Pemilihan Bahan Suapan bagi Proses Pengacuan Suntikan Logam Berdasarkan kepada Kajian Sifat Reologi

2012 ◽  
Author(s):  
Norhamidi Muhamad ◽  
Khairur Rijal Jamaludin ◽  
Sri Yulis M. Amin ◽  
Mohd Nizam Ab. Rahman
Keyword(s):  
Stainless Steel ◽  
Injection Molding ◽  
Rheological Properties ◽  
Polymethyl Methacrylate ◽  
Fine Powder ◽  
Flow Behaviour ◽  
Metal Injection Molding ◽  
Coarse Powder ◽  
Flow Behaviour Index ◽  
Behaviour Index

Sifat reologi bahan suapan acuan suntikan logam MIM yang disediakan dengan keluli tahan karat 316L pengabusan gas dan, polymethyl methacrylate (PMMA), polietelena glikol (PEG) dan asid sterik sebagai bahan pengikat telah dikaji. Dai kapilari L/D = 10 telah digunakan dalam kajian ini. Serbuk keluli tahan karat kasar dan halus telah diadunkan dengan bahan pengikat pada beban serbuk 64% dan 65% isipadu. Kesemua bahan suapan mempamerkan tingkahlaku pseudo plastik memandangkan indek tingkahlaku alirannya kurang daripada 1, tetapi indek tersebut berkadar songsang terhadap beban serbuk. Seterusnya, indek tingkahlaku bagi serbuk kasar didapati lebih besar berbanding serbuk halus. Bahan suapan 16_64 lebih peka berbanding bahan suapan yang lain, dan bahan suapan 31_65 pula didapati kurang peka terhadap suhu dan tekanan. Bagaimanapun, kepekaan juga didapati berkadar songsang terhadap beban serbuk. Maka, indek kebolehacuan bagi 31_64 adalah yang terbaik, dan hasil kajian mendapati bahawa beban serbuk 64% isipadu menghasilkan kebolehacuan bahan suapan yang lebih baik. Akhirnya, kajian ini menyimpulkan bahawa kesemua bahan suapan sesuai untuk disuntik ke dalam acuan kerana sifat reologinya menunjukkan penipisan ricih apabila tegasan ricih dikenakan terhadapnya. Bagaimanapun, bahan suapan pada beban serbuk 64% isipadu adalah yang lebih sesuai disebabkan oleh indek kebolehacuan yang lebih tinggi daripada 65% isipadu. Kata kunci: Pengacuan suntikan logam, reologi, indek tingkahlaku aliran, tenaga pengaktifan, indek kebolehacuan Rheological properties of the metal injection molding (MIM) feedstock prepared with gas atomized 316L stainless steel and, polymethyl methacrylate (PMMA), polyethylene glycol (PEG) and stearic acid as binder have been investigated. Capillary rheometer with die of L/D = 10 was used in the investigation. Coarse and fine stainless steel powders were mixed with binders at powder loading of 64% and 65% volume. All feedstocks exhibit pseudo plastics behaviour as the flow behaviour indexes were less than one, but it is inversely proportional to the powder loading. Moreover, the flow behaviour index of the coarse powder is larger than the fine powder particles. Feedstock 16_64 exhibits higher sensitivity among other feedstocks while 31_65 was least sensitive to the temperature and pressure. However, the sensitivity was also inversely proportional to the powder loading. Thus, moldability index of the 31_64 is the best and result shows that powder loading 64% volume gives better moldability to the feedstocks. Finally, the investigation concluded that the feedstocks are suitable to be injection molded because the rheological properties demonstrate a shear thinning when subjected to shear stress. However, feedstock with the powder loading of 64% volume is the most suitable as the moldability index is higher than the 65% volume feedstocks. Key words: Metal injection molding, rheology, flow behaviour index, activation energy, moldability index

Rheological Investigation of Water Atomized Metal Injection Molding (MIM) Feedstock for Processibility Prediction

2009 ◽  
Vol 83-86 ◽  
pp. 945-952 ◽  
Author(s):  
Khairur Rijal Jamaludin ◽  
Norhamidi Muhamad ◽  
Mohd Nizam Ab. Rahman ◽  
Murtadhahadi ◽  
Sufizar Ahmad ◽  
...  
Keyword(s):  
Injection Molding ◽  
Rheological Properties ◽  
High Temperatures ◽  
Fine Powder ◽  
Metal Injection Molding ◽  
Coarse Powder ◽  
Composite Binder ◽  
Powder Feedstock ◽  
O 63

This paper presents the rheological properties of SS316L water atomized MIM feedstock. Coarse and fine SS316L water atomized powder is mixed with a composite binder consisting of PMMA and PEG to form a homogenous paste, termed as feedstock. The feedstock is loaded with SS316L water atomized powder ranging 62 v/o, 62.5 v/o, 63 v/o, 63.5 v/o and 64 v/o. However, due to the morphology of the water atomized powder which is not spherical compared to the gas atomized ones, fine powder feedstock is unable to produce any significant rheological result due to the powder loading being more than 63.5 v/o. Results show that the fine powder feedstock demonstrates a higher viscosity if compared to the coarse powder feedstock. It can be established that binder separations are likely to occur in the coarse powder feedstock, especially, at high temperatures. The investigation concludes that the fine powder feedstock has its best rheological properties at 62 v/o while the coarse powder feedstock lies between 63 v/o and 63.5 v/o.

