| High volume fraction SiC particle reinforced aluminum matrix composites have been widely used in aviation, aerospace, electronic packaging and other fields because high stiffness, low thermal expansion coefficient and well dimensional stability. However, with the increase of the reinforcement volume fraction, the material weldability will decreased substantially. Cracks and needle-like Al4C3 formed between the SiC and Al will seriously reduce the mechanical properties of the weldIn this paper, high volume fraction (45%) SiCP/2024 aluminum matrix composite was jiont using Ti-6Al-4Vfoil as intermediate material by laser. In-situ reaction between particles and Ti make the welding process easy. The weld strength was tested and the fracture behavior, phase structure and weld pool crystallization process were deeply studied.The thickness and laser power have great effect both on the interface morphology and bead formation. Ti-6Al-4V silces of different thickness (0.3 1.0mm) were selected to join the base mental. The results showed there is no reaction layer with thinner Ti-6Al-4V foil (d≤0.3mm), Fracture behavior of joints occurred in the weld center. Tensile strength were higher than the joint with thicker Ti foils, The greatest tensile strength was 125.6Mpa. There is a significant interface reaction layer between the weld and base metal with thicker Ti-6Al-4V foil (d≥0.5mm). The joints were broken at the interface with lower tensile strength.SEM, EDS and XRD were used to analyze the microstructure of the weld. The weld was constituted mainly by Ti5Si3, AlTi3 and TiC with crystallization order of TiC→Ti5Si3→AlTi3. The growth mechanism of TiC was analyzed which was the product of the in-situ reaction... |
PDF Full Text Request