Effect of uncoated and coated diamond on the compressive properties of porous aluminium composites

Porous aluminium composites are structural and functional materials that have vast potential, due to their lightweight and high energy absorption capacity, especially in automotive and aerospace applications. In this study, the effect of varying content of uncoated and Titanium coated diamond particles on the compressive properties of porous aluminium composite was investigated. The composites were developed using powder metallurgy technique and porosity was attained by using polymethylmethacrylate (30 wt.%) as space holder material. The morphology of the pores was found to replicate the shape and size of polymethylmethacrylate particles, that were uniformly distributed in the composites. X-ray diffraction analysis confirmed formation of Aluminium carbide in uncoated diamond-based aluminium composites while negligible amount was present in titanium coated porous composites during sintering. The porosities of composites decreased with an increase in diamond content due to the incomplete decomposition of polymethylmethacrylate particles. Moreover, the maximum plateau stress and energy absorption capacity of 9.96 MPa and 1.7 Mj/m3 were obtained for the composites with 8 wt.% of titanium coated diamond particles. Thus, coating inhibits the formation of undesirable compounds and contributes to better interfacial bonding between matrix and reinforcement

Investigation of morphology and compressive properties of diamond reinforced porous aluminium composites

In the present work, porous aluminium composite with varying diamond particles content (4, 8, 12, and 16 wt. %) were developed via powder metallurgy technique. Porosity was attained by using 30 wt. % Polymethylmethacrylate particles as a space holder. The effects of varying content of diamond on the morphology, densities, porosities, compressive properties as well as energy absorption were studied. Morphology of the porous Al composite demonstrated the formation of closed- cell macro pores that were uniformly distributed within the Al matrix regardless of different content of diamond particles. However, increasing diamond content was found to alleviate un-wetting phenomenon between Al matrix and diamond particles leading to increased porosities from 34.8% to 26.2%. The compressive properties also declined however maximum values for plateau stress (7.50MPa) and energy absorption capacity 1.7(Mj/m3) were acquired at 8wt.% diamond content