Research On Mechanism In Laser Rapid Prototyping Process Of Titanium

As direct metal rapid prototyping can fabricate metal part with complex shape rapidly, it has been paid more and more attention to by enterprise and research institutes. The key to achieve the control with the property of part lies in the research to the property of the part. Temperature is regarded as core element in RP due to its decisive effect to the property of part. The effect of technological parameter on temperature field can be acquired by the simulation of temp field using finite element method. And the process of microstructure evolution of the part manufactured by RP can be acquired by coupling FE and cell automation.In this paper, the processing mechanism of rapid prototyping and the evolution mechanism of microstructure are researched. Also, the model of thermodynamics and microstructure evolution are established. In the last, the temperature field and microstructure in rapid prototyping process are simulated and studied by means of modern computer technology. The main research works in this paper are listed as follows:(1) Based on a large number of literatures in home and aboard, the research status and the growing trend including domestic and foreign research are full-scale summarized. In the meantime, the necessity and significance of the research are illustrated.(2) Absorption to laser of metal materials is researched and solution method of cladding power is determined. The thermal behaviors in formation process are described. The temperature field is reviewed by the aid of the thermodynamic module of ANSYS. The effect of crucial parameter on temperature field is analyzed.(3) The mechanism of nucleation and growth of grain is illustrated, which provides theoretical basis for the simulation of microstructure. The feasibility and superiority of cell automation in the simulation of microstructure are demonstrated.(4) The cell automation model used to simulate microstructure evolution is established based on the mechanism of nucleation and growth of grain. In this model, the preferred orientation is realized.(5) The macro and micro coupled algorithm is discussed. The microstructure evolution of part fabricated by rapid prototyping is simulated by coupling FE and cell automation model established previously. And the result of simulation is studied. A graphic user interface is developed to gain control of the simulation.