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.

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 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 Preparation of Ss 316l Feedstock for Metal Injection Molding (Mim) Process

2019 ◽  
Vol 8 (10) ◽  
pp. 1559-1563
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Mixing Time ◽  
Steel Powder ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Custom Made ◽  
316L Steel

The purpose of this paper is to make the homogeneous mixing of SS 316L steel powder with a multiple binder system in a custom made mixing machine by varying the process parameters like speed, Temperature and time as the homogeneity impacts on the final product in the MIM process. A homogeneous mix of metal powder and binder is essential in metal injection molding process as it affects the product quality significantly. This paper aims at design of new mixing equipment and characterization of SS 316L feed stock. A mixing machine of 2 kg capacity is designed and fabricated to prepare a homogeneous mix of SS 316l material with a multiple binder system. Mixing time, mixing speed and Temperature of Barrel are considered as process parameters. Taguchi techniques are used to optimize the process parameters .The RPM of the blade is varied from 20 to 40 in steps of 10, the temperature is varied from 200 to 240 in steps of 20 and the mixing time is varied from 20 to 40 minutes in steps of 10. The results of the experimentation reveals that mixing temperature has a profound effect on the homogeneity of the mix.

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.

The Influence of Single Based Binder of Palm Stearin in HAP Feedstock on Rheological Properties Used for Ceramic Injection Moulding (CIM)

2015 ◽  
Vol 1134 ◽  
pp. 220-224
Author(s):  
Siti Norazlini Abd Aziz ◽  
Nurul Huda M. Ali ◽  
Mimi Azlina Abu Bakar ◽  
Istikamah Subuki ◽  
Muhammad Hussain Ismail
Keyword(s):  
Injection Molding ◽  
Injection Moulding ◽  
Palm Stearin ◽  
Injection Molding Process ◽  
Capillary Rheometer ◽  
Binder System ◽  
Molding Process ◽  
Main Interest ◽  
Biomedical Implant ◽  
Ceramic Injection Moulding

Development of binder system based on natural resources is one the main interest among researchers in ceramic injection moulding (CIM) with the main aim of processibility of complex biomedical implant. In this paper, the influence of single binder comprised of palm stearin mixed with HAP powder was investigated. The powder and binder mixture, generally known as feedstock was analyzed for its flowability in order to get some insight for injection moulding purposes. Two different mixing temperatures were investigated for preparing the feedstock; 160°C and 70°C. The feedstocks viscosity was then evaluated using a capillary rheometer at temperature range from 70°C to 90°C. The results clearly showed that the use of 100% palm stearin was promising in providing required pseudoplastic flow for injection molding. The injection molding process can be carried out at relatively low temperature in comparison with the conventional binder systems used.

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