Calcium phosphate based biomaterials have received great interest since the main constituent of inorganic mineral component in human bone is hydroxyapatite (HAP). This study aims to extract the natural HAP from bovine femur bone at different calcination temperature with different particle size. The experiment starts with cleaning process of fresh bovine femur bones. Then bovine bones were ground into different particle size (x ≤ 45μm, 45 < x ≤ 63μm, and 63 < x ≤ 125μm). All bone samples were furnace heated at temperatures of 700°C, 900°C, and 1100°C for three hours. Obtained apatite was characterized using field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The results indicate that increasing calcination temperature leads to organic free and higher crystallite size of HAP. In terms of particle size, crystallite size is increasing as particle size increases but the increment crystallite size is not significant. The report here proposed that calcination temperature above 700˚C may utilize in bone tissue engineering application

Use of cutting fluids in machining processes can reduce the cutting temperature and provides lubrication to tool and workpiece. These translate to longer tool life and improved surface quality. Due to the issues of using fluids in machining related to environment, health, and manufacturing cost that need to be solved, options to reduce their use. A technique called minimal quantity lubrication (MQL), which sprays small amount of cutting fluid (in the range of approximately 10 – 100ml/h) to the cutting zone area with the aid of compressed air, was developed to merge the advantages of both dry cutting and flood cooling. For the type of cutting fluids, vegetable oils are common cutting fluids used in MQL because of its superior lubrication and high-pressure performance. This study evaluates the performance of MQL using castor oil as cutting fluid. The workpiece is hardened stainless steel 48 HRC. Results are compared with dry cutting. It was found that using small amount of lubricant of 50ml/h during the particular turning process produces better results compared to dry cutting, in terms of longer tool life. Surface roughness and cutting forces were also enhanced albeit slightly. From the results, MQL can be a good technique for turning hardened stainless steel using coated carbide cutting tools for cutting parameters of up to 170 m/min cutting speed and 0.24mm/rev feed

Zn-based alloys have been studied as new biodegradable metals owing to its slower corrosion rate compared to Mg-based alloys and its high potential for mechanical properties improvement. The present work attempts to improve mainly the mechanical properties of a eutectic Zn-3Mg alloy via equal channels angular pressing (ECAP). Cast Zn-3Mg alloy was homogenized at 370 °C for 15 h and quenched in water before subjected to 2 steps ECAP process. Results showed that the process decreases the alloy’s grain size from 48 µm in the as cast to 1.8 µm after 2-passes of ECAP. A remarkably increase of yield strength, tensile strength and elongation was achieved from 65 MPa, 84 MPa and 1.3% (as cast) to 205 MPa, 220 MPa and 6.3% (2-ECAP), respectively. Corrosion rate of the alloy was fairly altered from 0.30 mm/year (as cast) to 0.24 mm/year (2-ECAP). The combination of homogenization and ECAP is therefore viewed as a potential process to improve mechanical properties of Zn-Mg alloys