Effect of high temperature chemical etching on surface roughness of tungsten carbide substrate

High hardness, lower thermal expansion and friction coefficient, chemical inertness and strength are the most important characteristics of cutting tools, which can be enhanced by coating the tool surface with a thin layer of diamond. A variety of surface pretreatment methods have been developed to enhance diamond nucleation rate density and adhesion strength between diamond films and substrates which include scratching, seeding, electrical biasing, pulsed laser irradiation, interlayer, ion implantation, carburization and chemical pretreatment. Among them, chemical pretreatment is the simplest and cheapest. In this paper, a single step chemical pretreatment using mixture of sulfuric acid and hydrogen peroxide solutions were carried out on tungsten carbide with 6% cobalt (WC-6% Co). Three independent variables such as concentration of sulfuric acid, etching temperature and time were varied to investigate the best combination of these parameters for roughening the WC-6% Co surface. It was found that the highest surface roughness (Ra=1.3μm) was obtained when using 95% concentration of sulfuric acid, and lower etching temperature of 40oC in duration of two minutes etching time

Corrosion Behavior of Antimony (Sb) Modified Galfan (Zn-Al) Coated Steel

High corrosion resistance of Zn-Al-Mg (ZAM) alloy is widely used in steel wire rope protection. This alloy, however, due to Mg reactivity, easily induced dross formation containing MgZn2 and Mg2Zn11 which reduced the coating integrity. Thus, in this work, Mg is replaced with various wt.% Sb (ZAS) coated on steel surface will via hot-dip process at the eutectic environment. The thickness of the intermetallic layer and coating thickness were observed using an optical microscope and SEM. It was found that 0.3 wt.% Sb improved the corrosion performance 45.5% (0.00267 mmpy) than ZAM coated steel (0.00490 mmpy) under accelerated corrosive medium of 3.5% NaCl.</jats:p

Corrosion behavior of antimony (SB) modified galfan (ZN-AL) coated steel

High corrosion resistance of Zn-Al-Mg (ZAM) alloy is widely used in steel wire rope protection. This alloy, however, due to Mg reactivity, easily induced dross formation containing MgZn2 and Mg2Zn11 which reduced the coating integrity. Thus, in this work, Mg is replaced with various wt.% Sb (ZAS) coated on steel surface will via hot-dip process at the eutectic environment. The thickness of the intermetallic layer and coating thickness were observed using an optical microscope and SEM. It was found that 0.3 wt.% Sb improved the corrosion performance 45.5% (0.00267 mmpy) than ZAM coated steel (0.00490 mmpy) under accelerated corrosive medium of 3.5% NaCl

Solar and biomass potential of renewable energy in selected ASEAN countries and Japan

AbstractASEAN region is believed to have a great potential for biomass and solar energy generation due to its abundance of sunlight, rain, and fertile land. However, these resources are still underutilized as the current rate of renewable energy is relatively low, whereby most countries are still highly emphasizing fossil fuels. The use of fuel without replenishing the fuel source will ultimately deplete the resource in very much the same as fossil fuels currently utilized. While the concept of fuel replenishment seemed simple, the implementation posed a challenge to meet. This is where free energy in the form of solar, wind, wave, underground thermal, and biomass is being harnessed. Therefore, these forms of energy also have certain limitations depending on the geographical and the availability of the sources throughout the region. This study aims to analyze the current potential renewable energy scenario and future prospect of renewable energy resource for biomass and solar energy in selected ASEAN countries and Japan.</jats:p

Solar and biomass potential of renewable energy in selected ASEAN countries and Japan

ASEAN region is believed to have a great potential for biomass and solar energy generation due to its abundance of sunlight, rain, and fertile land. However, these resources are still underutilized as the current rate of renewable energy is relatively low, whereby most countries are still highly emphasizing fossil fuels. The use of fuel without replenishing the fuel source will ultimately deplete the resource in very much the same as fossil fuels currently utilized. While the concept of fuel replenishment seemed simple, the implementation posed a challenge to meet. This is where free energy in the form of solar, wind, wave, underground thermal, and biomass is being harnessed. Therefore, these forms of energy also have certain limitations depending on the geographical and the availability of the sources throughout the region. This study aims to analyze the current potential renewable energy scenario and future prospect of renewable energy resource for biomass and solar energy in selected ASEAN countries and Japan