16. Manufacturing of Copper Based Composites Reinforced with Ceramics and Hard Intermetallics for Applications of Electric Motor Repair Parts

In the present work, a recycled copper based composites reinforced with ceramic as an alternative replacement for the application of electric motor repair parts with the use of novel processing techniques.

A practical solution was proposed as cost effective economic manufacturing of the composites for this type of applications. Copper based composite design (Cu-Al-Nb₂Al) was based on the ceramic reinforcements such as titanium carbide (TiC) in different percentages and niobium aluminate intermetallics (Nb₂Al). Because TiC and Nb₂Al make a good combination of thermal and electrical conductivities, microstructural stability and strength retention at elevated temperatures, etc. These reinforcements increase considerably wear resistance of the composites for electrical contact applications. Otherwise, certain percentage of fresh scrap aluminium powder, the mixture of AA1050 (80 wt% + AA7075 (20 wt %) chips were used to create an exothermic combustion reaction in the process for helping diffusion bonding process of the ceramics to the copper matrix. At the first stage of the present work a preliminary study has been carried out for developing a cost effect and high wear resistant electrical brushes for aeronautical applications. Microstructural and wear analyses have been carried out to optimize the process conditions for a practical tool that will be used for final industrial applications. Three basic compositions were prepared depending on the percentage of TiC. The microstructure and damage analyses have been carried out by Scanning Electron Microscope (SEM).