摘要: |
Military tracked vehicles are equipped with rubber track pads or endless-band rubber track to reduce noise and wear, improve traction, and reduce damage to road surfaces. Historically, field performance of the rubber components has been poor. ARL initiated an effort to develop improved rubber compounds for the track pads on military tracked vehicles. Following an extensive series of rubber formulating, mixing, laboratory testing, and field testing, an elastomeric compound coded NBR-12 was developed. This compound was based on a highly saturated nitrile rubber or hydrogenated acrylonitrile-butadiene rubber (HNBR) reinforced with a small particle size carbon black, grafted with zinc methyl methacrylate domains, and vulcanized with a peroxide. The NBR-12 material provided more resistance to heat, abrasion, cutting, chipping, and flex fatigue compared to all other commercial track pad materials evaluated in this program. This material provided a 2- to 3-fold increase in service life of pads on the M-60, M-1, and Counter Obstacle Vehicle. During the late 1990s, 2 of the critical ingredients for NBR-12 (Z Max MA and MPC black) became unavailable. Additional work is needed to replace these ingredients. Natural rubber compounds provided excellent tear properties but lacked the necessary abrasion resistance needed for track pad applications, and were better suited for bushing and road wheel applications. Tri-blends of the polymers styrene butadiene rubber, natural rubber, and polybutadiene rubber exhibited potential for future consideration as candidate track pad compounds. |