An Influence of a Binder System to the Rheological Behavior of the SS316L Metal Injection Molding (MIM) Feedstock

2011 ◽  
Vol 264-265 ◽  
pp. 554-558 ◽  
Author(s):  
Khairur Rijal Jamaludin ◽  
Norhamidi Muhamad ◽  
Hooman Abolhasani ◽  
Hadi Murthadha ◽  
Mohd Nizam Ab. Rahman
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Injection Molding ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Binder System ◽  
Flow Behavior Index ◽  
Injection Molded

The influence of a binder system to the rheological behavior of a Metal Injection Molding (MIM) feedstock is presented in the paper. The binder systems used are: a) PEG & PMMA b) Palm stearin & LLDPE and, c) Tapioca starch & LLDPE. The viscosity and shear rate of the feedstocks were measured at various range of temperature and shear rate across the L/D = 10 capillary rheometer. The flow behavior index, n and activation energy, E of each feedstock were measured to show its significance as MIM feedstock. Generally, the result indicates all feedstock exhibits a shear thinning behavior and the binders are suitable as MIM binder. Additionally, the present paper has discovered that the binder system does not have much influence to the activation energy. In order to show the relevance of the rheological behavior to the actual injection molding performance, green parts has been injection molded and the result shows an agreement with the rheological behavior result.

INFLUENCE OF SPACE HOLDER ON RHEOLOGICAL BEHAVIOR OF COPPER FEEDSTOCKS FOR METAL INJECTION MOLDING

2015 ◽  
Vol 76 (6) ◽  
Author(s):  
Mohammad Dahar Kamal Bahrin ◽  
Nor ‘Aini Wahab ◽  
Nor Amalina Nordin ◽  
Muhammad Hussain Ismail ◽  
Ismail Nasiruddin Ahmad
Keyword(s):  
Injection Molding ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Plastic Behavior ◽  
Flow Behavior Index ◽  
Space Holder ◽  
Porous Copper

The characterization of MIM feedstock consisting of 63 vol% of copper powder with a binder system consisting of palm stearin (PS) and low density polyethylene (LDPE) was studied. To achieve porous structure, sodium chloride (NaCl) was added as a space holder. The effect of shear rate (s-1), temperature (oC) and viscosity (Pa.s) on the rheological behavior of solid and porous copper feedstocks were investigated by using the Rosand RH2000 Capillary Rheometer at temperatures of 160, 170 and 180oC. The feedstocks achieved desirable injection molding characteristics such as pseudo-plastic behaviour, stable flow, flow behavior index less than 1 (n<1) and low activation energy (E). It can be concluded from the analysis that both feedstocks showed a good pseudo-plastic behavior within acceptable ranges in MIM. 

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.

Development of a Starch-Based Binder in Metal Injection Molding

2009 ◽  
Vol 83-86 ◽  
pp. 24-30 ◽  
Author(s):  
Norhamidi Muhamad ◽  
Hooman Abolhasani
Keyword(s):  
Injection Molding ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Steel Powder ◽  
Metal Injection Molding ◽  
Linear Low Density Polyethylene ◽  
Flow Behavior Index ◽  
Different Temperatures ◽  
316 L Stainless Steel ◽  
Behavior Index

A new starch-based binder as a natural polymer has been developed for metal injection molding (MIM). In this study tapioca starch which is cheap and readily available in Malaysia has been used as a binder which composed of starch, glycerol, linear low density polyethylene (LLDPE), citric acid and stearic acid. This developed binder system was mixed with 316 L stainless steel powder to prepare the feedstock at three different of powder loadings of 56, 57 and 58% vol. The rheological behavior of the binder and feedstock were evaluated at different temperatures using a capillary rheometer. The rheological behavior of binder shows less than 10 Pa s and the flow behavior index of the feedstocks were determined to less than 1, which indicates the flow characteristic is pseudo-plastic which is suitable for MIM process. Finally, among these three feedstocks, the feedstock of 57% vol. powder loading was selected and its viscosity values within expected shear rate range are less than 1000 Pa s.

