Manufacturing and forming of composite material( Graphite/ al matrix

In the present study. a proposed technique called ”ex-situ and in-situ powder metallurgy” has been developed to produce aluminum-graphite (AVGr) composites. One of the main objectives of this work is tomanufacture the reinforcing graphite nanoplatelets (CNPLs)] materials inthe laboratory from the normal graphite flaks. In order to avoid anyinterfacial reactions between the graphite and the aluminum, an coldpressing of material powders at room temperature followed by hotextrusion techniques was used.Five weight percentages of graphite flakes were mixed withcommercial AI powder using a mechanical mixing stirrer. The thermalcharacteristics and microstructures of the composite were investigated.The results showed that some graphite flakes have reacted with siliconpresent in commercial aluminum powder and formed silicon carbide(SiC) at temperatures above 252 -CO SiC has great effect on compositecharacteristics. The effects of graphite content and SiC formation onstructure characteristics and properties of composites were investigated.The results also showed refinement and uniform distribution of graphiteand SiC particles within the alurninurn matrix.The mechanical properties of the composites were recorded atroom temperature. Experimental results showed that CNPLs weredistributed homogeneously in the (CNPLs I AI) composites. The CNPLscontent affects significantly the mechanical properties of (CNPLs I AI)composites. Meanwhile. the 2.0 wt.% CNPLs IAI composite is found toexhibit the highest hardness. yield and ultimate tensile strengths. Also. itis noticed that the elongation percentages remain nearly constant.