Reserch On Mechanical Properties Of Ni60 Laser Cladding Layer

With the extensive application of laser cladding technology, mechanical properties of laser cladding surface have received more and more attention. Laser cladding technology is mainly used for processing material surface. Compared with conventional materials, laser cladding surface can not be used with traditional mechanical tests to ger their materials properties. The elastic modulus and hardness of materials can be calculated by the load-displacement curve obtained by nanoindentation test using empirical formula, but the plastic properties of materials(stress-strain curve) can not be measured. Therefore, the mechanical properties of the cladding layer will be studied by combining nanoindentation techniques and finite element simulation in the thesis.Finite element model based on nanoindentation testing process was established after nanoindentation test of Ni60 laser cladding layer. Load-displacement curves were obtained with corresponding element types, material properties, boundary conditions and load settings. Material properties should be set in the finite element simulation in advance, which can be obtained from the nanoindentation tests except for plastic properties. With changing material properties constantly, mechanical properties of Ni60 laser cladding layer corresponding to the indentation position were measured when the load-displacement curve of simulation coincided with the experimental curve.On this basis, the finite element simulation model based on Ni60 laser cladding microstructure was established. Moreover, mechanical properties of each phase on the cladding layer were analyzed. According to compression testing process simulation of multiphase materials of Ni60 laser cladding layer, the stress-strain curve of the cladding layer was studied.Mechanical properties of H13 steel were also determined with the method of combining nanoindentation technique and finite element simulation, from which got the stress-strain curve of H13 Steel. On the other hand, stress-strain curves of H13 steel under experimental conditions were obtained from the conventional tensile tests. The reliability of the method was verified, by comparing the experimental results and the simulation results.