The effects of β-Si3N4 whiskers and Fe–Cr–C alloy on the tribological properties of bronze matrix composites

In order to improve the wear resistance, Fe–Cr–C alloy and β-Si3N4 whiskers were chosen as the hard phases in bronze-graphite to prepare self-lubricating composite. Friction behaviors were tested with counter material 45# steel to evaluate the tribological properties of composites. The results indicated that Fe–Cr–C alloy and β-Si3N4 whiskers played different roles in composites. β-Si3N4 whiskers can obviously decrease the wear rate by excellent wear resistance. While the Fe–Cr–C alloy had better wettability with matrix, which improved the interfacial bonding and provided a continuous wear resistance. Moreover, Fe–Cr–C alloy also played a role in maintaining the friction coefficient stability, and this effect was more significant in the conditions of high rotational speeds. The composite containing 12.5 vol.% β-Si3N4 whiskers and 2.5 vol.% Fe–Cr–C alloy in this research showed good friction performance.

A Study of Characteristics of Aluminum Bronze Coatings Applied to Steel Using Additive Technologies

The influence of laser power on the microstructural, strength, and tribological characteristics of aluminum bronze coatings applied to steel by laser cladding was studied. It was found that with an increase in laser power, the morphology of the coating surface becomes more uniform without extreme height differences. This study revealed that the coating microstructure corresponds to that of a composite material and consists of a bronze matrix and iron dendrites of different sizes (depending on the laser power). Such a microstructure affects the microhardness indices, which have a scatter of values over the coating thickness. There is a diffusion zone at the steel–bronze interface, which promotes adhesion of the matrix and coating materials. According to the results of tribological tests, the dry friction coefficient for the studied samples is in the range of 0.389–0.574.

Development of Bronze Metal Matrix Composite for Automobile and Marine Applications

Bronze, an industrially relevant material, is always at a constant need for improvement in its properties. It should possess superior hardness, wear resistance and high tensile properties. The microstructure of the composite was characterized by using an optical microscope. The mechanical and tribological tests were carried out on the developed composite samples as per ASTM standards. It was observed that the hardness of the developed bronze composite increases with an increase in the reinforcement addition. The tensile properties were found to improve with addition of reinforcement particles into bronze matrix but, there observed a decrease in the ductility of the composite as compared to the regular bronze alloy. The wear rate of the developed composite was found to be low as compared to that of the regular bronze alloy

Study The Properties of Sintered Al-Composites Matrix Reinforced With Nano-Al Oxide And/Or Carbon Nano Tubes

The present work is concerned with studying the synthesis and characterization of hybrid aluminum bronze matrix strengthened with nano-aluminum oxide particles (n-Al2O3), and carbon nano tubes (CNTs). The selected matrix composite was successfully incorporated with different weighted percentages of CNTs (i.e. 1.0 and 2.0 wt.%) and/or n-Al2O3 (i.e. 1.0 and 2.0 wt.%) by sintering process. From the microstructure analysis, n- Al2O3 particles was dispersed uniformly and holding over the surface of aluminum bronze. Furthermore, some agglomeration was found due to reinforced CNTs into aluminum bronze matrix. From hardness tests, it was found that incorporated n- Al2O3 and CNTs into matrix increased the hardness of composites to be equal 230 HV, which is around 2.3 times higher than that of an aluminum bronze matrix. Moreover, the wear loss of CNTs - Al2O3/aluminum bronze composites diminished because of the impact of homogeneous circulation of CNTs in aluminum bronze and low corrosion coef?cient of uncovered CNTs on the well-used surface. Notable from the results, the electrical resistivity of the hybrid composites are lower than the matrix. Hopefully, the findings are expected to provide profound knowledge and further reference towards the studied composites of the miniaturised electronic package