values were adjusted according to the sintering temperatures of 750°C and 850°C. The sintering process was carried out for 30 min and then cooled in the same atmosphere. As a result, a differentiated in morphology and wear properties were obtained in the sintered parts. At 750°C a microstructure characterized by the stability of Ti grains with intermetallic precipitates such as CuTi 2 and CuTi were observed at the interface with the matrix. On the other hand, the intermetallic phases as Cu 3 Ti, Cu 4 Ti and CuTi 2 had been detected in the sintered at 850°C. These phases were related to diffusive processes that occurred during the sintering, enhanced by the energy provided by the process. It had been observed that with increase of titanium content an improvement of the MMC tribological properties. In titanium contents of 20% at 750°C was estimated a wear coefficient of 2.7 × 10 −8 mm 3 .N −1 .m −1 with a track width of 312 μm. Despite the pores originated during the sintering of MMC at 850°C was found a wear coefficient value of 2.4 × 10 −8 mm 3 .N −1 .m −1 and a track size of 778 μm, related to the plastic deformation exerted on the porous structures during the wear process. Results of the tribological analysis lead that this compound may be applied in fields where the balance between adequate tribological properties and lightness are highly required such as the automotive, aeronautical and biomedical industries.

Evaluation of Mechanical and Tribological Aspect of Self-Lubricating Cu-6Gr Composites Reinforced with SiC–WC Hybrid Particles

“…Copper matrix composite possess excellent properties, including good thermal-electrical conductivity, high mechanical strength, and corrosion [8]. As reinforcement materials, many powder particles, such as SiC (silicon carbide) [9], Al 2 O 3 (aluminium oxide) [10], WC (tungsten carbide) [11], B 4 C (boron carbide) [12], Ti (titanium) [13], TiC (titanium carbide) [14], and TiB 2 (titanium diboride) [3] are used. Akbarpour and Alipour [15], fabricated copper composites reinforced with SiC nanoparticles and studied their wear and friction behaviour under dry sliding conditions.…”

The Effect of Copper Content on the Mechanical and Tribological Properties of Hypo-, Hyper- and Eutectoid Ti-Cu Alloys

“…The equilibrium phase diagram of the Ti-Cu binary alloys indicates that adding more than 3% copper element into titanium alloy has two phases, forming Ti 2 Cu phase and forming needle structure, which can improve the mechanical properties of the material [ 9 , 10 ]. Depending on the specific copper content added to the binary system, Ti-Cu alloys may show distinct microstructures, e.g., eutectoid, hyper- and hypo-eutectoid microstructures, and this allows the possibility for the mechanical behavior of Ti-Cu alloys to be adjusted by controlling the fraction and distribution of Ti 2 Cu precipitation [ 11 , 12 ]. As a kind of structural material for applications at high temperatures, mechanical properties such as strength and ductility are important for Ti-Cu alloys, and these properties represent high dependence on the addition of copper and processing route [ 13 ].…”