Glycerol as Plasticizer for Waste Polystyrene Based Metal Injection Molding (MIM) Binder

2013 ◽  
Vol 845 ◽  
pp. 837-840 ◽  
Author(s):  
Nurul Nadzirah Ismail ◽  
Khairur Rijal Jamaludin ◽  
Norhayati Ahmad
Keyword(s):  
Activation Energy ◽  
Injection Molding ◽  
Rheological Properties ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Waste Polystyrene

Except for the binder characteristics and molding conditions, the powder loading has a very important effect on the compact distortion. Three types of feedstocks consist of water atomised SS316L powder with 55% waste polystyrene, 35% palm stearin and 10% glycerol were prepared. The powder loading of each feedstocks are 63%, 64% and 65% respectively. Effect of glycerol at different powder loading on rheological properties in term of flowability (n), activation energy (E) and moldability (α) were investigated. It has been observed that all feedstocks possess pseudoplastic flow behavior which is one of the most crucial requirements in MIM process. The addition of glycerol decreases the flowability index while increased the activation energy.

scholarly journals Study on Stability of a Novel Binder System Based on Palm Stearin in Metal Injection Moulding Application

2007 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Muhammad Hussain Ismail ◽  
Norhamidi Muhamad ◽  
Aidah Jumahat ◽  
Istikamah Subuki ◽  
Mohd Afian Omar
Keyword(s):  
Injection Molding ◽  
Flow Characteristics ◽  
Injection Pressure ◽  
Palm Stearin ◽  
Steel Powder ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Flow Activation Energy

Metal Injection Molding (MIM) is a wellestablished technology for manufacturing a variety of complex and small precision parts. In this paper, fundamental rheological characteristics of MIM feedstock using palm stearin are theoretically analyzed and presented. The feedstock consisted of gas atomized 316L stainless steel powder at three different particle size distributions and the binder system of palm stearin (PS) and polyethylene (PE). The powder loading used was 60vol % for all samples (monosize 16 µm, monosize 45 µm, and bimodal 16 µm + 45 µm) and the binder system of 40vol %(PS/PE = 40/60). The viscosity of MIM feedstock at different temperatures and shear rates was measured and evaluated. Results showed that, the feedstock containing palm stearin exhibited suitable rheological properties by increasing the fluidity of feedstock in MIM process. The rheological results also showed a pseudoplastic flow characteristics, which poses higher value of shear sensitivity (n) and lower value of flow activation energy (E), that are both favourable for injection molding process. The green parts were successfully injected and exhibited adequate strength for handling by optimizing the injection pressure and temperature.

Rheological Properties of Copper-Graphite MIM Feedstocks Prepared with Waste PET Binder

2014 ◽  
Vol 660 ◽  
pp. 209-213 ◽  
Author(s):  
Mohammad Fadhil Mat Nor ◽  
Safian Sharif ◽  
Khairur Rijal Jamaludin
Keyword(s):  
Shear Rate ◽  
Injection Molding ◽  
Rheological Properties ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Capillary Rheometry

In this study, waste polyethylene terephthalate (PET) polymer binder systems were used to prepare copper-graphite metal injection molding (MIM) feedstock. A mixer and screw extrusion were used to achieve optimized feedstock, and the rheological properties of the resulting fluids were evaluated using a capillary rheometry to simulate the injection molding process. The solid loadings in the copper-graphite mixes were investigated in the ranges of 51-53% using PET binder system. The effects of shear rate (γ), solid volume fraction (φ) and temperature (T) on the rheological behavior of the copper/graphite MIM feedstocks are discussed.High viscosity trend was notably recorded as shear rate increased relatively. The results indicated that this feedstock system shows dilatant characteristic and lots of further work shall be conducted in attempt to establish this as an ideal binder system.

Dynamic Response Optimization for Cemented Carbide Injection Molding

2014 ◽  
Vol 68 (4) ◽  
Author(s):  
Sri Yulis M. Amin ◽  
Norhamidi Muhamad ◽  
Khairur Rijal Jamaludin
Keyword(s):  
Injection Molding ◽  
Palm Stearin ◽  
Processing Parameters ◽  
Cemented Carbide ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Molding Process ◽  
Response Optimization ◽  
Injection Molded ◽  
Injection Temperature

