In this study, Cu-TiC composites were successfully produced using hot pressing method. Cu-TiC powder mixtures were hot-pressed for 4 min at 600, 700 and 800?C under an applied pressure of 50 MPa. Phase composition and microstructure of the composites hot pressed at different temperatures were characterized by X-ray diffraction, scanning electron microscope, and optic microscope techniques. Microstructure studies revealed that TiC particles were distributed uniformly in the Cu matrix. With the increasing sintering temperature, hardness of composites changed between 64.5 HV0.1 and 85.2 HV0.1. The highest electrical conductivity for Cu-10 wt.% TiC composites was obtained for the sintering temperature of 800?C, with approximately 68.1% IACS.

No abstract

In this paper, wear properties of NiCrBSi-SiC coatings were investigated using the ball-on-disk wear test. In experimental study, NiCrBSi-SiC powders were sprayed using a high-velocity oxygen fuel technique on an SAE 1030 steel substrate. Powder mixtures with different weight mixing ratios, NiCrBSi + 10 wt% SiC, NiCrBSi + 20 wt% SiC and NiCrBSi + 40 wt% SiC coatings were prepared. The deposited coatings are compared in terms of their phase composition, microstructure and hardness. It is proved that the degree of mixing of the NiCrBSi and SiC components in the powder has a massive effect on the phase composition, microstructure and hardness of the coatings. Wear tests were conducted on both the uncoated and coated substrates at same normal load, speed, and wear distance. It has been determined that the coated substrates exhibit a very good tribological performance in comparison to the uncoated substrate. The increase in the adhesive wear resistance provided by the

In this study, AlCu matrix hybride composites with various ratios of boron carbide (B4C), hexagonal boron nitride (hBN), and graphite (Gr) were produced by using hotpressing method. The microstructure, density, mechanical and corrosion properties of these composites were investigated. Optical microscopy, scanning electron microscopy, and X-ray diffraction were used to characterize the microstructures, and the experimental densities of the composites were measured using a helium pycnometer. The mechanical properties including the hardness and transverse rupture strength were investigated using hardness and three-point bending tests, respectively. In addition, the hybrid composites were immersed in an aqueous solution of 3.5 wt.-percent NaCl at pH 3 for potentiodynamic and corrosion rate measurements. These tests revealed that a microstructure in which reinforcing particles are almost homogeneously dispersed in the matrix was obtained. Density measurements have shown that very dense and compact hybrid AMCs are produced. The hardness and transverse rupture strength of the composites were significantly increased by particulate addition to the matrix. Depending on the type and amount of reinforcement material, differences in the corrosion resistance of the hybrid composites have been determined. The results show that AlCu-8B 4 C-2Gr hybrid composite material has the highest corrosion resistance among the composite materials.

The aim of this work was to investigate the effect of cBN content and sintering temperature on the transverse rupture strength (TRS) of cBN/diamond cutting tools produced by hot pressing. The segments containing different cBN content were manufactured under 35 MPa pressure at 600, 650 and 700°C with a 3 minutes sintering time. The TRS of segments were determined using three-point bending test. Microstructure and phase composition of fracture surface of segments were determined by scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The obtained results show that the TRS of the segments with cBN were higher than that of the segments with diamond