Brake linings used in automotive disks are usually composed of various components. The expected properties of a brake lining are the standard values of wear resistance, friction coefficient and the economical manufacturing. Brake lining extremely warms up during braking due to friction. The braking performance of braking lining can change or the braking lining undergoes mechanical deformation due to excessive temperature. In this study, the effect of granite powder in the brake friction material on various aspects of friction characteristics were investigated. Three friction material specimens were produced based on an experimental formulation, and they contained 2, 6 and 10 % granite powder, respectively, with fixed composition of the other ingredients. Tribological properties of the friction materials were obtained using a brake dynamometer. Results showed that the friction materials containing 2 and 6 % granite powder had improved friction stability and fade resistance.

Aluminum alloys have been extensively used as structural material due to its high strength and damage-tolerance. Alloy 6061, 2024 and 7075 are engineered to be lightweight and strong,and their ease of formability allows complex shapes and drawn parts,which can then be further enhanced with heat treating. In this study is aimed to improve the mechanical properties of aluminum alloys by heat treatment.AA2024 and AA7075 were selected and each alone at T3 and T6 temper conditions has been studied respectively.For the mechanical properties of AA2024 and AA7075 alloyshardness, fatigue behavior, tensile test and charpy impact test with standard V notched specimens at RTand-5 °C were analysed in the present study. Microstructural characterization has been done using standard metallography.

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Keywords: Boron Carbide; Silisium Carbide; Composite; Powder Metallurgy. Abstract : In this study, effect of boron carbide (B4C), aluminium oxide (Al2O3) and silisium carbide (SiC) addition on microstructure and mechanical properties of diamond cutting segments was investigated. The effects of reinforcement particle additions on characteristic of CuSn matrix composites have been investigated. For this purpose, Al2O3, SiC and B4C addition quantity was added as 2 wt.%. Samples of segments were processed by cold pressing at 550 MPa, followed by sintering at 850°C/30min. Micro-structural aspects were observed by optical microscope. Density, hardness and wear tests were also performed. Wear behaviour and hardness values of segments changed depending on aluminium oxide, silisium carbide and boron carbide addition. The alloy CuSn– 2 wt.%. B4C presented the best results, available for use in cutting tools.