Research on the Improvement Effect and Mechanism of Micro-Scale Structures Treated by Laser Micro-Engraving on 7075 Al Alloy Tribological Properties

Abstract

During various applications in aerospace, ships, autos, and aircraft, 7075 Al alloy will frequently contact other materials, and therefore suffer from slight abrasion. However, the poor tribological properties of 7075 Al alloy greatly affect its performance and life length, leading to limitations in its application. Preparing roughness structures on the surface is regarded as a promising method to improve the properties of materials. However, the tribological properties of 7075 Al alloy cannot be enhanced significantly by roughness structures in complex dynamic changeable environments, owing to the incomplete understanding of the effect of roughness structures. Given the above issues, in this paper, micro-scale structures (linear grooves, gridding grooves, and arc grooves) were designed and prepared on 7075 Al alloy surfaces by a surface treatment (laser micro-engraving), which provides excellent controllability of the morphology and dimensions of as-prepared roughness structures. The tribological properties of the as-prepared surfaces were investigated systemically. The effect of micro-scale structures on the tribological properties was studied. The wear mechanism and tribological properties improvement mechanism of the surfaces were clarified. Furthermore, the effect degree of the enhancement factors of the micro-scale structures on the tribological properties was explored under different conditions. The results indicate that the micro-scale structures play an important role in improving the tribological properties of Al alloy under different sliding speeds. The improvement mechanism can be summarized by four factors. However, the effect degrees of these factors on the tribological properties exhibit considerable differences. This study not only develops specific micro-scale structures that can dramatically improve the tribological properties of 7075 Al alloy under different conditions, but also offers guidance for the construction of appropriate roughness structures that can dramatically improve the tribological properties of Al alloy according to the friction conditions.

Influence of Laser Texturing and Coating on the Tribological Properties of the Tool Steels Properties

“…Methods that improve the integrity of the surface and at the same time reduce the coefficient of friction between the contacting surfaces can be included among the options that allow the reduction of the coefficient of friction and the reduction of the thermal load. This includes options such as surface hardening, chemical-heat treatment (carburizing, nitriding and boriding), laser welding, laser texturing and, finally, coating (PVD, CVD) and others [11][12][13][14][15][16][17][18].…”

The Effect of Ultrafine-Grained (UFG) Structure Formed by Equal-Channel Angular Pressing in AA7075 on Wear and Friction in Sliding against Steel and Ceramic Counterbodies

“…Laser surface texturing was also used to improve the wear resistance of AA7075 [17]. The treatment resulted in hardening the surface, which allowed for a reduction in the intensity of plastic deformation and adhesion.…”

Anti-Wear Property of Aluminum–Silicon Alloy Treated by Chemical Etching, Mechanical Honing and Laser Finishing

“…Traditional honing technology is widely used for the cast iron cylinder liner [18,19,20], it is by means of the oilstone embedded in the honing head to process the surface, but it may not be suitable for an Al–Si alloy cylinder liner because the aluminum may easily cover the silicon during the traditional honing process. Laser processing technology is also widely utilized in manufacturing to improve the properties of materials, such as laser cladding, laser surface alloying and laser remelting [21,22,23,24].…”