| The metal foams is a kind of structural and functional material. Recently, the researches about metal foams are very active. It is not only a part of porous material, but also a hot point in the field of the development of new material. Ceramic particle reinforced aluminum matrix composite foams is a kind of new metal foams. Some investigators paid attention to the aluminum matrix composite foams reinforced by ceramic particles due to the intrinsic potential of particles to improve the comprehensive property of foams. Throughout the research and development of metal foams in the whole world, most works aimed at the aluminum foams and the aluminum alloy foams, and the researches about SiC particles reinforced aluminum matrix composite foams were extremely limited. Only few investigations on quasi-static compressive property, damping and sound absorption property of aluminum matrix composite foams were carried out, and there were hardly the researches on the dynamic compressive property of aluminum matrix composite foams and the bending property of the sandwiches with aluminum matrix composite foams core. However, the researches on the damping property were limited to the influence of pores, and the effects of the volume fraction and diameter of reinforced particles on the damping property were not studied. Up till now, the reports about the component optimization to improve the comprehensive property of SiC particle reinforced aluminum matrix composite foams and control the shape, size and uniformity of pores were still less. In China, the researches about SiC particle reinforced aluminum matrix composite foams were started relatively late, and they are only in initial stage now. Therefore, it has theoretical and practical significance that deep and systemic researches on this kind of foams are carried on in order to enrich the fabrication process of foams and promote the development and extensive application of metal foams.Based on the insufficiencies of the researches on SiC particle reinforced aluminum matrix composite foams, the following researches were carried out in this dissertation:Firstly, SiC particle reinforced ZL104 composite foams (SiC_p/ZL104 composite foams) were successfully fabricated by the direct foaming of the melt. The porosity, the average diameter of pores, and the volume fraction of SiC particle in this composite foams can be controlled. The effects of the foaming temperature, content of the foaming agent added, stirring parameters, holding time, and cooling ways on the fabrication of foams were systemically analyzed. The optimized technological parameters were obtained.Secondly, the quasi-static compressive properties of SiC_p/ZL104 composite foams were tested. The systemic researches on the effects of SiC particle, the average diameter of pores, and the relative density on the quasi-static compressive properties and energy absorption ability of SiC_p/ZL104 composite foams were firstly performed. The experimental results and the deformation mechanism of the composite foams were explained in theory. A theoritical analysis was carried out to show the relationship between the yield strength of SiC_p/ZL104 composite foams, the relative density of SiC_p/ZL104 composite foams, and the volume fraction of SiC particles. And the efficient paths to improve the energy absorption ability were suggested. The results are as follows:1. The deformation mechanism of SiC_p/ZL104 composite foams is layer by layer under the quasi-static loading, which leads to the long collapse plateau region in stress-strain curves. The collapse plateau region of SiC_p/ZL104 composite foams exhibits serrate undulation, which differs from that of ZL104 foams. SiC_p/ZL104 composite foams are of well compressive property. The compressive deformation course of SiC_p/ZL104 composite foams involves three stages: the linearly elastic deformation region, the collapse plateau region, and the densification region.2. The yield strength of SiC_p/ZL104 composite foams with different sizes of SiC particles increases with the increase of the volume fraction of SiC particles when the relative density and pore diameter are identical. But the yield strength of SiC_p/ZL104 composite foams with the identical volume fraction of SiC particles increases with the decrease of the size of SiC particles.3. The yield strength of SiC_p/ZL104 composite foams increases with the decrease of pore diameter when the relative density, the size and the volume fraction of SiC particles are identical.4. The yield strength and flow stress of SiC_p/ZL104 composite foams also increases with the increase of the relative density when the pore diameter, the size and the volume fraction of SiC particles are identical.5. The equation between the yield strength, the relative density, and the volume fraction of SiC particles in SiC_p/ZL104 composite foams under the quasi-static loading was established.6. The energy absorption ability and energy absorption plots of SiC_p/ZL104 composite foams with different relative densities, pore diameters, and the volume fraction and size of SiC particles were investigated. The results show that the energy absorption ability of foams mainly lies on the height and length of the collapse plateau region. Therefore, the factors, which affect the height and length of the collapse plateau region, will have effect on the energy absorption ability of foams. Choosing small size of SiC particles as reinforced material, thinning pore diameter, and increasing the relative density of SiC_p/ZL104 composite foams with the same