Analisis Struktur Mikro dan Kekerasan Flens Motor Sungai Yangdibuat dengan Cor Cara Perah.

ANALISIS STRUKTUR MIKRO DAN KEKERASAN FLENS MOTOR SUNGAI YANGDIBUAT DENGAN COR CARA PERAH. Telah dibuat flens motor sungai dengan cor cara perah. Komposisi paduan adalah hipereutektik AlSi . Punch dari cetakan dibuat tirus, agar di bagian tengah flens mendapat tekanan yang lebih besar, karena bagian tersebut merupakan area yang paling berpotensi untuk aus, akibat gesekan dengan poros. Dari hasil pengamatan strukturmikro dengan mikroskop optik didapat morfologi bagian permukaan tengah mempunyai struktur yang paling halus, dibandingkan strukturmikro sisi luar di bagian tengah dari flens, karena bagian tersebut sudah membeku sebelum efek tekanan bekerja. Demikian juga hasil uji kekerasan, di bagian tengah mempunyai kekerasan yang paling besar yaitu 94 VHN, sedangkan di sisi luar bagian tengah flens hanya 81 VHN. Sedangkan kekerasan flens hasil cor dengan cetakan pasir adalah 51,23 VHN

Characterization of Lithium Thin Film Battery Components Prepared by Direct Current Sputtering

New electrolyte materials allow the design of flat lithium primary or secondary batteries for miniaturised devices from smart cards to CMOS back up. In this paper, the preparation of LiPON thin film component and an all solid-state thin film batteries consisting of an LiPON solid electrolyte, layered rocksalt LiCoO2 electrode, Pt and ITO current collectors, and amorphous SnO anode manufactured using sputtering and vacuum evaporation techniques is presented and discussed. The crystal structure of the LIPON thin film deposited on different substrates such as glass, Si wafer and Pt surface was characterized by X-Ray Diffractometer (XRD) method. The as-deposited cathode films are amorphous or partially crystallized. The amorphous intensity pattern appear with diffuse peaks situated at angular positions of 2θ ∼14º, 22º and 48º. The thin-film battery was characterized by complex impedance and Scanning Electron Microscope (SEM) method. Cracks, which are dependent upon deposition times, are observed for the as-deposited cathode films. The impedance and conductivity characteristics of the sample, do not reflect the standard characteristics of a battery. This type of behaviour could possibly be caused by the existence of a short circuit in the system configuration, so that the sample fails to generate the battery characteristics. In conclusion it could be safely assumed that the final result so far is just a multi-component system with a resistance value of 6 ohm, frequency-dependent capacitance, and a quasi Direct Current conductivity of 1.6 x 10-1 (S)

High-temperature Oxidation Behaviour Of Fe11al Based Alloys

HIGH-TEMPERATURE OXIDATION BEHAVIOUR OF Fe11Al BASED ALLOYS. Thermomechanically treated Fe11Al based alloys were isothermally oxidised in air at 900, 1000 and 1100 °C respectively. Their oxidation behaviour was studied using thermogravimetric analyser (TGA), X-ray diffractometer (XRD), and scanning electron microscope (SEM). It was found that the oxide scales formed on alloys studied consisted mainly of α- and θ-Al2O3. Additions of 0.5 wt. % Nb and Mo significantly improved the oxidation resistance of the alloys

Improved Corrosion Resistance of Ss316l Implant Materials by Nitriding Method

Nitriding has been carried out on SS316L implant materials by varying nitridation temperature of 400 °C, 420 °C, 440 °C, 460 °C, 480 °C and 500 °C for 3 hours,then followed by varying the nitridation time of 1 hour, 3 hours, 5 hours, 7 hours, 9 hours and 11 hours at optimum temperature of 420 °C. Corrosion test were conducted using potensiodynamic method with 0.9% NaCl intravenous solution as corrosion media of pH 7.4 at 37°C. The phase were characterized by using XRD (X-ray Diffractometer), while microstructure and surface chemical composition were analysed using SEM-EDS (Scanning Electron Microscope – Energy Dispersive Spectrometer). Corrosion test showed the corrosion resistance improvement by 16 times from corrosion rate of 0.1358 mpy for non nitrided SS316L to 0.0082 mpy for nitrided SS316L at 420 °C for 3 hours sample. X-ray diffraction pattern of SS316L implant materials as recieved shows the austenite phase (ã), while the nitrided SS316L at 420 °C for 3 hours is ã' phase. There is 2è angle shifting although not significantly, whereas the S phase was not observed. The observation of surface microstructure and chemical composition of non nitrided SS316L sample after corossion test showed the existence of pitting corrosion with 0.42% mass of chlorine. Sample nitrided at temperature of 420 °C for 3 hours showed a flat topography with black spots and from its cross sections, a thick nitride layer of 4 ìm and nitrogen element up to 31.34% mass were observed