Characterization and Rheological Studies on Ready-Made Feedstock of Stainless Steel 316L in Metal Injection Molding (MIM) Process

2013 ◽  
Vol 465-466 ◽  
pp. 709-714 ◽  
Author(s):  
N.H. Mohamad Nor ◽  
Muhammad Hussain Ismail ◽  
Nur Atikah Abu Kasim ◽  
N. Muhamad ◽  
M.A. Taib
Keyword(s):  
Stainless Steel ◽  
Current Trend ◽  
Metal Injection Molding ◽  
Total Weight Loss ◽  
Capillary Rheometer ◽  
Stainless Steel 316L ◽  
Flow Behaviour Index ◽  
Crucial Part ◽  
Advanced Applications ◽  
Behaviour Index

Current trend for manufacturers associated to MIM industry try to enhance the feedstock in term of its characteristics, since it is the most crucial part of the MIM process. This paper covered the characterization and rheological studies on a ready-made feedstock of stainless steel 316L which is vital to determine the availability and suit the needs of many advanced applications. There are three different experiments involved which are Scanning Electron Microscope (SEM), Differential Scanning Calorimeter (DSC), Thermogravimetric (TGA) and Capillary Rheometer. Observation through SEM gives an insight of the bonding microstructure matrices of the feedstock and also determines the homogeneity of the feedstock. DSC testing defines the melting temperature of the 3 binders used which are 62.07°C for surfactant, 178.72°C for filler and 236.61°C for backbone binder. From TGA result, it showed that the total weight loss of feedstock was 39%. Throughout the capillary rheometer testing, the feedstocks viscosity was decreasing as the shear rate increasing. The feedstock exhibits pseudoplastic behaviour since its flow behaviour index was less than 1. It is founded that at the temperature of 190°C, the feedstock exhibits the best characteristics for injection.

scholarly journals Use of helical ribbon mixer for measurement of rheological properties of fruit pulps

2013 ◽  
Vol 19 (No. 4) ◽  
pp. 148-153 ◽  
Author(s):  
P. Novotná ◽  
A. Landfeld ◽  
K. Kýhos ◽  
M. Houška ◽  
J. Strohalm
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Flow Behaviour ◽  
Rotational Rheometer ◽  
Shear Rates ◽  
Coaxial Cylinders ◽  
Helical Ribbon ◽  
Flow Behaviour Index ◽  
Average Shear ◽  
Behaviour Index

Fruit pulps contain fine particles of the flesh of the original fruit that are suspended in the fruit juice. This suspension has a tendency to settling or separation during measurements of its rheological properties in the rotational rheometer with coaxial cylinders (especially if the greater gap is used). In this case the use of a mixer is convenient. The mixer can serve as a tool for measurement of rheological properties and at the same time it can prevent the settling and it is not sensitive to the occurrence of greater particles in the measured fluid. The helical ribbon mixer was used in this work for measurement of five samples of fruit pulp. The mixer was calibrated by the use of Newtonian fluid of known viscosity (honey). The radius of the inner cylinder of hypothetical rotational rheometer was predicted from the assumption that mixer and cylinder exhibit the same torque necessary for the rotation at the same rotational speed. The average shear rate in the mixed pulp was predicted by using the relation valid for power law fluids and rheometer with coaxial cylinders. The radius (where the average shear rate was calculated) was chosen by the requirement that the shear rate would be almost independent of changes in the flow behaviour index valid for measured pulps. Firstly the flow behaviour index was predicted as a slope of torque vs. rotational speed dependence in log-log co-ordinates. It was found that the flow behaviour index varies in the range 0.2–0.3. The radius was predicted from a graph where shear rates for 0.2 and 0.3 are the same. Then the average shear rates were calculated from rotational speeds for individual flow behaviour indexes. Rheological properties measured by using a mixer correspond to those measured with a rotational rheometer with coaxial cylinders satisfactorily only in the case that the creeping flow regime was kept in the mixed fluid. The fruit pulps are strongly non-Newtonian fluids with very low values of the flow behaviour index around 0.2.

