Equipment Optimized Design And Process Study For The Variable Section And Large Size Gas Pipe In ECM

Gas pipe is the key component of aerospace engine thrust chamber. It is a kind of large size and variable cross-section irregular bend, and its material is high temperature alloy. When traditional machining method used to weight reduction and formation of the gas pipe, the machining efficiency is low and there are many defects on the workpiece surfaces, such as micro cracks and residual stress. Electrochemical machining (ECM) is not restricted by the hardness, strength and toughness of material and the complexity of the processing surface of workpiece. ECM has the characteristic of high machining efficiency and good surface integrity, therefore it is especially suitable for processing the gas pipe.According to the principle of ECM technology, the internal and external half pipe machining process system is set up based on DJK3235 machine. Combined with the structure characteristics of the internal and external half pipe, the function requirements of the equipment are analyzed. The equipment, suitable for the internal and external half pipe, are developed. Finite element static analysis was carried out on the equipment by using the ANSYS workbench. The reliability of the equipment is improved after the weak links are enhanced.The related processing parameters that match with the experiments for gas pipe in ECM are designed according to the forming regulation of ECM. The processing parameters combination is processing voltage 18V, feed rate 0.3mm/min and 20% NaNO3 electrolyte. The technology tests of ECM gas pipe are completed based on the processing system. Regarding the wall thickness of workpiece as machining accuracy as experimental evaluation index, the experiments’ data is analyzed, and the cathode modifications are completed. The qualified products are obtained when the gas pipes are processed by the modified cathodes.