volume fraction of SiC particles can improve the energy absorption ability under the quasi-static loading. Or when other characteristic parameters are identical, increasing the volume fraction of SiC particles can also improve the energy absorption ability under the quasi-static loading.Thirdly, Split Hopkinson Pressure Bar (SHPB) system was used to test the dynamic compressive property of SiC_p/ZL104 composite foams. The systemic researches on the effects of the strain rate, the average diameter of pores, the relative density and SiC particle on the dynamic compressive properties and energy absorption ability of SiC_p/ZL104 composite foams were firstly performed. The influencing rules of the composite foams were explained in theory with corresponding structure models. Moreover, the strain rate sensitivity of SiC_p/ZL104 composite foams was analyzed. The results are as follows:1. The stress-strain curves of SiC_p/ZL104 composite foams under dynamic loading are similar to that of SiC_p/ZL104 composite foams under quasi-static loading. But the yield strength exhibits remarkable variety. Moreover, with the increase of the strain rate, the strain hardening occurs. The main reason is the intrinsic strain rate sensitivity of SiC_p/ZL104 composite and the effect of micro-inertia on the strain rate sensitivity. SiC_p/ZL104 composite foams is a kind of strain sensitive material, and its strain sensitivity parameter is higher than those of aluminum foams and pure aluminum. The yield strength of SiC_p/ZL104 composite foams with identical characteristic parameters increases with the increase of the strain rate. Further more, the increase speed of the yield strength of SiC_p/ZL104 composite foams under high strain rate is higher that under low strain rate.2. The effects of pore diameter (1-2.5mm) and sizes of SiC particles (5-28μm) on the dynamic compressive property of SiC_p/ZL104 composite foams with the same relative density were not obvious. With the increase of the relative density and the volume fraction of SiC particles, the dynamic yield strength and flow stress of SiC_p/ZL104 composite foams increase markedly as compared with those under the quasi-static loading.3. The energy absorption ability and energy absorption plots of SiC_p/ZL104 composite foams with different strain rate, relative density, pore diameter, and size and volume fraction of SiC particles were investigated. The results show that the energy absorptivity of SiC_p/ZL104 composite foams increase in different extent with the increase of the strain rate, the relative density, and the volume fraction of SiC particles, and the decrease of the size of SiC particles. The change of the energy absorptivity of SiC_p/ZL104 composite foams is unobvious with pore diameter between 1mm and 2.5mm. Fourthly, sandwiches with SiC_p/ZL104 composite foams core in three layers, five layers and seven layers were made for the first time. Three-point bending tests of the sandwiches with SiC_p/ZL104 composite foams and ZL104 foams core were performed. The results are as follows:1. P-δcurves of the sandwiches involve three stages: the linear region, the elastic-plastic region and the unsteady region. Three failure modes of the sandwiches under three-point bending are panel-yield, core-yield and bonding-damage. The theoretical value of the bending stiffness of the sandwiches is slightly greater than the experimental value. The experimental results coincide with the results calculated with limit load formulas.2. The bending stiffness of the sandwiches with SiC_p/ZL104 composite foams core increases in different extent with the increase of the relative density, thickness of surface panel, thickness of core material, and the volume fraction of SiC particles, and the decrease of the size of SiC particles. The bending stiffness of the sandwiches with SiC_p/ZL104 composite foams core is greater than that of the sandwiches with ZL104 foams core in the same relative density.3. The failure modes of the multilayer sandwiches are the combination of local indentation, core-shearing yield and bonding-damage.Finally, the damping properties of SiC_p/ZL104 composite foams at room temperature were tested. The damping mechanism of SiC_p/ZL104 composite foams was analyzed. The effects of the pores and SiC particles on the damping property of SiC_p/ZL104 composite foams were investigated. The results are as follows:1. The damping property of SiC_p/ZL104 composite foams in a given pore diameter at room temperature shows that the loss factor nonlinearly increases with the increase of the porosity, but the increment extent becomes more and more little. The loss factor of SiC_p/ZL104 composite foams increases gradually with increasing volume fraction of SiC particles and decreasing size of SiC particles.2. When other characteristic parameters are identical, the damping property of SiC_p/ZL104 composite foams at room temperature increases with the decrease of the pore diameter. Trend of decrease weakens gradually. 3. When other characteristic parameters are identical, the damping property of SiC_p/ZL104 composite foams increases gradually with increasing thickness of the foams.4. The damping mechanism of SiC_p/ZL104 composite foams was investigated. When other characteristic parameters are identical, the damping property of SiC_p/ZL104 composite foams at room temperature is better than those of Al foams, SiC_p/ZL104 composites and ZL104 alloy due to the existence of pores in SiC_p/ZL104 composite foams and high density dislocation.
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