MICROSTRUCTURAL MODIFICATION OF CAST ALUMINIUM ALLOY AlSi9Mg VIA FRICTION MODIFIED PROCESSING

摘要

Friction Modified Processing (FMP) is a new solid state processing technique which can be used for microstructural modification in metallic materials. The FMP process has been applied to cast aluminium alloy AlSi9Mg plates to modify the microstructure. The FMP process refinement and dispersed the coarse acicular Si particles creating a uniform distribution of Si particles in the aluminium matrix. Furthermore, the porosity of as cast AlSi9Mg alloy was nearly eliminated by FMP. The current study also aims to develop a model describing the quantitative relationships between volume and mass of modified material and processing speeds over a wide experimental range. An exponential formula has been found to describe the relationship between penetration depth, volume and mass of modified material and rotational speed. The evaluation on travelling speed affecting penetration depth, volume and mass of modified material can be approximately made through linearly functions.