Seal Characteristics Analysis And Experimental Research On Metal Rubber Seal Under High Temperature

The Metal Rubber(MR)seal has a series of excellent properties that cannot be compared by other rubber seals, such as high pressure, corrosion and radiation resistance, strong bearing capacity, the large working range and aging resistance. It is significant for applying it in the special working environment such as aviation aerospace, defense and armament working condition. However, the MR seal has the problems of the difficult manufacturing process, the less research both in the theoretical and experimental aspects in our country. So the thesis will do some research in these aspects and the specific contents includes:With respect to the manufacturing problems of the MR seal, design the milling process to complete the pipe-opening and the pipe-bending process and manufacture the corresponding equipments. Manufacture the MR seals that coated by stainless steel using the equipments for the sealing experiments in the high temperature.Based on the elastic contact mechanics theory and percolation theory that put forward by Persson B N J, MR seal leakage prediction model is established and the sealing mechanism is analyzed from the microscopic angle of the surface roughness morphology of the seal-substrate coupling interface. Based on the finite element simulation method, the method of realizing the leakage prediction model is put forward. Through the mechanical properties experiment, mechanical properties of the MR such as Elastic Modulus, Poisson’s Ratio parameters are studied and the empirical formula of the seal leakage rate of MR is deduced. Combined with the working condition of experiments, the critical magnification result and the leakage rate values are given of a structural parameters of the MR seals applied in the experiments. The contrast which provides reference to predict the sealing performance of MR seal between theoretical value and experimental value under certain pressure and temperature conditions is conducted and as a result, they are basically both in line with each other.The experiments of the MR seals with different relative density are conducted and the influence of the relative density to the sealing performance is researched under different pressure and temperature conditions. The leakage rate laws changing with the temperature and pressure of different relative density of MR seal are obtained under different pressure and temperature, which provide certain guide for the practical engineering application of the MR seal; The contrast experiments with Fluorine rubber, NBR O-ring, NBR rectangle ring and spring self-tightening type metal C ring under different pressure and temperature conditions are conducted. The more applicable temperature and pressure conditions and sealing performance advantages of MR seals are studied.