Volume Volume 5 No.2 1995

ABSTRACT: A technique was developed for measuring the transient temperatures that develop at points within the thickness of welded plates during the welding process. Type K thermocouples were used; the technique allows them to be reused. They were used to measure the transient temperatures that developed due to welding at the mid-thickness of three 15 mm thick steel plates. The measured temperatures agreed with the temperatures predicted by a 3 Dimensional Non-Linear Finite Element computer program that had recently been developed. The symmetry of the temperature distributions in (nominally) centrally welded plates can be significantly affected by relatively small eccentricities of the weld line. It was also shown that the maximum temperatures that were reached at the points within the plate could be affected by their proximity to the plate edges. AUTHOR: S.B. Bani, A.G. Kamtekar and G.H. Little

ABSTRACT: FTIR quantitative analytical method is described as an alternative technique for computation of the filler content in the composites. White rice husk ash (WRHA) was incorporated as a filler material into polypropylene homopolymer. Polypropylene/WRHA composites of different filler loadings were compounded using a Brabender twin screw extruder and test specimens were injection molded. The filler content determined through this technique is only a relative figure and not absolute as in the case determined by the thermogravimetric analysis since proper standard samples to calibrate the regression curves are not available. AUTHOR: M.Y. Ahmad Fuad, B.M. Arif, M.S. Mansor, Z.A. Mohd Ishak and A.K. Mohd Omar

ABSTRACT: Tiles with or without soaking in clean water were laid on cement mortars of different cement-sand ratio by using semi-dry method. When hardened, mortars with high cement content are denser than mortars with low cement content. The impact hardness of the mortar. with high cement content is thus higher. For a same cement content with excess water and non-suction system, soaked or non-soaked tiles show no obvious difference in density and hardness to the hardened mortars. However, for non-suction system, in non-soaked case, hardened mortar develops cracks of about 3 mm at the neat cement layer near to tile back area when water is just sufficient for the cement hydration process. This feature was not observed in the case where the tiles were soaked before laying under the same conditions. AUTHOR: S.S. Kang, S. Samsiah, M. Mazlan and S.M. Loo

ABSTRACT: Copper powder, for powder metallurgy applications, can be produced by electrochemical deposition method. This research work investigates the effect of powder deposition rate, current and process efficiency and powder structures through the addition of chemical additives into the mother liquor. High purity copper and lead were used as the process anode and cathode respectively while the concentration of copper ions and sulphate radicals were kept constant through out the experiment. The addition of glycerine and copper chloride as process additives were found to increase the deposition rate and the overall process efficiency. The generated copper particles were observed to have dendritic structure. Further processing produced flake and nodular particle morphology which were thought to be suitable for most powder metallurgy applications. Particle size analysis was done and an observation was made that the distribution lies within the commercially available sizes. AUTHOR: Mohd Amin bin Hashim and Fauzi bin Ismail