Study on the Mechanical Properties of Metal Rubber Inner Core of O-Type Seal with Large Ring-to-Diameter Ratio

In view of the problems of ordinary rubber seals, such as high- and low-temperature resistance, easy aging, and insufficient load-bearing performance, O-type metal rubber seals with large ring-to-diameter ratio were prepared by the cold stamping method using stainless steel wire as raw material. The effects of heat treatment and porosity on the compression and tensile properties of test samples were investigated. Under uniaxial compression testing, it was found that the test sample had typical hysteresis characteristics, and the loss factor and energy dissipation of the sample with the same size and different porosity increased with the decrease of porosity. The loss factor and energy dissipation of the heat-treated sample were lower than those of the untreated sample. Thus, the smaller the porosity, the greater the change of loss factor and energy dissipation. Under uniaxial tensile testing, obvious stage changes were found during the tensile process, which included a linear elasticity stage, the formation and development stage of wire breakage, the one-by-one fracture stage of wires, and the complete failure stage of the sample. The yield strength, ultimate tensile strength, and modulus of elasticity of four samples with different porosity were measured, and it was found that the three parameters increased with the decrease of porosity. Moreover, the thermal treatment conductivity increased with the decrease of porosity. The aforementioned three parameters were generally increased. This indicated that metal rubber materials have good mechanical properties under high-temperature environments, which effectively solves the problem of vulnerability to aging and failure of ordinary rubbers under normal working conditions and has strong practical engineering significance.