Injection Moulding of A Bimodal Size Distribution 316L Stainless Steel Powders

2012 ◽  
Author(s):  
M.A. Omar
Keyword(s):  
Stainless Steel ◽  
Polyethylene Glycol ◽  
Polymethyl Methacrylate ◽  
Injection Moulding ◽  
Raw Materials ◽  
Fine Powder ◽  
Steel Powder ◽  
Water Leaching ◽  
Coarse Powder ◽  
Metal Injection Moulding

Bagi mengurangkan kos bahan mentah untuk proses pangacuan suntikan logam (MIM), bahan teracu yang diperbuat daripada serbuk logam keluli tahan karat dengan nisbah serbuk logam kasar dan halus yang berlainan telah diselidiki. Bahan suapan tersebut disediakan dengan menggunakan sistem bahan pengikat komposit yang terdiri sebahagian besarnya polietilina glikol (PEG) yang berlainan berat molekulnya dan emulsi polimetil metakrilat (PMMA) yang seterusnya disuntik ke dalam bentuk segiempat tepat dengan suhu muncung suntikan logam pada 140°C. Hasil ujikaji menunjukkan kekuatan bahan teracu meningkat secara linear dengan peningkatan nisbah serbuk halus di dalam campuran dan optimum pada 30 wt.% dan seterusnya berlaku penurunan dengan peningkatan nisbah serbuk halus. Peningkatan serbuk logam halus di dalam campuran juga dapat meningkatkan ketumpatan akhir dan kekerasan bahan tersinter. Kadar penyingkiran polietilina glikol semasa proses pengurasan air meningkat dengan penurunan nisbah serbuk logam halus yang mana menunjukkan bahawa serbuk logam kasar memberi kesan ketara ke atas proses penyingkiran bahan pengikat. Kata kunci: pengacuan suntikan logam; polietilina glikol; polimetil metakrilat; pengurusan air; pengsinteran In an effort to lower the cost of raw materials of metal injection moulding (MIM), a moulded part made of a different ratio of coarse and fine stainless steel powder mixtures, ranging from 10 to 50 wt.% of fine powder were investigated. The feedstocks were prepared using a composite binder system which consist of a major fraction of polyethylene glycol (PEG) with different molecular weight and a minor fraction of polymethyl methacrylate (PMMA) emulsion and subsequently moulded into a rectangular shape at the nozzle temperature of 140°C. The results show that the green strength of the moulded part increased linearly with the increased of the ratio of fine powder to an optimum of 30 wt.% and decreased slightly with the increased of coarse/fine ratio. An increase in the fine powder in the mixture, improved the final densification and hardness of the sintered parts. The rate of PEGs removed during water leaching substantially increased with the lower ratio of fine powder, which suggest that the coarse powder has significant influence on the removal of the binder. Key words: metal injection moulding; polyethylene glycol; polymethyl methacrylate; water leaching; sintering

scholarly journals A comparative study on the rheological properties of coal water slurries using sodium tripoly-phosphate and carboxy-methyl-cellulose as dispersants

2021 ◽  
Vol 69 (3) ◽  
pp. 100
Author(s):  
M. Ananda Rao ◽  
M. V. Pavan Kumar ◽  
Lenka Srinu
Keyword(s):  
Rheological Properties ◽  
Apparent Viscosity ◽  
Methyl Cellulose ◽  
Flow Behaviour ◽  
Solid Loading ◽  
Carboxy Methyl Cellulose ◽  
Flow Behaviour Index ◽  
Coal Particles ◽  
Behaviour Index ◽  
Carboxy Methyl

The effects of two anionic dispersants (polymeric-carboxy methyl cellulose: CMC and inorganic-sodium tripolyphosphate: STPP) on the rheological properties of coal water slurries (CWS) of varying solid loading were reported and compared. The rheological data was obtained in the shear rate range of 60-160 s<sup>-1</sup> and the data was fitted using power law model. For lower solid concentrations (10% and 20%), shear thickening behaviour was observed while shear thinning nature was seen for the higher solid loadings (30%,40% and 50%) for CWS with both the dispersants. For all slurries, an increase in flow behaviour index values was seen with the increase of dispersant loading. For CWS of 10% and 20% solid loadings, lower values of flow behaviour index was observed with CMC as dispersant. On the other hand, lower values for flow behaviour index was seen with STPP as dispersant for CWS of 30%, 40% and 50% solids loading. Although CMC was found very effective in reducing the apparent viscosity at lower dosages unlike STPP, the apparent viscosity values are quite sensitive to the loading of CMC as dispersant in comparison to STPP. This observed trend may be due to aggressively induced negative charges upon the adsorption of CMC on coal particles at the tested dispersant dosages.

