Advanced Materials Research Vols. 383-390

Abstract: In this investigation an attempt has been made to highlight the influence of axial force on the mechanical and metallurgical properties of friction stir welded aluminum alloy AA6082-T651 joints. The axial force is varied from 3 kN to 8 kN on the surface of the base material. Tensile test, macrostructure and microstructure tests were performed on all the welded specimens. SEM was used to know the behavior of the fractured surface of the tensile test specimens. It is found that the joint fabricated at 6 kN axial force has higher tensile strength and good metallurgical properties.

Abstract: The high-speed ceramic electric spindle is applied in high-speed NC machine tools. Now the technology of ceramic spindle with its excellent performance applied to electric spindle is becoming a kind of important development trend. Each surface processing accuracy requirement of high-speed ceramic electric spindle is high. The performance of the electric spindle in largely determines machining precision and production efficiency of the high-speed machine tool. In order to meet the requirements of high speed, high accuracy, high reliability and small vibration in the rapid processing of machine tool, it is necessary to make a rigorous precision testing for the precision-processed spindle and obtain reliable data to meet the design standards and performance requirements of all ceramic high-speed spindle. This paper focuses on the research of surface roughness, roundness and cylindricity analysis of spindle external circular, which can make the precision-processed zirconia ceramic spindle pore to meet the design requirements and provide reliability safeguard to promote the using life and high-speed dynamic balance stability of the whole electric spindle.

Abstract: Red mud is the main solid residue generated during the production of alumina by means of the Bayer process. In order to expand the comprehensive utilization field of red mud and develop new ceramic products with low radioactivity utilizing red mud, the exploration of preparing self-releasing glaze ceramic materials using red mud as raw material was carried out. During the exploration, the self-releasing glaze ceramic materials with low radiation level were produced by normal pressure sintering process using the main ingredients of red mud, red sandstone, barium carbonate and ball clay. The properties of the self-releasing glaze ceramic samples were investigated by the measurements of mechanical properties, X-ray diffraction (XRD), scanning electron microscopy (SEM) and radiation measurement. The results show that the self-releasing glaze ceramic materials have good mechanical properties (the bulk density, 3.10 g/cm3; the compressive strength, 78.00 MPa). Adding barium carbonate to the raw materials and then calcine them to ceramics, which can extend the sintering temperature range and the radioactivity level of the self-releasing glaze ceramic materials can be reduced to that of the natural radioactive background of Guilin Area, Karst landform (the average 60 Total/Timer).

Abstract: Sustainability is becoming an important tool towards our better future. More and more companies are looking into sustainability as their prime focus. Sustainability encompasses responsibilities towards social, energy, water, pollution and economic factors. Sustainability is the ability to sustain. Sustainability Index evaluation criteria and checklist has been created for a typical semiconductor manufacturing industries and the sustainability index has been compared with similar industry. Based on the benchmarking conducted for two plants one of them ranked at 75% indicating high on sustainability index. Benchmarking on sustainability index is a useful measure for shareholders, customers and employees.

Abstract: Experiments using pineapple leaf fiber as raw material in paper production have been conducted to assess the advantages in terms of mechanical properties, especially tensile strength, tearing strength and thickness of the paper. In this paper, samples of pineapple leaf fiber is mixed with a recycle newspapers in different composition of which is, 25%, 35%, 45%, 55%, 65% and 75% pineapple leaf fibers mixed with 75%, 65%, 55% , 45%, 35% and 25% of the recycle newspapers. The mixtures have been tested for mechanical properties and thickness by using the Universal Testing Machine (UTM) and micrometers. The results from tensile and tearing tests were then compared with data obtained from previous experiments. Through the observation of the experiment, it was found that the data obtained with similar experiments conducted previously. The results have been proved in tears testing and stress testing. Tearing test data shows that the longer the beating time imposed on the mixture, the lower the tearing force required to tear the paper samples. On the other hand, the tensile test results shows, the longer time beating the bear on the mix, the higher the tensile force should be imposed on the sample. The experimental results can help in the formulation of the pineapple leaf fiber-based paper production in accordance to the usage.

