Using an agar-based binder to produce porous NiTi alloys by metal injection moulding

2013 ◽  
Vol 37 ◽  
pp. 92-99 ◽  
Author(s):  
Gang Chen ◽  
Peng Cao ◽  
Guian Wen ◽  
Neil Edmonds ◽  
Yimin Li
Keyword(s):  
Injection Moulding ◽  
Niti Alloys ◽  
Porous Niti ◽  
Metal Injection Moulding

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

FEEDSTOCK FLOW CHARACTERIZATION AND PROCESSING OF POROUS NITI BY METAL INJECTION MOULDING (MIM)

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Muhammad Hussain Ismail ◽  
Nor Hafiez Mohamad Nor ◽  
Hywel A. Davies ◽  
Iain Todd
Keyword(s):  
Liquid Phase ◽  
Injection Moulding ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Optimum Operating ◽  
Vacuum Furnace ◽  
Major Fraction ◽  
Optimum Operating Condition ◽  
Porous Niti ◽  
Metal Injection Moulding

Porous NiTi alloy with a nearly three-dimensionally interconnected pore structure has been successfully fabricated by a transient liquid phase sintering following the metal injection moulding (MIM) process, using a mixture of Ni and Ti elemental powders. The elemental Ni and Ti powders mixture was mixed with a binder system, comprised mainly polyethylene-glycol (PEG) in an alternative technique using a speed mixer, principally incorporating a dual asymmetric centrifuge (DAC). The powder-binder mixture was then characterized using a capillary rheometer at various temperatures and shear rates. It was found that the feedstock exhibited pseudo-plastic behaviour, which is favourable for the MIM process. A temperature range of 120oC - 130oC was considered as the optimum operating condition for the injection moulding processing. The parts were moulded into cylindrical shapes, leached in warm water (60oC for 10 hours), thermally debound in argon and subsequently sintered in a vacuum furnace at four different temperatures ranging from 950oC to 1250oC.  All samples underwent expansion in both diameter and height after water leaching and sintering.  The XRD results showed that increasing the sintering temperature resulted in a major fraction of the B2 NiTi phase due to phase homogenization and subsequently decreased the amount of secondary phases such as NiTi2 and Ni3Ti. Besides that, the formation of the transient liquid phase during sintering enabled major fraction of pores to be developed with porosity and average size of 39 - 45% and 100 - 120 μm, respectively. The porous parts produced have a great potential to be used as an implant in biomedical applications. 

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.

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,

scholarly journals Injection moulding temperature and powder loading influence to the metal injection moulding (MIM) green compact

2011 ◽  
Vol 6 (21) ◽  
pp. 4532-4538 ◽  
Author(s):  
Rijal JAMALUDIN Khairur ◽  
MUHAMAD Norhamidi ◽  
AHMAD Sufizar ◽  
Halim Irwan IBRAHIM Mohd ◽  
Hafiez MOHD NOR Nor ◽  
...  
Keyword(s):  
Injection Moulding ◽  
Green Compact ◽  
Metal Injection Moulding
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