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. 

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.

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.

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.

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 Rheological Characterization of Powder Mixture Including a Space Holder and Its Application to Metal Injection Molding

Metals ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 120 ◽  
Author(s):  
Sang Park ◽  
Dongyeong Kim ◽  
Dongguo Lin ◽  
Seong Park ◽  
Seokyoung Ahn
Keyword(s):  
Injection Molding ◽  
Powder Mixture ◽  
Metal Injection Molding ◽  
Rheological Characterization ◽  
Space Holder

scholarly journals Effect of grasshopper (Sphenarium purpurascens Charpentier) paste addition on rheological behavior of Mole Poblano

2021 ◽  
Author(s):  
Eliza Guadalupe Arcos-Estrada ◽  
Mayra Díaz-Ramírez ◽  
Judith Jiménez-Guzmán ◽  
Erika Berenice León-Espinosa ◽  
Mariano García-Garibay ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Design Methodology ◽  
Water Retention ◽  
Flow Behavior ◽  
Rheological Parameters ◽  
Flow Behavior Index ◽  
Emulsifying Capacity ◽  
Behavior Index

Objective: Analyze the effect of grasshopper (Sphenarium purpurascens Charpentier) paste addition on the rheological behavior of Mole Poblano (MP) and its relation with the technological properties of the grasshopper paste. Design/methodology/approach: The addition of grasshopper paste was done at different proportions as follows: T0= 0% of grasshopper paste (GP) and 100% of mole Poblano (MP); T10=10% GP and 90% MP; T15=15% GP and 85% MP, T20=20% GP and 80% MP, T25=25% GP and 75 % MP, T30=30% GP and 70% MP. Water retention and emulsifying capacity of grasshopper paste were evaluated. Density, kinematic and apparent viscosity, and rheological behavior were analyzed at 25ºC; rheological parameters (consistency index (k) and flow behavior index (n)) were calculated by performing a regression analysis to adjust the graphs to a power-law model. Findings/conclusion: Grasshopper paste had higher emulsifying capability than water retention capability.  Apparent viscosity of all formulations decreased as shear rate increased, so all mixtures of GP and MP demonstrated No-Newtonian behavior and pseudoplastic performance. Index consistency increased as GP content increased, these results are related with protein content because GP had a good emulsifying capability. Limitations on study/implications: More studies about the characterization of the proteins of GP and their interaction with other components are required.

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.

Tribology study of hydroxyapatite (HAp) scaffold blended single based binder via rheology and mechanical properties

2017 ◽  
Vol 69 (3) ◽  
pp. 414-419
Author(s):  
Mimi Azlina Abu Bakar ◽  
Siti Norazlini Abd Aziz ◽  
Muhammad Hussain Ismail
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Palm Stearin ◽  
Polymeric Materials ◽  
High Energy ◽  
Single Step ◽  
Injection Molding Process ◽  
Plastic Behavior ◽  
Molding Process ◽  
Content Type

Purpose This paper aims to investigate the vital characteristic of an innovative ceramic injection molding (CIM) process for orthopedic application with controlled porosity and improved tribological and mechanical properties which were affected by complex tribological interactions, whether lubricated like hip implants and other artificial prostheses. The main objective is to maximize the usage of palm stearin as a single based binder as the function of flow properties during injection molding process. Design/methodology/approach The binder used in this present study consists of 100 per cent palm stearin manufactured by Kempas Oil Sdn Bhd and supplied by Vistec Technology Sdn Bhd. The feedstock was prepared by using a Z-blade mixer (Thermo Haake Rheomix OS) and Brabender mixer model R2400. The feedstock prepared was injection molded using a manually operated vertical benchtop machine with an average pressure of about 5-7 bars. The firing step included the temporary holds at intermediate temperatures to burn out organic binders. At this stage, the green molded specimen was de-bound using a single-step wick-debinding method. Findings The maximum content of ceramic material is applied to investigate the efficiencies of net formulation that can be achieved by ceramic materials. The longer the viscosity will change with shear rate, the higher the value of n obtained instead. From the slope of the curves obtained in Figure 3, the value of n for the feedstock was determined to be less than 1, which indicates a pseudoplastic behavior and suitability for the molding process. Moreover, high shear sensitivity is important in producing complex and intrinsic specimens which are leading products in the CIM industry. Originality/value The feedstock containing HAp powder and palm stearin binder was successfully prepared at very low temperature of 70°C, which promoting a required pseudo-plastic behavior during rheological test. The single binder palm stearin should be optimized in other research works carried out, as palm stearin is most preferred compared to other polymeric materials that provided high energy consumption when subjected to the sintering process. Besides the binder is widely available in Malaysia, low cost and harmless effect during debinding process.

scholarly journals Development of Porous Ti-6Al-4V Mix with Palm Stearin Binder by Metal Injection Molding Technique

2015 ◽  
Vol 12 (10) ◽  
pp. 742-751 ◽  
Author(s):  
Mohamad Ikhwan Jamaludin ◽  
Nur Atikah Abu Kasim ◽  
Nor Hafiez Mohamad Nor ◽  
Muhammad Hussain Ismail
Keyword(s):  
Injection Molding ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Porous Ti

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.

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