Advanced Materials Research Vol. 795

Abstract: The aim of the study is to identify the effect of Ca in Mg-Mn alloy on electrochemical corrosion behavior for the development of high performance sacrificial anode. Mg alloys were fabricated by casting technique under an inert atmosphere. 0.35 ~ 1.11 wt.% of Ca were added as alloying element. The finding shows that the addition of small Ca in Mg-Mn anodes was found not significantly affecting the corrosion rate. However, small content of Ca was as much as necessary improving electronegativity of open circuit potential and modifying anodic polarization in promoting the instabilities of surface passive layer hence results in the further dissolution process between ion and alloy species underneath. No passivation occurs on the standard samples. Pitting profile only occur on Mg-Mn anode that has lower Ca content (0.35 wt. %). An XRD result shows no present of Mg₂Ca phase on the as-cast anode containing 1.11 wt. % Ca. As a conclusion, the influence of small content of Ca was profoundly modifying electrochemically behaviour of Mg containing Mn anodes except corrosion rate.

Abstract: Al based alloy has been widely used in various industries. This research paper aims at the investigation onto the effect of the percentage of Cu and Ni alloying elements in the corrosion behavior of Al-Cu-Ni alloys. The alloys were characterized by microstructural, physical properties, electrochemical, and phase analysis. Microstructure observation shows the alloys have transformed to dendritic structure. The addition of Ni reveals columnar twinned dendritic to the longitudinal direction of cast ingots. While the addition of Cu increases the density of the sample. The Vickers micro-hardness test shows that sample Al86-Ni5-Cu3-Y6 reached the optimum hardness value 51.36 HV. Tafel Plot performed shows that Al86-Ni5-Cu3-Y6 has the highest Polarization Resistance, Rp, 2 031.82 kΩ and lowest corrosion rate, 0.00380 mm per year. Alloy with high Rp value is highly resistant to corrosion.

Abstract: The study presents the electroless N-P-C_g-SiC composite coating on cast AlSi (ADC12) alloy where the bath temperature is maintained at 90°C, pH level is controlled between 4.5 to 5.0 and stirred at 450 rpm with mechanical stirrer to avoid particles sedimentation. The increase of the coating film thickness is very insignificant after one hour of coating duration. This outcome is supposed to be due to inconsistent chemical concentration in the plating bath after this period. The nominal coating thickness of 39 μm is achieved after the substrate is immersed for 1 hour in four consecutive plating baths, respectively. The coating film is also successfully adhered to the substrate surface with the SiC and C_g particles are homogenously distributed.

Abstract: The study presents the effect of heat treatment on electroless N-P-C_g-SiC composite coated cast AlSi (ADC12) alloy. No significant changes are noted on the average surface roughness and surface morphology of the coating film with different heat treatment processes. The growth of the hard Ni₃P phase in the electroless Ni-P-C_g-SiC composite coating after heat treatment at 400°C for one hour strongly enhance the micro hardness of the AlSi-alloy (ADC12) surface from originally 101HV to 689HV. However, the micro hardness of the cast AlSi-alloy substrate decreases form 100HV to 60HV.

Abstract: The effect of cure characteristics and hardness of LCr filled SMR L compound were investigated. The size of LCr were 20 25 mm in range. Six compounds; 0, 5, 15, 25, 35 and 50 per hundred rubber (phr) of LCr were prepared by using two roll mill at room temperature. Cure characteristics such as scorch time,t₂, cure time,t₉₀, minimum torque, M_L, maximum torque, M_H, and cure rate index (CRI), and hardness of LCr filled SMR L were examined using rheometer. Result indicated that, all results for t₂, t₉₀, M_L and M_H shows the decrease with increasing in filler loading. CRI shows the increasing value with increasing LCr loading. Hardness, H_a value increase slightly with increasing LCr loading.

Abstract: One alternative to enhance the degradability of polyethylene is the addition of prooxidant substances to their matix. The polymer materials are called oxo-biodegradable. Current investigation aimed to assess the abiotic degradation of linear low densit polyethylene (LLDPE), formulated with soya powder and cobalt stearate as prooxidant additives. The blends of LLDPE/soya powder are to improve the degradability of the materials. The samples with different blends ratio and fixed amount of cobalt stearate was buried into natural soil. It was found that the tensile strength and elongation at break of the eroded materials from the pro-oxidant activated samples were significantly lower than the control sample without cobalt stearate. These samples underwent biodegradation and gave weight loss values up to 9% over 6 months of soil burial. The blends with higher soya powder content shows higher degradation in compost medium.

Abstract: In this work, we present results about the preparation and characterization of stannous oxide (SnO) thin films. SnO thin films were obtained via thermal evaporation method from SnO₂ powder as source material. These thin films were successfully deposited onto well cleaned glass substrates by thermal evaporation technique. The as deposited thin films were of thickness of 2500 Å and film were post-deposition annealed in air ambient at 400°C for 20 min and 40 min, respectively in a furnace. As-deposited films are highly conductive and p type. The best p-type SnO film annealed at 400 °C for 40 min shows a resistivity of 1.05 Ω·cm and a relatively high hole concentration of 2 × 10¹⁷ cm³ at room temperature. The X-ray diffraction (XRD) patterns of annealed films exhibit a polycrystalline hexagonal wurtzite structure without preferred orientation. The scanning electron microscopy (SEM) image shows the presence of uniformly dispersed spherical in shaped SnO particles. The mean grain sizes (diameter) are calculated to be about 80 and 100 nm for the p-type SnO films prepared at 400 °C for 20 min, and 40 min, respectively. Room temperature photoluminescence (PL) spectra of the SnO film exhibit two emission bands, around the wavelength of 300 nm and 450 nm. All spectra were measured at room temperature.

Abstract: Recently microfluidic has drawn attention from fellow research because of their unique properties and behavior in biotechnology, biomedical, micro and nanotechnology. Microfluidic is a combination from several components that consists from Microhannel, micromixer, microchamber, concentrator, separation and valve but component of microfluidic will be conduct in simulation is microfluidic separation and microchannel. This paper will elaborate more about design of microchannel separator by using COMSOL Multiphysics 3.5 software and base on the result from the COMSOL Multiphysics 3.5, we can create a detail design in the autoCAD software and lastly, as the result for this paper is an actual fabrication mask will be reveal for further fabrication process.

Abstract: This paper deals with the current transport mechanism of solid state photoelectrochemical cells of ITO/Cu₂O/PVCLiClO₄/graphite as well as the physical properties of a component of a device affecting its performance. The principle of operation used in the photoelectrochemical cells is presented. The device makes use of ITO films, Cu₂O films, PVCLiClO₄ and graphite films as photoanode, photovoltaic material, solid electrolyte and counter electrode, respectively. The device shows rectification. The J_sc and V_oc obtained at 100 mW cm² were 3.2 x 10^-11 mA/cm² and 0.92 V, respectively.

Abstract: F-75 (Co-Cr-Mo) alloy are widely used in the production of medical implants because of their excellent strength properties, hardness and also one of the biocompatible materials that very suitable in human body environment. In this research, the effect of sintering in terms of sintering temperature and sintering time has been studied by focusing on the microstructure, physical and mechanical properties of F-75 alloy. The samples were prepared by blending the starting material at 160 rpm for 30 minutes, uniaxially pressing at 500 MPa and sintering in an argon atmosphere at two sintering temperatures (1300°C and 1350°C) for four sintering times (60, 90, 120 and 150 minutes). The results show that the grains and bulk density increased with the increasing of sintering temperature and sintering times. However, opposite results were obtained for apparent porosity, hardness and compressive strength