*Article* **E** ff**ects of Laser Melting Distribution on Wear Resistance and Fatigue Resistance of Gray Cast Iron**

**Haiyang Yang 1, Ti Zhou 2,\*, Qingnian Wang 1 and Hong Zhou 3**


Received: 6 July 2020; Accepted: 14 September 2020; Published: 17 September 2020

**Abstract:** The coupling bionic surface is generally prepared by laser melting on the surface of a gray iron brake hub, which can allow the brake hub to achieve excellent wear resistance and fatigue resistance. The designs of most previous experiments have been based on independent units that were uniform in their distribution patterns. Although some progress has been made in the optimization of cell features, there is still room for further improvement with respect to bionics and experimental optimization methods. Here, experiments on units with non-uniform distributions of di fferent distances were used to rearrange and combine the bionic elements. This paper is that the original uniform distribution laser melting strengthening model was designed as a non-uniform distribution model, and the heat preservation and tempering strengthening e ffect of continuous multiple melting strengthening on the microstructure of the melting zone is discussed. The mechanism of crack initiation and the mode of crack propagation were analyzed. The relationship between the internal stress in the melting zone and the crack initiation resistance was also discussed. In this paper, the mechanism of di fferent spacing distribution on the surface of gray cast iron by laser remelting is put forward innovatively and verified by experiments, which provides a solid theoretical basis for the follow-up industrial application.

**Keywords:** laser melting; biomimetic model; brake pads; surface wear
