Influence of carbon pre-coating prior to laser deposition on rolling contact fatigue of gray cast iron
- PDF / 1,289,300 Bytes
- 12 Pages / 584.957 x 782.986 pts Page_size
- 66 Downloads / 202 Views
Zhou The Department of Mechanical and Automotive Engineering, Jilin University, Changchun, Jilin Province 130025, People’s Republic of China
Ruoyu Zhao The Key Lab of Automobile Materials, The Ministry of Education, Jilin University, Changchun, Jilin Province 130025, People’s Republic of China
Haifeng Zhang The Department of Mechanical and Automotive Engineering, Changchun University, Changchun, Jilin Province 130028, People’s Republic of China
Wanshi Yang, Hong Zhou, and Peng Zhanga) The Key Lab of Automobile Materials, The Ministry of Education, Jilin University, Changchun, Jilin Province 130025, People’s Republic of China
Luquan Ren The Key Lab of Terrain Machinery Bionics Engineering, The Ministry of Education, Jilin University, Changchun, Jilin Province 130025, People’s Republic of China (Received 23 May 2015; accepted 24 August 2015)
This work presented a study on the improvement of laser surface treatment on rolling contact fatigue resistance of gray cast iron. Sample surface covered with carbon powder was coupled with localized treatment by high-energy laser beam—a process defined as “laser cladding (LC).” With this method, the optimum precoating thickness was experimentally studied. Compared to the region treated by laser remelting, the crystal in LC region was finer, more compact, and uniform. Mechanical property testing showed not only high micro-hardness of LC region, but also improved tensile and compressive resistance of treated material. Fatigue wear tests and thorough analysis of fatigue detects suggested that LC treatment significantly improved fatigue wear resistance (FWR). Improved FWR was likely facilitated by delayed initiation and propagation of cracks, as well as the reduction of contact stress on substrate. Additionally, formations of fatigue defects on sample surface were thoroughly discussed.
I. INTRODUCTION
Contributing Editor: Yang-T. Cheng a) Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2015.288
stress, can be modified by embedding high hardness steel into GCI substrate to benefit from the combined properties of both materials. Joining short steel pieces together is a complex process and formation of junctions makes defects more prone to occur. At this background, a facile and economical method of improving the fatigue wear resistance (FWR) of GCI is urgently necessary. Previous research5 has suggested that GCI performs satisfactorily under RCF after surface treatment, though stress concentration is likely to be raised at the flake graphite tips, creating natural defects. However, abrupt discontinuity in the hardness between the coating and matrix is determined a primary cause of poor adhesion, leading to shedding and splitting of the coatings for this technology. An optimized method of surface treatment that successfully improves FWR should be explored in effort to remedy this. Over billions years of natural selection and evolution, biological structures have gradually adapted to their living
3104
Ó Materials Research Society 2015
Gray cast iro
Data Loading...