Abstract: This paper discusses the significant percentage increase of environmental impact generated in the manufacturing phase as a result of changes in the key material selection during the product design process. The findings in this paper are important for product designers. They need to pay extra attention when choosing plastics or metals when assessing design alternatives that can reduce the environmental impact. Four products were analysed in this case study namely water pump, hot pot, plastic kettle and stainless steel kettle. The environmental impacts of these four products are assessed by Life Cycle Assessment (LCA) and the CML approach from Institute of Environmental Sciences is adopted as the Life Cycle Impact Assessment method.

Abstract: As manufactured vehicles have become more global, the competitive pressures from multi-national companies have increased substantially. Based on that, it is clearly shows that, the important of understanding the implementation of green indicators concept. Hence, the principal aim of this paper is to highlight the establishment of Green Design concept for Malaysia automotive industry by establishing a set of ‘Critical Success Factors’ that will be applied at the design stage. Survey methodology was employed to collect data. Data were obtained from 104 automotives companies and related suppliers in Malaysia with 29% response rate. This paper presents findings of Confirmatory Factor Analysis (CFA) results on green design concept for Malaysia automotive industry.

Abstract: Sustainability manufacturing is indispensable to change and adapt from existing processes which enrich huge expertise. However, it needs to have prior assessment. Thai SME bus building companies are mostly established for more than 30 years of experiences. However, they still lack of competitiveness. The manufacturing process is time consuming, high costs and used extra material. This paper proposes the sustainability manufacturing assessment according to the D4S method associated by PCA tool. Five major companies in Thailand are surveyed and mapped to diagnose for sustainability level.

Abstract: Cement is an essential constituent for the production of concrete. Nowadays, the supplementary use of cement such as industrial by-product and agricultural waste material has become an integral part of concrete construction due to their cost effective and sustainable environmental benefits. The industrial (metallurgical) by product-Granulated Blast Furnace Slag (GBFS) contains a non-crystalline silicon dioxide with high specific surface area and high pozzolanic reactivity. The use of GBFS either in cement or concrete has been increased due to its better performance in concrete in terms of strength and durability. In this paper, a critical review on the influence of slag and slag cement on the strength of sustainable concrete has been presented. The researches carried out in the past on the use of GBFS as partial replacement of cement in mortar and concrete, basically, the strength development of GBFS blended concrete and cement are reviewed in this study. These test results confirmed that the strength of cement mortar and concrete is varied with percent of slag replacement, fineness of slag and cement used, curing temperature as well as curing method. Based on the information available in literature, slag and slag cement could be a valuable material for the production of sustainable concrete.

Abstract: Chemical and mineral compositions, the surface morphology of steel slag were evaluated in this study. On this basis, treatment effect of acidic Zn²⁺-containing wastewater was investigated using the slag as a water treatment material, and then mechanism of removal Zn²⁺ was discussed. The results showed steel slag was a suitable material for treatment of acidic heavy mental wastewater. Under conditions of slag size fraction of -1.2+0.15mm, slag concentration of 30 g∙L^-1, stirring speed of 150rpm for 30 min, removal rate of Zn²⁺ was 98.59%, Zn²⁺ concentration in wastewater was reduced from 100 mg/L to 1.41 mg/L, and pH value was increased from 2 to 6.4. Filtrate after treatment reached the first discharge standard in integrated wastewater discharge standard (GB8978-1996). Appearance of Zn (OH)₂ diffraction peaks in XRD pattern showed that Zn (OH)2 had covered on steel slag surface, and Zn²⁺ removal included four main processes: production of OH- from hydration reaction of a_{Subscript text}ctive calcium silicate in steel slag, generation of Zn (OH)₂ precipitation in wastewater, adsorption and settlement of Zn (OH)₂ on surface of steel slag and removal of Zn (OH)₂ from wastewater by filtration.