Effect of Stearic Acid on Rheological Properties of 316L Feedstock for Metal injection Moulding

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Istikamah Subuki ◽  
Muhammad Hussain Ismail ◽  
Amalina Amir ◽  
Mohd Afian Omar
Keyword(s):  
Residual Stress ◽  
Stearic Acid ◽  
Rheological Properties ◽  
Injection Moulding ◽  
Removal Rate ◽  
Extraction Process ◽  
Polymer Mixture ◽  
Metal Injection Moulding ◽  
Negative Effect ◽  
Lower Temperature

Stearic acid (SA) was used as an additive in the process of metal injection moulding (MIM). It was added to the wax/polymer mixture in order to modify the powder wetting, mould lubrication, mixture viscosity, residual stress and debinding behaviour. In this study, the effect of SA in feedstock formulation on mixing torque and rheological properties was investigated. Further, it’s correlation on the as-moulded and as-debound parts behaviour was also investigated. The results showed that addition of SA significantly reduced the mixing torque value and viscosity which correspond to decreasing in inter-particle friction. As a result, injection moulding could be carried out at a lower temperature to achieve sound moulded parts and increased the removal rate of binder during solvent extraction process. However, it seemed that increasing the SA had a little negative effect on the as-moulded density.

Metal Injection Moulding of Hip Stem CoCrMo Alloy Powder Using Palm Stearin Binder System

2016 ◽  
Vol 1133 ◽  
pp. 334-338
Author(s):  
Mohd Afian Omar ◽  
Noorsyakirah Abdullah ◽  
Rosliza Sauti ◽  
Nurazilah Mohd Zainon ◽  
Nurhaslina Johari ◽  
...  
Keyword(s):  
Stearic Acid ◽  
Injection Moulding ◽  
Alloy Powder ◽  
Palm Stearin ◽  
Complete Removal ◽  
Paraffin Wax ◽  
Binder System ◽  
Time Duration ◽  
Cocrmo Alloy ◽  
Metal Injection Moulding

Metal Injection Moulding (MIM) has undergone development of various binder systems with the aims of shortening the overall debinding time duration. In the present work, binder system based on biopolymer has been utilised in injection moulding of hip stem CoCrMo alloy powder. The feedstock consisted of CoCrMo powder with mean diameter particle size of 16μm and binder system which comprised of major fraction of wax and minor fraction of polyethylene. The moulded part was immersed into n-heptane at 60°C in order to remove the paraffin wax and stearic acid, followed by sintering in a controlled vacuum atmosphere. Results showed that solvent extraction debinding technique allowed complete removal of paraffin wax and stearic acid from the injection moulded part within 5 hours without swelling or distortion of the debound part. Lower heating rate needed during thermal pyrolysis in order to retain the shape due to the thickness of the part.Keywords: CoCrMo, MIM, wax, debinding,

Study of a Binder System for Ti-MIM: A Potential Low Temperature Backbone Polymer

2018 ◽  
Vol 770 ◽  
pp. 206-213 ◽  
Author(s):  
Hong Zhou Zhang ◽  
Muhammad Dilawer Hayat ◽  
Xuan Hui Qu ◽  
Pratik Prakash Jadhav ◽  
Xin Gang Wang ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Low Temperature ◽  
Stearic Acid ◽  
Rheological Properties ◽  
Injection Moulding ◽  
Polyvinyl Acetate ◽  
Water Soluble ◽  
Titanium Metal ◽  
Binder System ◽  
Impurity Control

Impurity control remains to be a challenge to titanium metal injection moulding (Ti-MIM). Much attention has been paid to polyethylene glycol (PEG) based binder systems due to the eco-friendly and water-soluble feature of PEG. In this study, a new easy-to-debind PEG/polypropylene carbonate (PPC)-based binder system (76% PEG+17% PPC+3% polymethyl methacrylate (PMMA)+2% stearic acid (SA)+2% polyvinyl acetate (PVAc)) was developed. The rheological properties of the feedstocks prepared with the binder system in different proportions were assessed. Debinding behaviours of the moulded samples and impurity contents of oxygen (O), carbon (C), and nitrogen (N) of the thermal debound specimens were investigated as well.

scholarly journals Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Service Life ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

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.

Porous NiTi alloy by metal injection moulding/sintering of elemental powders: Effect of sintering temperature

2012 ◽  
Vol 70 ◽  
pp. 142-145 ◽  
Author(s):  
Muhammad Hussain Ismail ◽  
Russell Goodall ◽  
Hywel A. Davies ◽  
Iain Todd
Keyword(s):  
Injection Moulding ◽  
Sintering Temperature ◽  
Niti Alloy ◽  
Porous Niti ◽  
Metal Injection Moulding
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