Study On Theory Force Model Andsimulation Of High Temperature Friction Drilling 1Cr18Ni9Ti

Austenitic stainless steel is widely used in aeronautics, astronautics, chemical, petroleum, construction and food industries. However, austenitic stainless steel is a kind of difficult-to-machine material due to its severe plastic deformation, low thermal conductivity and serious work hardening. High temperature friction drilling is a non-traditional drilling method. Compared to traditional drilling, friction drilling has the advantages of fast, high quality, green and environmental. High temperature friction drilling can solve the problem of drilling difficulties in austenitic stainless steel 1Cr18Ni9 Ti. This paper mainly focus on the friction properties, force model, process simulation and tools optimize of friction drilling. It has both important theoretical significance and extensive application value.Based on the state of arts of the friction drilling technology, friction theory and experiment rules are studied to lay the foundation for the force model. The equivalent platform based on CA6140 lathe is developed, and the friction properties of 45 steel and 1Cr18Ni9 Ti in different load and speed are tested to reveal laws. The formula of friction coefficient is proposed to provide the basis for the following works on force model and simulation model.Based on the special tool, the force model of each process step in friction drilling is developed. Processing stages division is based on geometrical parameters of tools. Force model of each processing stage for prediction of the friction drilling force is developed using friction property formula.The machining process of high temperature friction drilling 1Cr18Ni9 Ti is studied by ABAQUS, which is a commercial finite element analysis software. The 3D model of tool and workpieces are meshed after imported into the finite element software. Material constitutive models of tool and workpieces are developed. The process simulation model is developed based on the processing conditions and reasonably set boundary conditions. The stress distribution and deformation of the workpieces are investigated to reveal the deformation mechanism. The prediction of drilling force provides the basis for tool optimization.Force model and finite element simulation model are used to optimize the 1Cr18Ni9 Ti friction drilling tool. The optimum parameters of the tool are determined by analyzing the stress distribution and deformation of nine modules with different cone angle and contact area. This research provides a theoretical basis for the high temperature friction drilling technology. Besides, it can be used for other difficult-to-machine materials.The innovations of this paper are that the friction coefficient in friction drilling is considered more carefully, then force model and simulation model of friction drilling are developed. Based on this, an optimization technology of tool geometry which combines the force model with the simulation model is proposed. This technology is more efficient and more cost-effective than the traditional test optimization method.