The Influence of Sintering Atmosphere for Metal Injection Moulding M2 High Speed Steel

2014 ◽  
Vol 879 ◽  
pp. 169-174
Author(s):  
R. Sauti ◽  
N.A. Wahab ◽  
M.A. Omar ◽  
I.N. Ahmad

This paper reports on the compatibility of waste rubber as binder for M2 High Speed Steel injection moulding. The feedstock was prepared at a powder loading of 65 vol.% using 22μm M2 High Speed Steel powder and the binders consisting of 55wt.% paraffin wax, 21wt.% polyethylene, 14wt.% waste rubber and 10wt.% stearic acid. The specimens were then sintered in vacuum and 95%N2/5%H2 atmosphere. The sintering in vacuum atmosphere occurred within a temperature range from1200°C to 1260°C, whilst the 95%N2/5%H2 atmosphere was carried out within a temperature range from 1220°C to 1300°C. The effects of the sintering atmosphere and temperature on the physical properties, mechanical properties and microstructure were investigated.

2014 ◽  
Vol 1024 ◽  
pp. 201-204 ◽  
Author(s):  
Rosliza Sauti ◽  
Nor‘aini Wahab ◽  
Mohd Afian Omar ◽  
I.N. Ahmad

This paper reports on the compatibility of waste rubber binder combined with conventional binder, paraffin wax and local binder, palm stearin for M2 High Speed Steel injection molding in order to obtain the better properties. The feedstock was prepared at a powder loading of 65 vol.% using 22um M2 High Speed Steel powder and the binders consisting of 55wt.% paraffin wax/palm stearin, 21wt.% polyethylene, 14wt.% waste rubber and 10wt.% stearic acid. The specimens were then sintered in vacuum atmosphere within a temperature range from 1200°C to 1260°C. The results shown even the best properties is obtain from the conventional binders, paraffin wax, thus the properties of local binders palm stearin is still comparable and good. The maximum density of paraffin wax binder was 8.095g/cm3 achieved at temperature 1250°C and palm stearin binder was 8.111g/cm3 achieved at temperature 1240°C. Therefore, in term the best strength of paraffin wax was 2351Mpa whilst palm stearin was 2210MPa, both recorded at temperature 1230°C.


2014 ◽  
Vol 879 ◽  
pp. 112-118 ◽  
Author(s):  
Noraini Abd Wahab ◽  
Mohd Afian Omar ◽  
Rosliza Sauti ◽  
Nor Amalina Nordin ◽  
Ismail Nasiruddin Ahmad

Tendency of injection moulded parts to necessitate a long debinding time which consequently leads to an increase of defects formation has been a major obstacle for the economic process of Metal Injection Moulding (MIM). In the present study, a novel binder system based on waste rubber has been formulated in injection moulding of Molybdenum High Speed Steel (M2 HSS). The feedstock consisted of M2 HSS powder with mean diameter particle size of 16μm and binder which comprised of palm stearin, polyethylene, waste rubber and stearic acid. The moulded part was immersed into n-heptane at 60°C in order to remove the palm stearin and stearic acid, followed by sintering in a controlled vacuum atmosphere. Results showed that solvent extraction debinding technique allowed complete removal of palm stearin and stearic acid from the injection moulded part within 3 hours without swelling or distortion of the debound part. In addition, this study has demonstrated that, the novel binder system has successfully shorten the debinding time through a single stage debinding process whilst the sintered part possessed approximate density of 8.1 g/cm3 and hardness of 76.9 HRC.


2012 ◽  
Author(s):  
Mohd. Asri Selamat ◽  
Mazlan Mohamad

Keupayaan untuk menghasilkan keluli laju–tinggi kepada bentuk hampir sebenar menggunakan relau tali–sawat berterusan menawarkan peluang untuk mempertingkatkan sifat–sifat serta mengurangkan kos pemprosesan bahan keluli ini. Sehingga kini, masalah yang timbul bagi mencapai matlamat tersebut adalah keperluan menggunakan suhu persinteran tinggi (1250–1350°C) di dalam atmosfera vakum. Satu kaedah persinteran yang murah terhadap serbuk keluli laju–tinggi pengabusan–air telah dibangunkan menerusi projek ini menggunakan mekanisme Persinteran Fasa Pepejalan–lampau Cecair (PFPC). Serbuk M3/2 keluli laju–tinggi ini boleh tersinter kepada ketumpatan penuh (>95% daripada ketumpatan teori) di dalam atmosfera berasaskan–nitrogen pada suhu persinteran 1150°C. Mikrostruktur dan sifat–sifat mekanik yang baik telah berjaya dihasilkan selepas proses rawatan haba yang sesuai dilakukan. Kata kunci: Pepejalan-lampau, serbuk pengabusan-air, atmosfera berasaskan-nitrogen The ability to produce near net shape high–speed steels using a continuous belt furnace offers the opportunity to improve the properties and reduce the processing cost of these materials. So far, the difficulty in making this advancement has been the requirement of high sintering temperatures (1250–1350°C) in vacuum atmosphere. A low cost–sintering route of water–atomised high–speed steel powder has been developed during this project using Supersolidus Liquid Phase Sintering (SLPS) mechanism. This water–atomised M3/2 high–speed steel powder can be sintered to full density (>95% of theoretical density) under nitrogen–based atmosphere at sintering temperature of 1150°C. Acceptable microstructures and mechanical properties have been obtained after appropriate heat treatment. Key words: Supersolidus, water-atomised powder, nitrogen-based atmosphere


2013 ◽  
Vol 845 ◽  
pp. 939-944
Author(s):  
Noraini Abd Wahab ◽  
Mohd Afian Omar ◽  
Nor Amalina Nordin ◽  
Rosliza Sauti ◽  
M.D. Kamal Bahrin

New feedstock formulation for metal injection moulding (MIM) of Molybdenum High Speed Steel (M2 HSS) has been developed. The binder is a multicomponent system consisting of major binder paraffin wax (PW), stearic acid (SA) and minor binder polyethelene waste rubber (PEWR). Injection moulding was conducted successfully using a powder loading of 0.65. Scanning electron micrograph of the green injection moulded part revealed homogenous distribution of the M2 HSS particles in the wax matrix. Paraffin wax and stearic acid were driven off by immersing the injection moulded part into n-heptane for five hours. Vacuum sintering of the brown parts at a temperature range of 1240°C-1280°C resulted in high quality M2 HSS parts. The properties of the sintered part such as physical, mechanical and microstructure were studied and discussed to evaluate the influence of waste rubber in MIM of M2 HSS.


2003 ◽  
Vol 437-438 ◽  
pp. 137-140
Author(s):  
Q.J. Hu ◽  
C.M. Choy ◽  
Z.D. Chen ◽  
Jerry Y.H. Fuh ◽  
Yoke San Wong ◽  
...  

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