The need to optimize the injection molding parameters for producing cemented carbide parts via Metal Injection Molding process is crucial to ensure the system’s robustness towards manufacturer and customer’s satisfactions. Defect free product with best density can be produced while reducing time and cost in manufacturing. In this work, the feedstock consisting of WC-Co powders, mixed with palm stearin and polyethylene binder system was injection molded to produce green parts. Several processing variables, namely powder loading, injection temperature, holding pressure and flowrate, were optimized towards the density of the green body, as the response factor. By considering humidity level at morning and evening conditions as the noise factor, the results show the optimum combination of injection molding parameters that produces best green density. The green part exhibited best density by following this optimum processing parameters, A2B3C1D1, that are flowrate at 20 ccm/s, powder loading at 63% vol., injection temperature at 140°C, and holding pressure at 1700 bar.

scholarly journals Study on Stability of a Novel Binder System Based on Palm Stearin in Metal Injection Moulding Application

2007 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Muhammad Hussain Ismail ◽  
Norhamidi Muhamad ◽  
Aidah Jumahat ◽  
Istikamah Subuki ◽  
Mohd Afian Omar
Keyword(s):  
Injection Molding ◽  
Flow Characteristics ◽  
Injection Pressure ◽  
Palm Stearin ◽  
Steel Powder ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Flow Activation Energy

Metal Injection Molding (MIM) is a wellestablished technology for manufacturing a variety of complex and small precision parts. In this paper, fundamental rheological characteristics of MIM feedstock using palm stearin are theoretically analyzed and presented. The feedstock consisted of gas atomized 316L stainless steel powder at three different particle size distributions and the binder system of palm stearin (PS) and polyethylene (PE). The powder loading used was 60vol % for all samples (monosize 16 µm, monosize 45 µm, and bimodal 16 µm + 45 µm) and the binder system of 40vol %(PS/PE = 40/60). The viscosity of MIM feedstock at different temperatures and shear rates was measured and evaluated. Results showed that, the feedstock containing palm stearin exhibited suitable rheological properties by increasing the fluidity of feedstock in MIM process. The rheological results also showed a pseudoplastic flow characteristics, which poses higher value of shear sensitivity (n) and lower value of flow activation energy (E), that are both favourable for injection molding process. The green parts were successfully injected and exhibited adequate strength for handling by optimizing the injection pressure and temperature.

scholarly journals Aqueous Solutions of Polyethoxylated Fatty Alcohols Rheological behavior and superficial properties

2019 ◽  
Vol 70 (2) ◽  
pp. 382-386
Author(s):  
Andra Tamas ◽  
Sabina Nitu
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Aqueous Solutions ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Fatty Alcohols ◽  
Flow Behavior Index ◽  
Foaming Power ◽  
Newtonian Behavior ◽  
Behavior Index

The paper presents the study of the rheological and superficial behavior (foaming power and wetting capacity) of some aqueous solutions with polyethoxylated fatty alcohols content. The influence of fatty alcohols concentration and their degree of ethoxylation as well as that of temperature on the rheological behavior was determined from the dependences between the shear stress t and the shear rate. The results demonstrate that all the studied solutions have non-Newtonian behavior, with flow behavior index smaller than 1.

Rheological Behavior of Yttria Stabilized Zirconia (YSZ) Feedstock for Ceramic Injection Moulding (CIM) Process

2017 ◽  
Vol 882 ◽  
pp. 119-123
Author(s):  
Mahfuzah Zainudin ◽  
Muhammad Hussain Ismail
Keyword(s):  
Rheological Behavior ◽  
Injection Moulding ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Stabilized Zirconia ◽  
Flow Behavior Index ◽  
Green Strength ◽  
Ceramic Injection Moulding ◽  
Behavior Index

The characterization of CIM feedstock consisting 58, 59, 60vol% of YSZ powder with binder system comprising a palm stearin (PS) and low density polyethylene (LDPE) were studied. The effects of powder loading and temperature (°C) on the rheological behavior of the YSZ were investigated by using Rosand RH2000 Capillary Rheometer. The results showed all the feedstock achieved desirable injection moulding characteristics such as pseudoplastic behavior, flow behavior index (n) less than 1 and low activation energy (E). The rectangular parts were successfully injected moulded at optimum temperature of 170°C with the highest green strength was 12.7 N, obtained from 60 vol% powder loading which correspond to greater density and low porosity of the samples.

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