Powder Metallurgy Manufacturing and Characterization of a Cu/ZrO2 Composite Part for Spot welding Electrode Application

Nowadays, there is a wide interest to increase the properties of resistance spot welding electrodes by addition of various ceramic particles to copper base metal. One of the ceramic materials that can be considered as suitable candidate for this purpose is zirconia nanoparticles. The purpose of this study is to use zirconia nanoparticles and then manufacture a copper-zirconia composite part. In this paper, the precipitated synthesized zirconia nano particles of about 90 nm was mixed with copper powder, compacted, and sintered. In order to achieve the optimal conditions for manufacturing of copper-zirconia composite, the effect of three parameters of weight percent of zirconia (1, 2, and 3), compaction pressure (300 to 1000 MPa), and the sintering temperature of 900C were investigated by density, micro hardness, wear resistance, and electrical conductivity, respectively. After optimization of the conditions, the final pellets were prepared with 2 wt% zirconia, compaction pressure of 700 MPa, and sintering temperature of 900C. Finally, The relative density of 92%, micro hardness of 84.8 HV, friction coefficient of 0.607631, and electrical conductivity of about 80 IACS%, was obtained, respectively.

Keywords:

spot welding , resistivity , density , hardness , friction , zirconia , copper