Search Results

This study aimed to visualize crack initiation and propagation of rubber at low temperatures. Typical fatigue behavior such as cracking at only the compressed part of rubber products like dustcovers during oscillation tests at ultra-low temperatures have been reported [1]. Rubber products are usually used at temperatures where good rubber elasticity can be obtained. However, in some cases, they are used near glass transition temperatures at which rubber elasticity is poor. Fatigue failures of rubbers generally occur due to existing defects in the rubber material, and rubber tends to fracture easily near glass transition temperatures due to cracking on the surface of the compressed side of the rubber. The observation of the crack initiation process of rubber is difficult at low temperatures because the fracture patterns on rubber disappear when elasticity is recovered at room temperature.

Several number of ball joints are used in the suspension system. For these ball joints, rubber dust covers are used in order to maintain sufficient lubrication and protect the ball joint from contaminants such as water and dusts. In recent years, the number of breakage or grease leakage of the dust cover used under ultralow temperature is increasing with the growth of automobile selling in developing countries. In this research, we have studied the mechanism of dust cover breakage under ultralow temperature by focusing on the low temperature behavior of a rubber material.