Zr-based bulk metallic glass (BMG) has outstanding mechanical, physical and chemical characteristics compared to currently used biomaterials such as stainless steel, titanium and cobalt based alloys. However, BMG is characterized by low hardness and bio-inert native oxide surface. Therefore, it does not allow tissue growth and cell adhesion when implanted into the host body. This study, attempts to improve the surface quality of Zr-based BMG by suspending a bioactive hydroxyapatite powder in the dielectric fluid during the electro discharge machining (EDM) process. Field Emission Scanning Electron Microscopy (FESEM) and Mitutoyo roughness tester were used to study the surface morphology and the surface topography of the machined surface. The BMG surface hardness measured by Rockwell machine at 150 kgf load raised from 49.9 HRC to 85.5 HRC. The EDS spectrum revealed the formation of HA-rich layer deposited on the HA-EDMed BMG surface. A crack-free HA-EDMed surface, with some shallow craters and numerous nanopores was achieved. The surface roughness increased with increase in peak current and pulse duration and decreases when HA powder concentration increases. The lowest surface roughness of 1.976 µm were achieved at the current of 5 A and duration of 4 µs.

Several materials were considered for the Control Rod Drive Mechanism (CDRM) of Reaktor Daya Eksperimental, which is categorized as High Temperatures Gas-Cooled Reactors (HGTR). Nickel base alloys were found to be more superior compared to other types of materials for the CDRM. This paper reviews the mechanical properties and corrosion behaviour of Ni-base alloys at high temperature. The effect of neutron bombardment on the materials was also reviewed as an important condition. It is likely the that Inconel 625 and Inconel 686 are more suitable for the use of CDRM of HGTR, compared to another alloy, Incoloy 800H. The mechanical properties of Inconel 625 and Inconel 686 exposed at high temperatures are excellent, similar results found on the corrosion resistance. The neutron irradiation caused the embrittlement on Inconel 625 and Incoloy 800H. The yield and ultimate strength decreased insignificantly, ranging from 13-46%. Comparing with other mechanical properties, such as total elongation, it suffered much further reduction, ranging from 60-62%. This result implies that the materials underwent embrittlement.

Focused Ion Beam (FIB) has attracted extensive use in fundamental materials studies and technological applications over the last several years because it allows manipulation of the shape and size of nanostructures of a material. Focused Ion Beam and Transmission Electron Microscopy are responsible as sample preparation and nano defect failure analysis tool, respectively. This research was conducted to observe the failure of commercial blue LED that has been injected with high current. The optical dan electrical properties and structure characterization was carry out to identify the degradation of LED. It was observed that high current injection caused defect generation which affects electron transport in quantum well layer. Observation with TEM showed the existence of early defect in LED prior high current injection. The defects appeared in the form of discontinue and edge defect that was found in dark spot region of LED.

Linkage on the patient’s bed in the hospital when the dimensions are too large will cause a waste of materials. On the other hand, the strength of the linkage m Linkage on the patient’s bed in the hospital when the dimensions are too large will cause a waste of materials. On the other hand, the strength of the linkage m