Study On Preparation Technology And Properties Of Copper And Copper Alloy Foam

Copper-based foam is a new developmental structure-function material in the metallic foam research field in recent years. Copper-based foam has many advantages, such as light weight, good thermal conductivity and large surface area, high impact energy absorption efficiency, good permeability performance, etc. Copper-based foam has been widely used in thermal materials, filtration materials, energy-absorbing materials. The goal of the research work is to manufacture copper-based foam by SDP with CaCl₂ as pace holder. This paper mainly introduces the preparation process of copper foam and bronze foam, the influence of experimental conditions on the porosity, the effect of pore parameters on the mechanical and filtration properties of copper-based foam, research and results are as follows:（1） Copper foam and bronze foam were succeeded prepared with CaCl₂ as space holder. The porosity of copper foam ranges from 75.88% to 91.05%, and cell size from 1.0mm to 2.5mm, and its open pore proportion is above 0.88. The porosity of bronze foam ranges from 70.47% to 88.32%, cell size ranges from 1.0mm to 2.5mm and its open pore proportion is above 0.9. The porosity of fiuation bronze foam ranges from 22.78% to 49.73%, and diameter from 26.7mm to 30.6mm, and thickness from 1.6mm to 2.9mm.（2） The yield plateau stresses of the copper foam and bronze foam both increase with the decrease of porosity and cell size, the yield plateau stress of spherical pore are higher than irregular pore, The yield plateau stresses of the copper foam and bronze foam both match the Gibson-Ashby empirical formula. When cell size is 2.0mm, the yield plateau stress of copper foam with the porosity between 75.88% and 90.19% is in the range of 12.1-1.2MPa, the yield plateau stress of bronze foam with the porosity between 70.47% and 85.06% is in the range of 26.5-4.5MPa.（3） The elastic modulus of the copper foam and bronze foam both increase with the decrease of porosity and cell size. The elastic modulus of the copper foam and bronze foam both match the Gibson-Ashby empirical formula. When cell size is 2.0mm, the elastic modulus of copper foam with the porosity between 76.02% and 89.45% is in the range of 0.66～0.15GPa, the elastic modulus of bronze foam with the porosity between 70.62% and 88.32% is in the range of 21.62-0.19GPa.（4）The energy absorption per unit volume （W） of copper foam with the porosity between 75.88% and 90.19% is in the range of 15.8-3.6 MJ/m3 when cell size is 2.0mm. The energy absorption per unit volume （W） of bronze foam with the porosity between 70.47% and 85.06% is in the range of 78.6-12.1 MJ/m3 when cell size is 2.0mm. The maximum ideality energy absorption efficiency of bronze foam is about 0.78 While copper foam is about 0.74. All the results indicate that the bronze foam and copper foam can be used as good absorbing materials.（5）The porosity, maximum cell size, permeability, shrinkage rate of filtration bronze foam both decrease with the increase of pressure stress. The maximum cell size firstly decreases and secondly increases with increasing temperature. When the pressure strength is 150Mpa, sintering temperature is 800"C, holding time is 1.0h, the porosity of filtration bronze foam is 32.18%, maximum cell size is 4.6μm, permeability is 9.27 m3/（h·kPa·m2） and compressive strength is 27.9MPa.