Wear resistance and wet skid resistance of composite bionic tire tread compounds with pit structure

This work was aimed to introduce the bionic non-smooth structure of pits into compound preparation by referring to the bionics concept. Four types of highly wear-resistant tire tread compounds (A1, A2, A3, A4) and 4 types of highly wet-skid-resistant tire tread compounds (B1, B2, B3, B4) were made by adjusting the rubber contents and changing the parts per hundreds of carbon black and silica. According to the characteristics of the designed bionic structures and tire treads, A2 and B3 were combined to manufacture composite bionic structured tire tread compounds (C1, C2, C3, C4) through pressured and heated vulcanization. It was found BR showed higher wear-resistance and lower wet-skid resistance than SBR. With the increasing dosages of carbon black and silica, the wear-resistance was first enhanced and then weakened, but the wet-skid resistance was gradually reduced. The wet-skid resistance of tire tread compounds was associated with the hardness and roughness of the friction surfaces, and was improved when the roughness and hardness decreased. Due to the difference in wear-resistance between A2 and B3, pits were formed after wearing, which strengthened the wear-resistance and wet-skid resistance of the tire tread compounds. Compared with A2, the wear-resistance of C2 was increased to the largest extent of 0.98%, but the increasing magnitudes of wet-skid resistance were not significantly between C3 and C4, and the highest increment magnitudes on the diamond piece surface were 20.9% and 21.1%, respectively. The coupling functions of the bionic composites prove the feasibility and practicability of bionic abrication, providing a new way to improve the compound properties.