N. Mustafa

Green Strength Optimization in Metal Injection Molding Applicable with a Taguchi Method L9 (3)4

Recently Metal injection molding is selected as a vital process in producing large amount of small part with complex geometry and intricate shape. This process is lead to solve cost effective issue in manufacturing fields. Feedstock composition behavior categorized as one of impact factor in determines the victories in metal injection molding process. Thus this paper is focused on optimizing the strength of green part by applied Taguchi Method L9 (34) as optimization tools during injection process. The composition of feedstock is 55% powder loading (PL) were injected by injection molding machine .Several injection parameter were optimized such as injection temperature (A), barrel temperature (B), injection pressure (C) and Speed (D) The results analyzed by using Signal to Noise Ratio (S/N ratio) terms. The highest green strength is A2, B2, C2, and D2

Hydroxyapatite extracted from waste fish bones and scales via calcination method

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 of calcination 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 Ca5(PO4)3(OH) then at temperature 900 and 1000 similar to HAP pattern (JDS 00-055-0592) with chemical reaction equal to Ca10(PO4)6(OH)2.

Solvent debinding variables on leaching Fat, Oil and Grease (FOG) derivatives of green part stainless steel SS316L metal injection moulding

Sewage fat or Fat Oil Grease (FOG) derivatives for binders component in the stainless steel SS316L feedstock being injected and undergo several test debinding variables. The influences of temperature, time and solvents type has been tested with binder formulation of 60:40 between Polypropylene (PP) and FOG derivatives besides the 60% powder loading of stainless steel powder. Experimental results of the quickest and higher percentage of FOG derivatives leach out from green part is being analysed. The green part will undergo two different solvent debinding (Heptane and Hexane) with three different solvent temperature. Debinding times was set for 10 hours and every 1, 3, 6 and 10 hours the green part will undergo weight measurement for monitoring the weight loss percentage of green part. It seems that both solvent indicates good diffusion and dilution for extracting the FOG derivatives out from the green part in producing brown part where no sign of part crack or swelling during and after solvent debinding. Energy Dispersive Spectrometer (EDS) for element detection and Scanning Electron Microscope (SEM) analysis also being perform which indicates the good pores build up. Results found that the best solvent for removing FOG derivatives is hexane with 60oC being the choice of solvent temperature.

Mixing study of aluminium waste as metal powder for waste polystyrene binder system in Metal Injection Molding (MIM)

The mixing process of a newly developed binder system based on waste polystyrene (PS) and palm kernel oil (PKO) to produce feedstock for metal injection molding (MIM) using aluminium waste as metal powder is described. Since mixing is a critical step in MIM process, therefore the mixture of powder and binder should be homogeneous and moldable. In this study, aluminium powder produced from waste aluminium alloy was mixed with a new binder system consisting of waste polystyrene and palm kernel oil in a Brabender Plastograph EC rotary mixer. Several tests were performed to assess the homogeneity of the feedstock that was produced at 60 vol.% powder loadings.The tests conducted were density, binder burn-out and SEM morphology observation. It was found that the feedstock shows good homogeneity and suitable for further processing in MIM.

Optimisation of Processing Condition Using Taguchi Method on Warpage for HDPE-Clay Composite

Injection molding is one of the most important processes in manufacturing nowadays. Thus, attention must be give towards the optimization of the product defects. Parameters have been chosen by screening tests to improve the process quality. The main purpose of this study is to optimize the processing condition using Taguchi Method on shrinkage for HDPE-Clay specimen. The experiment starts by preparing the mixture between HDPE and clay. Then, screening test is conducted to obtain the parameters. The parameters are melt temperature, injection speed, injection pressure and cooling time. By using the array orthogonal L9 (34), signal to noise ratio and ANOVA were conducted. Based on the S / N ratio analysis, best combination can be produced for warpage (melt temperature: 190°C, injection speed: 40%, injection pressure: 30% and cooling time: 3 seconds). While for ANOVA, melt temperature is most significant with 60.28% for warpage.

Characterization of Stainless Steel 316L Feedstock for Metal Injection Molding (MIM) Using Waste Polystyrene and Palm Kernel Oil Binder System

This paper presents the homogeneity characterisation of MIM feedstock consisting Stainless steel alloy (316 L) powder mix with binder 60wt% of waste polystyrene and 40wt% palm kernel oil. It is one of a critical step that must be conducted in MIM process in order to have a feedstock that is homogeneous and moldable. Water atomised Stainless Steel powder was mixed with the newly developed binder system in a Brabender Plastograph EC rotary mixer. Several tests were performed to assess the homogeneity of the feedstock that was produced at 60 vol % powder loading . The 60 vol.% was chosen because the Critical Powder Volume Concentration (CPVC) of the Powder was found to be 64.8 vol.%. The tests conducted were feedstock density, binder burn-out, rheology and SEM morphology observation. Rheological results exhibited pseudoplastic or shear thinning flow behavior, where its viscosity decreased with increasing shear rate. The feedstock viscosity also decreased with increasing temperature and was found to be suitable for molding. From all the tests conducted, it was found that the feedstock shows good homogeneity and suitable for subsequent processes in MIM.

Solvent Debinding of MIM Parts in a Polystyrene-Palm Oil Based Binder System

The influence of the leaching temperatures on the solvent debinding process of SS316L stainless steel alloy compact has been investigated. Solvent debinding process of injection moulded SS316L feedstock was conducted to eliminate palm kernel oil by using n- heptane solution at various temperatures of 40, 50 and 60°C and at different time duration up to 9 hours. The samples were prepared by injection molding a mixture of stainless steel SS316L alloy with waste polystyrene polymer and palm kernel oil at powder loading 60% vol. The weight loss percentages of palm kernel were calculated and the pore structure evolution was analyzed by scanning electron micrograph to observe the pores created after solvent extraction process. Results show that a complete diffusion of the palm kernel molecules out of the compact part best at 60°C within 6 hours of extraction time

Processability study of Natural Hydroxyapatite and SS316L via metal injection molding

Metal Injection Molding (MIM) process is capable to produces varieties of intricate shape and complex geometry parts in large quantity components at low cost of processing. There are four Major steps in MIM process which is includes of mixing fine metal powders with plastic binder to form a feedstock, injection molding of the green part, extracting the binder, and finally sintering. Thus this paper are concentrate on investigate the processability of Natural Hydroxyapatite and Stainless Steel (SS316L) mixture with an established binder formulation as a feedstock in MIM. The Natural Hydroxyapatite (NHAP) was produced from waste Tilapia Fish Bones. While, Polyethylene (PE) and Palm stearin (PS) acted as a binder system. NHAP/SS316L mixture was successfully injected and established as an appropriate feedstock in MIM. The green strength of ejected part was determined. The maximum force that could attach is 48.1719 N and the maximum stress equal to 6.02Mpa.