Preparation And Properties Of Cu-Gd₂O₃Composite Material

Because of the high strength and thermal conductivity properties of copper-basedcomposite material, it was widely used in aerospace, electronic and other fields. Rare earthoxides which had high melting point and strength were doped in metal material. It cannotonly form stable oxide particle defects under high temperature; but also increase tensilestrength, improve friction and wear properties and ablation resistance.In this paper, raw material powder was uniformly mixed with a planetary ball mill.Cu-Gd2O3composite materials were fabricated by spark plasma sintering meter, andproperties under different preparation process were tested. Changed the addition ofenhanced phase Gd2O3, the physical and mechanical properties of sintered material weretested to get the best added amount of Gd2O3. The interfacial reaction and interfacial phasebetween matrix and reinforced phase, tribological properties of Cu-Gd2O3compositematerials were observed and analyzed by X-ray diffraction, transmission electronmicroscopy, scanning electron microscopy, optical microscope and high-speed friction andwear testing platform.The experimental results demonstreted that the optimized process of Cu-Gd2O3composite materials was600min, ball feed ratio5:1, rotational speed180r/min, sinteringtemperature900oC, holding time10min, sintering pressure30MPa. The best properties ofthe composite material were tensile strength311MPa, conductivity80%IACS，at this timeGd2O3added amount is6wt.%,XRD and TEM analyzed the interface and component existing form betweenenhanced phase and substrate. Gd2O3and Cu formed a reaction layer at the interfacewhich is a transition Gd2CuO4, this new phase surrounded Gd2O3forming a transitionlayer structure. The thickness of the reaction layer and transition zone became broadenwith the increase of the temperature. It was an effectively way to improve the mechanicalproperties of materials by the control of the thickness of reaction layer.At a lower sliding speed, wear mechanism of the composite was slightly abrasionworn. With the increases of sliding velocity, abrasive wear gradually worsened and finally turned into delamination wear. When slinding speed was50m/s,wear rate was0.64mg/m.In the initial stage of friction testing granular debris compacted with substrate materialformed the surface mixed layer. As the slide distance extended, mechanical mixing layerscaly droped off, scaly morphology and granular off point appeared. When slide distancewas1250m, wear rate was0.70mg/m...