Product Code: PIC2008_1204

Mechanism Analysis on Dry-Friction Abrasive Wear Resistance of Particulate Reinforced Mmc Coatings by Laser Deposition for Corrugated Rollers
Authors:
Zhaoyong Qian, Tsinghua University, Dept of Mechanical Engineering; Beijing Peoples Republic of China
Minlin Zhong, Tsinghua University; Beijing Peoples Republic of China
Wenjin Liu, Tsinghua University, Dept of Mechanical Engineering; Beijing Peoples Republic of China
Mingxing Ma, Tsinghua University; Beijing Peoples Republic of China
Chaofeng Wu, Tsinghua University; Beijing Peoples Republic of China
Dongye Zhang, Tsinghua University; Beijing Peoples Republic of China
Presented at PICALO 2008

Corrugated roll is a key component for production of corrugated paper for packaging industry. Corrugated rolls (CR) suffer severe dry friction abrasive wear of the paper during production. Hardfacing of coating with good abrasive wear resistance on CR by laser deposition is a promising technique to improve the lifetime of the CR. Previous research indicates that crack-free coatings with particulate reinforcement can be deposited on corrugated rolls with optimized composition and processing parameters. The laser deposited particulate reinforced MMC (PR-MMC) coating shows a hypoeutectic structure consisted of proeutectic austenite dendrites and eutectic matrix, in addition to a large amount of composite carbides precipitated in-situ during solidification and homogeneously distributed in the metal matrix. However, the mechanism on abrasive wear resistance in severe dry-friction wear conditions in corrugated paper production needs to be investigated. The mechanical and tribological behaviors of phases in the PR-MMC were investigated separately by means of nanoindentation test and nanoscratch test. As a result, the nanohardness, elastic modulus and tribological coefficient are obtained. The fracture toughness properties of the composite carbide particles precipitated in-situ and the tungsten particles used in experiments are comparatively investigated. The precipitated carbide particles show better fracture toughness and higher nanohardness than the tungsten particles. Tribological tests for as-deposited and tempered 200, for 1h coatings were performed on a grain-abrasion testing machine reconstructed from an automatic buffing machine simulating the working condition of CR. The tempered coatings have the best abrasive wear performance compared with as-clad and laser phase transformation hardened coatings. The main mechanism on good dry-friction abrasive wear resistance of the PR-MMC was attributed to the homogeneously distributed carbides particles, which inhibits the ploughing by means of smashing and breaking up the invading particles to lose their cutting function. The results also indicate that the features of particles (size, proportion and distribution) are important factors on abrasive wear resistance.