1. Impact energy absorption characteristics: The high-t […]
1. Impact energy absorption characteristics: The high-temperature resistant aluminum foam material has a unique network, non-directional porous structure, and has no rebound effect. Through the stress-strain test of this material, it is found that its strain strongly lags behind the stress, and a long smooth section is included in the compressive stress-strain curve. Therefore, high-temperature resistant aluminum foam is a kind of high impact energy absorption characteristic. material.
2. Light weight and low density: The tensile strength of high temperature resistant aluminum foam is relatively low, and the specific strength is also low, but the compressive strength and bending strength are high. The tensile strength is only about 1/100 of that of aluminum, and the specific strength is about 1/10 of that of aluminum. Aluminum foam has poor rigidity. For example, high-temperature resistant aluminum foam does not have the ductility of aluminum and hardly undergoes plastic deformation under pressure. The elastic modulus measured by bending test is about 1/50～1/100 of aluminum alloy.
3. Conductivity: Only a small part of the cross-sectional area of porous aluminum material is aluminum, and most of them are composed of pores filled with gas. The conductivity is determined by the performance of the base aluminum. In addition, there is an oxidized surface on the wall of the pores, which cannot conduct electricity with the gas. Therefore, the ratio of aluminum to pores on the cross section determines the conductivity of the foam material. Therefore, the greater the porosity, the worse the conductivity. When the density of high-temperature resistant aluminum foam increases, its conductivity will also increase.
4. Acoustic and electromagnetic properties: For through-hole aluminum foam, when sound waves touch the aluminum surface, they diffusely reflect into the pores of the high-temperature resistant aluminum foam, causing the aluminum to vibrate and convert sound energy into heat energy, which plays the role of silencer. The high-temperature-resistant aluminum foam was tested with electromagnetic waves, and it was found that the high-temperature resistant aluminum foam also has the effect of absorbing electromagnetic waves, so the high-temperature resistant aluminum foam also has a shielding effect on electromagnetic waves.
5. Thermophysical properties: High temperature resistant aluminum foam generally has high heat resistance, and does not dissolve even if the temperature reaches the melting point of the base alloy. For example, the operating temperature range of ALMAG alloy is 560～640℃, but the foam alloy of ALMAG alloy is It does not dissolve when heated to 1400°C in the atmosphere. Permeability: It is another characteristic of through-hole aluminum foam. By adjusting the pore structure of the aluminum foam, such as porosity, pore size, and through-hole degree, foam aluminum materials with different permeability requirements can be obtained.