Development of Carbon Short Fiber Reinforced Al Based Composite without Preform Manufacturing

Abstract

The traditional manufacturing of short fiber reinforced composites by liquid processes require preform manufacturing using inorganic binders. However, conventional preform manufacturing techniques using inorganic binder are nontrivial procedures requiring high-energy inputs for binder sintering process. A novel alternative fabrication process without preform manufacturing was developed for carbon short fiber (CSF) reinforced Al based composite by low-pressure infiltration method. The volume fraction of CSFs in the composites was 10 vol%. Two kinds of CSF/A1070 composites were compared in this paper, one is manufactured with preform manufacturing technique (with SiO 2 binder) and the other is fabricated without preform manufacturing. The microstructures of both the specimens were observed for defects in the composite. In the CSF/A1070 composite obtained from the new manufacturing process, defects by aggregation of CFSs were reduced. Furthermore, compared with the CSF/A1070 composite by preform manufacturing with SiO 2 binder, the relative density of the CSF/A1070 composite obtained from the new manufacturing process is also observed to increase from 96.6% to 97.8%. CSFs were randomly dispersed inside the composites obtained through the new manufacturing process. The Vickers hardness of the CSF/A1070 composite obtained through preform manufacturing and the new manufacturing process was 33.5 Hv and 41.3 Hv, respectively. Furthermore, CSF/Al based composites using the A356 and A336 alloy as matrix were also manufactured through the new fabrication method. The Vickers hardness, relative density of CSF/A356 and CSF/A336 alloy