The Influence of Selected Laser Engraving Parameters on Surface Conditions of Hybrid Metal Matrix Composites.

Hybrid metal matrix composites (HMMCs) are a special type of material, possessing combined properties that belong to alloys and metals according to market demands. Therefore, they are used in different areas of industry and the properties of this type of material are useful in engineering applications, e.g., in aircraft engines and electrotechnical parts. The structure of the material requires a number of scientific studies to develop an appropriate processing technology. The paper presents the susceptibility of material from the HMMCs group with the EN AC-44300 (AISi12(Fe)) aluminum alloy matrix with a two-component reinforcement made of alumina particles (AP) and aluminosilicate fibers (AF) to thermal treatment with a laser beam. During this process, laser engraving of the researched material with variable beam power and variable speed of the laser head were carried out. A metallographic analysis of the material was carried out. After laser engraving, surface structural changes of the material were determined. The properties of the surface geometric structure of processed material were also examined. Presented studies concern laser engraving on the surface of composite from the HMMC group, which was made by vacuum infiltration. Thanks to this method, it is possible both to produce shaped and precise composite castings with saturated reinforcement and to consequently minimize machining losses. Metal-ceramic composites from the HMMC group are hard-to-machine materials which create problems during machining. The aim of these studies was to develop a laser engraving technology with Al matrix composite with the addition of AlO particles and aluminosilicate fibers, which constitute the reinforcement. The focus was on the selection of engraving parameters (beam power and speed of movement of the laser head). Clear examples of engraving, suitable for macro-assessment, were obtained with minimal change in the initial surface structure of the composite.