Wear Resistance Study of Bionic Pitted Ni Cladding Layer on 7075 Aluminum Alloy Drill Pipe Surface

To enhance the lifespan of drill pipes and minimize wear, this study introduces a bionic structure model inspired by the pit shape structure found in the dung beetle's abdomen. The stress distribution and wear of bionic pitted structure and ordinary structure are simulated by finite element software. The findings revealed that the bionic structure significantly improves stress distribution, resulting in an impressive 81.3% increase in lifespan. Subsequently, the surface of the 7075 aluminum drill pipe was coated with Ni powder by a laser cladding system. Wear tests were conducted to analyze the wear and surface damage behavior of the cladding layer. The microstructure, composition, and microhardness of the cladding layer were measured and observed. The results showed that the cladding layer was mainly composed of Al3Ni2 and had high hardness. Additionally, a transition region exists between the cladding layer and the substrate, comprising relatively low hardness Al, thereby enhancing the drill pipe's ability to withstand alternating loads. Furthermore, the bionic structure possesses the capability to store particles, effectively reducing the occurrence of abrasive wear and increasing the lifespan by 70.0%.