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This paper investigates the performance of feedstock characteristics for micro metal injection molding (μMIM) by using optimum power loading variation and rheological characterization. The study has been emphasized on the powder and binder system in which stainless steel SS316L powder are mixed with composite binder, which consists of PEG (Polyethelena Glycol), PMMA (Polymethyl Methacrilate) and SA (Stearic Acid) by variation of powder loading concentration. The rheology properties are investigated using Shimadzu Flowtester CFT-500D capillary rheometer. As the geometry of water atomised stainless steel powder are irregular shape, therefore it is expected significant changes in the rheological results that can influence the microcomponent, surface quality, shape retention and resolution capabilities. The optimization of the μMIM rheological properties as a function of stainless steel powder loading concentration are evaluated by flow behavior exponent, activation energy and moldability index. From the results, it shows that 61.5%vol contributes a significant stability over a range of temperature and the best powder loading from a critical powder volume percentage (CPVP) and rheological point of view.

Self-Compacting Concrete (SCC) is a flowing mixture that consolidates under its own weight and a highly workable concrete that can flow through densely reinforced and complex structural elements. The source material like a granular aggregate is often used in construction but difficult to find and the price is expensive. In developing country like Malaysia, the demand of natural sand is quite high to the rapid infrastructural growth. The aims for this paper is to study the effect of coal bottom ash on the replacement level of coal bottom ash as partial replacement of fine aggregate in SCC and to investigate the effect of coal bottom ash on the split tensile strength. The test involved designation of 0%, 10%, 20% and 30% of coal bottom ash (CBA) as a partial replacement of fine aggregate with variation of water cement ratio of 0.35, 0.40 and 0.45. The results shows that slump flow, Lbox ratio and sieve segregation resistance of SCC mixtures with CBA are decreased, while T 500 slump flow time increased with the increase of CBA replacement level. The highest tensile strength of SCC is 4.25 MPa achieved by control sample with the water cement ratio of 0.35 at the age 28 days. The increment of CBA replacement levels resulted in the reduction of split tensile strength and density of SCC. Meanwhile, the increment of water cement ratio was reduced the split tensile strength of SCC.

Abstract:A hydroxyapatite is known as one of vital materials and common use in biomedical field and concentrated in clinical area. In relation to the above, the development of hydroxyapatite powder becomes an attractive research lines due to simplify in produce it. Thus in this paper the researcher stress out about Hydroxyapatite powder gained from the natural sources or so called as the waste of Tilapia bone and scales. The raw bones of and scale were undergo to crushing process to form in powder size (0.2 mm) then analysed by X-ray Diffraction (XRD) to identified the mineralogy of raw bone. Moreover the powder of fish bone and scales also go through to Scanning Electron Microscope (SEM) machine to analyse the microstructure of the powder while EDS act as device to determine the chemical composition of the sample powder. Sample powder then forward calcination process at selected temperature range to as a cheaper method in obtained hydroxyapatite raw sources. The range ofcalcination temperatures are between 800˚C to 1000˚C.The sample preparation were analysed in both condition before and after calcination process by using XRD, SEM and EDS.The HAP crystalline composition of tilapia bones for raw powder and at 800 ˚C are similar with HAP pattern (JDS 00-009-0432) and the chemical reaction is Ca 5 (PO4) 3 (OH) then at temperature 900 and 1000 similar to HAP pattern (JDS 00-055-0592) with chemical reaction equal to Ca 10 (PO4) 6 (OH) 2 .

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Micro metal injection molding which is a new develop technology has attract most researcher where it becomes among the promising method in powder metallurgy research to produce small-scale intricate part at an effective process and competitive cost for mass production. Due to highly stringent characteristics of micro MIM feedstock,the study has been emphasized in investigating the optimization of highest green strength which plays an important characteristic in determining the successful of micro MIM. Stainless steel SS 316L with D50 = 5.96μm was used with composite binder, which consists of PEG, PMMA and Stearic Acid. From rheological characteristic and highly significant parameter through screening experiment, feedstock with 61.5% with several injection parameters were optimized such as injection pressure(A), injection temperature(B), mold temperature(C), injection time(D) and holding time(E). Besides that, interaction effects between injection pressure, injection temperature and mold temperature were also considered to optimize in the Taguchi’s orthogonal array. Analysis of variance (ANOVA) in terms of signal-to-noise ratio (S/N-larger is better) for green strength was also presented in this paper. Result shows that interaction between injection temperature and mold temperature(BxC) give highest significant factor followed by interaction between injection pressure and injection temperature(AxB). Single factor that also contributes to significant optimization are mold temperature(C), injection time(D) and injection pressure(A). This study shows that Taguchi method would be among the best method to solve the problem with minimum number of trials.

Development and characterization of polymers-metallic hot embossing process for manufacturing metallic micro-parts AIP Conf.Abstract. Micro metal injection molding (µMIM) which is a variant of MIM process is a promising method towards near net-shape of metallic micro components of complex geometry. In this paper, µMIM is applied to produce 316L stainless steel micro components. Due to highly stringent characteristic of µMIM properties, the study has been emphasized on optimization of process parameter where Taguchi method associated with Grey Relational Analysis (GRA) will be implemented as it represents novel approach towards investigation of multiple performance characteristics. Basic idea of GRA is to find a grey relational grade (GRG) which can be used for the optimization conversion from multi objectives case which are density and strength to a single objective case. After considering the form "the larger the better", results show that the injection time(D) is the most significant followed by injection pressure(A), holding time(E), mold temperature(C) and injection temperature(B). Analysis of variance (ANOVA) is also employed to strengthen the significant of each parameter involved in this study.

Taguchi method of L 27 (3 13 ) orthogonal array is used in this paper as a tool in optimization of Metal injection molding (MIM) parameters for the highest green strength. Parameters optimized are the injection pressure, injection temperature, powder loading, mold temperature, holding pressure and injection speed. Besides those, interaction of the injection pressure, injection temperature and powder loading were studied. The metal powder of Ti-6Al-4V is mixed with binder 60wt% of palm stearin and 40wt% of polyethylene successfully injected at optimum parameter condition: 350 bar of injection pressure, 140 o C of injection temperature, 65vol% of powder loading, 50 o C of mold temperature, 600 bar of holding pressure, and 10 ccm/s of the injection rate. Analysis of variance (ANOVA) for the best signal to noise ratio (S/N) presents the contribution of the parameters to the quality characteristic (green strength). Results show that the mold temperature has highest significant percentage (27.59%) followed by powder loading (15.44%) and injection pressure (12.30%). Nevertheless, the analysis of variance does not show any contribution from interaction.