| A blisk is a novel component for a new generation of advanced aero-engine, which is achieved with structure innovation and technology across. The dynamic airflow and performance of aero-engine is impacted by the surface quality and profile precision of blisk. At present, the linear friction welding, semi precision milling, fine milling, precision grinding and shot peening, are the main processing technology for the blisk. There are many research works for the grinding technology of blisk at home, but most of them are still stayed in the experiment, so the method of polishing with hand is still the main grinding process for the blisk at the current, not only with high labor intensity and low efficiency, but also the surface is easy to burn, surface quality, profile precision and consistency are difficult to guarantee. This shows that the existing blisk grinding method is not adapt to the demand of mass production of advanced aero-engine, and the overall level of aero-engine is restricted in a certain extent. Therefore, a new method of open-loop belt grinding is proposed by the process characteristics of blisk, and then, the method of open-loop belt grinding for blisk without interfering grinding is analyzed, finally, the open-loop belt grinding experiment for blisk is completed. The main contents and conclusions of this paper are as follows:(1) A new method of high efficiency grinding with belt grinding based on cutting optimization. Firstly, the equation of belt grain wear is established by the single particle model and energy theory equation, at the same time, the impact of grain wear on the material removal and surface roughness is analyzed for the different materials, which including titanium alloy, nickel alloy and stainless steel, with the method of single factor experimental, and then the principle of high efficiency grinding with belt grinding based on cutting optimization is put forward. Secondly, the renew grinding movement is analyzed based on the principle of Archimedes spiral line, and then, the curvature reciprocating and renew moving or after renew moving of is described according to the characteristics of the new method. Finally, the method of second air floatation is used to the design of the belt grinding system, and the layout of wheels are designed, at last, the belt grinding head is developed.(2) The efficient material removal mechanism and parametric model for titanium alloy with open-loop belt. Firstly, the parametric model of full life-cycle material removal is established through the analysis of traditional material removal rules of belt grinding. Secondly, the method of orthogonal experiment with nine-factors and four-levels is used for planar and cylindrical shape titanium alloy workpiece with the open-loop belt grinding, the parametric model of full life-cycle material removal for titanium alloy is obtained with multi element linear least squares regression, and then the model is verified by the significant level testing. Finally, the influence of grinding parameters, grinding conditions and new type of motion on the materials removal rule of titanium alloy with belt grinding is analyze with the method of single factor experiment, at last, the accuracy of the prediction model was verified.(3) The open-loop belt grinding process and interference free motion planning method for the blisk. Firstly, the open-loop belt grinding process for blisk is analyzed from the top leaf, surface, edge, air-flowing surface, the method of force adaptive is proposed to realize precision grinding, and then, six-axis grinding and optimal contact method are also analyzed. Secondly, the interference characteristics of open-loop belt grinding for blisk is analyzed from the structure, surface and feeding movement based on the traditional interference characteristic. Finally, the vector control method is analyzed from interference free motion planning for the the top leaf, surface, edge, air-flowing surface.(4) Experimental research on the open-loop grinding for the blisk. Firstly, the experimental CNC belt grinding device and experiment method are introduced. Secondly, the surface integrity of blisk are analyzed respectively from surface roughness, surface residual stress and surface morphology, at the same time, the profile precision is analyzed respectively from surface precision, edge precision and root accuracy. Finally, the consistency evaluation method is introduced, and then, the comprehensive analysis consistency is analyzed from surface integrity and profile precision.The results show that the surface roughness is less than 0.25 ?m, defects and the transition region of knife milling were completely eliminated, the surface texture was fine, the surface residual stress ranged from-200 to-400 MPa, the Bland Altman values consistency is significantly improved by 50% and 80%. |
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