Study On Preparation And Microstructure And Properties Of Foamed Steel

Steel foam is a new type of structure and functional material. It has a low density, high impact energy absorption efficiency,high specific surface area, excellent mechanical strength and good permeability. Therefore, steel foam is an ideal material for making light bearing, filtering element, energy absorbing and shock absorbing equipment. In this paper, we manufactured steel foam and its sandwich board samples with excellent pore structure by the preparation process of mixing-compacting-sintering-dissolution. At the same time, the influence of the experimental conditions on the porosity of the steel foam sample and the influence of the pore structure parameters on the mechanical properties of the steel foam sample were discussed and studied. The main research contents and results are as follows:(1) The porosity of steel foam ranges from 65.9% to 86.3%, pore size ranges from0.5mm to 3.9mm. The pressure and holding time during the extrusion process have little effect on the porosity of samples. The experiment finally makes the sample under the pressure of 400MPa for 5min. The porosity of steel foam decreases with increasing of sintering temperature and holding time, The experiment finally take the sintering process at 120℃ for120min.(2) The platform stress, energy absorption efficiency and elastic modulus of steel foam increase with the decrease porosity of the sample. When the porosity is in the range of 67.7%-83.9%, the plateau stress is 66.4-12.9MPa and the energy absorption per unit volume (W) is 124.8-27.2MJ. The elastic modulus is 13.16-1.91GPa with porosity of 67.1%-86.3%.(3) The maximum bending load of steel foam sample increases with the decrease of porosity or pore size. When porosity is 65.9%-86.2%, the maximum bending load of steel foam sample is in the range of 2383.4-712.6N. When pore size is 1.9-3.9mm,the maximum bending load of steel foam sample is in the range of 1770.3-1105.8N.(4) For the steel foam sandwich panel, the maximum bending load also increases with the decrease of porosity or pore size. When porosity is 65.8%-82.5%, steel foam sandwich panel can bear 2855.7-1247.6N. When size isl.9-3.9mm, the maximum bending load of steel foam sandwich pane is 2070.6-1525.8N.