Studying the Mechanical Properties of Cu- 20Fe- Gr Composites for Chain Brake Bits Applications Manufactured by Powder Technology

Cu-Fe is an important alloy that has a superior mechanical property suitable for many engineering applications. In this study Cu20 % Fe alloy is reinforced with 2,4 and 6 % graphite for manufacturing of a new material suitable for chain brake bits application. Cu-20Fe is prepared by mechanical alloying. Graphite powder is chemically coated with 5% nano Ag by electroless chemical deposition, then 10wt.% nano copper layer to improve it's wettability with both Cu and Fe. 2,4 and 6 % Gr are mixed with Cu-20 %Fe alloy by 6 :1 ball to powder ratio & 300 rpm for 6 hrs milling time. All mixed composite powders were compacted under 700 Mpa by a uniaxial press, then sintered in a vacuum furnace at 950◦C for 90 min. Density, XRD and microstructure for all sintered samples are examined. The hardness and wear resistance also estimated. The results indicated that 2% Gr sample has the highest density value and as the graphite percent increase the density decrease. XRD revealed only the main peaks of Cu, Fe and Gr and no any foreign phases were recorded 2% Gr sample has the most homogenous microstructure with no porosity. Hardness and wear also indicated that 2% Gr sample has the highest hardness value and low wear rate