The Influence of Sewage Fat Composition on Rheological Behavior of Metal Injection Moulding

2014 ◽  
Vol 660 ◽  
pp. 38-42 ◽  
Author(s):  
Azriszul Mohd Amin ◽  
Mohd Halim Irwan Ibrahim ◽  
Rosli Asmawi ◽  
Najwa Mustapha
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Injection Moulding ◽  
Rheological Characteristic ◽  
Flow Behaviour ◽  
Characteristic Analysis ◽  
Metal Injection Moulding ◽  
Flow Behaviour Index ◽  
Binder Ratio ◽  
Behaviour Index

Influence of sewage ratio or Fat Oil Grease (FOG) on the feedstock rheological characteristic for optimal binder formulation in metal injection moulding is evaluated besides Polypropylene (PP) as a backbone binder. Powder loading of 62% of water atomised SS316L being used here to determine the possibility of the best binder formulation which could be optimised for optimal powder loading base on rheological characteristic analysis. Two binder formulations of PP to SF being selected here are 60/40, 50/50 and 40/60 accordingly with the powder loading of 62% each binder formulation. The analysis will be base on viscosity, shear rate, temperature, activation energy, flow behaviour index and moldability index. It is found that from rheological result views, binder with composition of 60/40 and 50/50 exhibit pseudoplastic behaviour or shear thinning where the viscosity decrease with increasing shear rate. For 40/60 binder ratio is not suitable since the behaviour of the flow indicates dilatants behaviour. After considering all the criteria in terms of flow behaviour index, activation energy, viscosity and mouldability index, binder with ratio of 60/40 is evolve as a good selections.

Effects of Sintering Variables on the Physical and Mechanical Properties of Metal Injection Molding Molded 17-4 PH Stainless Steel

2021 ◽  
Vol 1028 ◽  
pp. 403-408
Author(s):  
Apang Djafar Shieddieque ◽  
Shinta Virdhian ◽  
Moch Iqbal Zaelana Muttahar ◽  
Muhammad Rafi Muttaqin
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Injection Molding ◽  
Relative Density ◽  
Physical And Mechanical Properties ◽  
High Hardness ◽  
Argon Atmosphere ◽  
Metal Injection Molding ◽  
Manufacturing Method ◽  
Small Complex

Metal injection molding (MIM) is a near net shape manufacturing technique for producing small, complex, precision parts in mass production. MIM process is manufacturing method that combines traditional shape-making capability of plastic injection molding and the materials flexibility of powder metallurgy. The process consists of the following four steps: mixing of metal powder and binder, injection molding to shape the component, debinding to remove the binder in the component, sintering to consolidate the debound parts. In this research, the physical and mechanical properties of metal injection molded 17-4 PH stainless steel were investigated with the variation of sintering temperatures (1300 °C - 1360 °C) and atmosphere conditions (argon and vacuum conditions). The relative density, microstructure, distortion, and hardness are measured and analyzed in this study. The results show that highest relative density of 87%, relative homogeneous shrinkage and high hardness are achieved by sintering at 1360 °C for 1.5 hours and argon atmosphere. At the same sintering temperature and time, sintering in vacuum shows lower relative density (81%) than that in argon condition due to pores growth. The pore growths were not observed in the argon atmosphere. It can be concluded that sintering stages more rapidly under vacuum condition. The hardness measurements result also showed that high hardness is obtained by high density parts. The optimum average hardness obtained in this study is 239 HV. However, the hardness properties results are still lower than 280 HV according to MPIF Standard 35 for MIM parts.

The Characterization and Flow Behavior of 316L Stainless Steel Feedstock for Micro Metal Injection Molding (μMIM)

2010 ◽  
Vol 44-47 ◽  
pp. 2872-2876
Author(s):  
Pei Li Haw ◽  
Norhamidi Muhamad ◽  
Hadi Murthadha
Keyword(s):  
Stainless Steel ◽  
Injection Molding ◽  
316L Stainless Steel ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Rheological Characterization

The rheological behaviors of the Micro Metal Injection Molding feedstock are important for the stability of the feedstock during micro injection molding process and quality of the final micro-components. Homogeneous feedstocks are preferable for MIM process to ensure the dimensional consistency of molded components and prevent the defects of powder-binder separation or particle segregation. In this work, feedstocks with various formulations of 316L stainless steel and binder system were prepared by using Brabender Plastograph EC Plus mixer. The binder system comprises of palm stearin, polyethelene (PE) and stearic acid. In order to obtain the viscosity, activation energy, flow behavior and mold ability index, the rheological characterization of the feedstocks were investigated in numerous conditions by using Shimadzu 500-D capillary rheometer The study showed that all of the 316L stainless steel feedstocks are homogenous with pseudo-plastic behaviors.

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