Effects of SiC Particle Size on Properties of Cu-SiC Metal Matrix Composites

This paper was focused on the effects of particle size and distribution on some properties of the SiC particle reinforced Cu composites. Copper powder produced by cementation method was reinforced with SiC particles having 1 and 30 μm particle size and sintered at 700°C. Scanning electron microscopy studies showed that SiC particles were dispersed in copper matrix homogeneously. The presence of Cu and SiC components in composites were verified by X-ray diffraction analysis technique. The relative densities of Cu-SiC composites determined by Archimedes' principle are ranged from 96.2% to 90.9% for SiC with 1 μm particle size, 97.0% to 95.0% for SiC with 30 μm particle size. Measured hardness of sintered compacts varied from 130 to 155 HVN for SiC having 1 μm particle size, 188 to 229 HVN for SiC having 30 μm particle size. Maximum electrical conductivity of test materials was obtained as 80.0% IACS (international annealed copper standard) for SiC with 1 μm particle size and 83.0% IACS for SiC with 30 μm particle size

An Evaluation of Cu-B₄C Composites Manufactured by Powder Metallurgy

In this study, the influences of B₄C ratios on some mechanical and physical properties such as relative density, microhardness and electrical properties of cold pressed Cu-B₄C composites were investigated. Curve fitting is applied for the estimation of electrical conductivity. Commercial copper powders with 40 μm particle size were reinforced with B₄C, with particle size of 40 μm, at ratios of 1, 2, 3 wt.%, for improving mechanical properties of copper used as electrical conductor. Cu-B₄C composites have been fabricated by powder sintering process at a temperature of 900°C for 2 h. The presence of Cu and B₄C, which are dominant components in the sintered composites, were confirmed by X-ray diffraction analysis technique and SEM-EDS. Scanning electron microscope (SEM-EDS) has shown that B₄C particles are distributed homogenously in the copper matrix. The relative densities of Cu and Cu-B₄C composites, sintered at 900°C, ranged from 95.7 to 91.6%. Microhardness of composites ranged from 84.5 to 94.6 HB. It was observed that cold pressed Cu-1 wt.% B₄C composites revealed promising physical properties. Results of electrical conductivity measurement of Cu-B₄C composite material are compared to the results of the model and the overall accuracy level above 96% is obtained

Comparing of Commercial and Cemented Cu-SiC Composites

SiC with 30 μm particle size reinforced copper composites have been fabricated by powder metallurgy method and sintered at 700C for 2 h in open atmosphere. Copper powder was produced by cementation method and obtained as commercial for comparing. Cemented and commercial copper powders were reinforced with SiC having 30 μm particle size at ratios of 0, 1, 2, 3, and 5 wt% for improving mechanical properties of copper without decreasing the electrical conductivity. The presence of Cu and SiC which are dominant components in the sintered composites were confirmed by X-ray diffraction analyses technique. Scanning electron microscope showed that SiC particles are distributed homogeneously in the copper matrix. The relative densities of Cu and Cu-SiC composites sintered at 700C are ranged from 98.0% to 96.2% for commercial Cu-SiC composites, 97.55 to 95.0% for cemented Cu-SiC composites, microhardness of composites ranged from 133 to 277 HV for commercial Cu-SiC composites and 127 to 229 HV for cemented Cu-SiC composites, and the electrical conductivity of composites changed between 95.6%IACS and 77.2%IACS for commercial Cu-SiC composites, 91.7%IACS and 69%IACS for cemented Cu-SiC composites. It was observed that there is a good agreement between cemented Cu-SiC and commercial Cu-SiC composites

AIP Conference Proceedings

In this study, we investigated some properties of bonded AISI 1020 steel. Boronizing heat treatment was carried out at 800 degrees C, 875 degrees C and 950 degrees C for 2, 4, 6 and 8 h using Ekabor 1 powders. The hardness of borides formed on the steel substrate measured via Vickers indenter was about 1500 HVN. The thickness of boride layers depending on the process temperature and time was ranged from 20.5 to 216 pm. The presence of Fe2B boride was determined by XRD analysis. SEM microscope studies showed that the borides formed on the AISI 1020 steel have columnar nature. Kinetics studies reveal a parabolic relationship between layer depth and process time, and the activation energy is calculated as 164,356 kJ/mol. Moreover, an attempt was made to investigate the possibility of predicting the iso-thickness of boride layer and to establish an empirical relationship between process parameters of bonding and boride layer for industrial applications