Papers by Author: Lu Cai Wang

Abstract: Foamed aluminum has been recently developed as one of new structure functional materials due mainly to its excellent properties such as energy absorption property. It is significant to investigate the compressive behavior and energy absorption property of foamed aluminum under the condition of static and dynamic loading. The compressive deformation behavior of foamed aluminum with open pore structure was experimentally studied and the effects of the porosity, the type of materials, the pore size and the sample size were discussed in detail by means of the orthogonal experiments. The results showed that the type of materials had the most evident influence on the compressive property of foamed aluminum among the factors investigated, and that the size effects of the experimental results were observed.

Abstract: Foamed aluminum has been applied in many fields due mainly to its excellent properties. The tensile deformation process and characteristics of foamed aluminum with closed-cell were studied in this paper and the deformation mechanisms were discussed. The results show that foamed aluminum fractured without necking. The tensile stress-strain curves have similar characteristics, the linear elasticity at a low stresses followed by plastic yielding, strain hardening and rupture, which has obvious difference with compression stress-strain curve. The fracture mechanism is neither brittle fracture nor plastic fracture. The defects existed in foamed aluminum interior have important influence on tensile property.

Abstract: The aluminium foam is reinforced by compositing ZrO₂ ceramic balls with high hardness. The production process includes preparing precursor using NaCl particles and ZrO₂ ceramic balls, infiltrating molten aluminium into precursor and cleaning NaCl particles. The defects presented during the process make the structure inhomogeneous and influence the performance of aluminium foam composite. The defects consist of inner and surface shrinkage caused by insufficient infiltration and inhomogeneous distribution of ZrO₂ ceramic balls in the composite. By analyzing the forming mechanism, offering right control of process and choosing correct parameters, the sound aluminium foam composite was prepared. The optimum value of pouring temperature, preheating temperature of die and particles and the suction was determined as 740°C-760°C, 480°C-500°C and -0.04Mpa, respectively. The composite has the structure with 0.8-1.2mm pore size, 60-70% porosity and ZrO₂ ceramic balls of 40 percent by volume. The research makes a basis for the application of the new aluminium foam composite.

Abstract: The compression behavior of open-cellular Aluminum foams was simulated using DEFORM-3D software. The structures of regular tetrahedron, octahedron and tetrakaidecahedron (Kelvin) model were developed separately. Simulation results show that the models have similar compression behavior. Then load-time curves and strain-stress curves have similar characteristics, the linear elasticity at low stresses followed by a long collapse plateau, truncated by a region of densification in which the stress rises steeply. Compared with experiment, the platform stress and the Young’ model of the Kelvin mold have good consistency within the error range.