Study on surface strengthening and mechanical properties of aluminum alloy manipulator of logistics robots

To improve the hardness and tensile properties of aluminum alloy for logistics robots' mechanical arms, a single WC-Ni cladding layer was prepared. Its morphology and hardness were compared and analyzed, and the tensile samples were prepared by a multicladding layer on the surface of the tensile rod. The results showed that with laser power increasing, the height of a single cladding layer first increased and then decreased, the depth of the molten pool increased, the width of the cladding layer increased, and the dilution first decreased and then increased. When the laser power was 1.0 kW, the dilution rate of a single cladding layer reached the minimum, the bonding strength with the matrix reached the maximum, and the metallurgical bonding effect was the best. There were new phases W₂C, NiAl, Ni₃Al, M₇C₃ and M₂₃C₆ in the cladding layer, the top of which was composed of cellular crystals. In the middle there were a large number of WC particles, and M₇C₃ and M₂₃C₆ precipitated phases. The bonding zone was mainly composed of directional dendrites. The HV hardness of a single cladding layer first increased and then decreased, and the maximum value was 960.6. The tensile strength and elongation of the multicladding layer were 313 MPa and 1.3% respectively, which were 21.8% higher and 27.8% lower than those of the matrix. The tensile fracture between the multicladding layer and the substrate was smooth.