Microstructural evolution in ultrafine grained Al-Graphite composite synthesized via combined use of ultrasonic treatment and friction stir processing

摘要: Abstract An attempt was made to develop ultrafine grained Al-Graphite composites through friction stir processing (FSP). composite initially prepared using casting technique and it subsequently subjected ultrasonic treatment prior solidification. The results showed that the during preparation reduced porosity, graphite particles' agglomeration size in composite. treated a single pass FSP at constant tool rotational speed of 1600 rpm with three different feed rates, 20 mm/min, 40 mm/min 60 mm/min. microstructure FSPed within zone exhibited fine recrystallized grain structure due combined effect severe plastic deformation frictional heat generation FSP. After FSP, from 150 μm 14 μm, 6 μm 0.5–1 μm for transverse speeds 60 mm/min, respectively. Distribution particles Al matrix significantly improved after process strong stirring action rotating tool. Most importantly, microstructural analysis suggested substantial reduction could be achieved aid process. samples superior hardness as compared unprocessed uniform dispersion ultra-fine structure. In nutshell, Graphite nano were produced