Technical papers in the current issue...

Listed below are the abstracts from technical papers published in the current issue of Powder Injection Moulding International (Vol.3 No.1). If you would like to submit a paper for consideration please email Paul Whittaker

The full papers can be found in the listed volume/number of Powder Injection Moulding International. PDF's of all articles and papers from each issue of PIM International can be purchased from the PIM International PDF Store three months after the date of publication.

Sintered Ba hexaferrite shaped by powder injection moulding in a DC magnetic field
B. S. Zlatkov(1), M. V. Nikolic(2), H. Danninger(3), O. Aleksic (2)

(1) FOTEC Forschungs- und Technologietransfer GmbH, Viktor Kaplan-Strasse 2, 2700 Wiener Neustadt, Austria
(2)Institute for Multidisciplinary Research, Kneza Viseslava 1, 11000 Beograd, Serbia
(3) Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164, 1060 Wien, Austria

Ba - hexaferrite specimens with an oriented structure were produced by the powder injection moulding technology (PIM). Ferrite powder (BaFe12O19) with an average particle size of 0.4 µm was mixed with a low viscosity binder (wax, thermo-plastics, solvents and additives) to form a feedstock to be used in the PIM process. The feedstock was injected into a cylindrical mould by an injection moulding machine. The influence of the injection parameters such as feedstock temperature and pressure on final magnetic properties was analysed. A solenoid with a high DC current was positioned around the cylindrical mould to orient single domain particles and clusters in the cylinder main axis direction. The optimal magnetic field intensity was determined that is needed for efficient magnetic orientation of single domain particles and clusters in the heated feedstock during the PIM process. Both isotropic (non-oriented) and anisotropic (oriented) green samples were produced. The green samples were then solvent debinded in acetone and dried slightly above room temperature. The remaining binder was then combusted in air during the sintering process. The sintering procedure was optimised in order to attain a maximum energy product value - (B×H)max in two steps: optimization of the sintering temperature and optimization of the sintering time. Magnetic properties of the green and sintered samples were measured parallel to the specimen axis using a hysteresis-graph. It showed that sintering for 2 h at 1200°C resulted in optimum magnetic properties, which are well comparable to those of ferrites produced by conventional routes.

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Co-sintering of functionally graded Fe2Ni/Fe2NixCr composites
Hao He, Yimin Li, Jia Lou, Jianguang Zhang

State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, China

In this work, the co-sintering compatibility between Fe2Ni and Fe2Ni with different amounts of Cr additions (Fe2NixCr, x=0.5, 1, 3) was studied. The intent is to manufacture functionally graded composites for applications that require a combination of toughness and wear resistance. The densification, bond strength and microstructure of the composites were examined. It was found that the density and bond strength of the composites increase at first, and then decrease with increasing chromium content. Co-sintering significantly aids the densification of the Fe2NixCr side. The density of the composites is not uniform but graded from the Fe2Ni side to Fe2NixCr side. In all cases the interface is free of cracks. A transitional zone composed of granular pearlite and lamellar pearlite was clearly seen. The best results were found using Fe2Ni/Fe2Ni1Cr composition. Final parts had densities close to 96% and a bond strength of 289.9 Mpa.

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Advanced metal powder injection moulding for multilayered micro porous titanium components
Kazuaki Nishiyabu(1), Satoru Matsuzaki(2), Shigeo Tanaka(2)

(1) Osaka Prefectural College of Technology, 26-12 Saiwai, Neyagawa 572-8572, Osaka, Japan
(2) Taisei-Kogyo Co., Ltd., 26-1 Ikeda-kita, Neyagawa 572-0073, Osaka, Japan

Metal powder injection moulding (MIM) is a promising net-shape manufacturing method for porous metal components with high dimensional accuracy and 3 dimensional complicated shapes, which are required in several highly functional applications. Powder space holder (PSH) method is capable of fabricating the controlled pore structures the pore size and can be changed from sub-microns to a few hundred microns, and porosity from 0% to around 80% in volume. In this study, pure titanium was chose for experiments as the representative materials of medical implants. The aim of this study is to demonstrate the feasibility and effectiveness of MIM process in producing the multilayered porous metal components. The thick-walled cylindrical pipe structures with three layers of various porosities were moulded by sequential injection moulding, and sintered by co-bonding. The pore formation and some physical properties of sintered porous specimens produced using porous compounds with various fractions of space holding particle were investigated. It was confirmed that the method proposed in this study was useful in producing the metal components with micro-sized pores and multi-layered structures.

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Past Papers

For full abstracts of past papers click through to the relevant page.

Powder Injection Moulding International Vol 2, No 4

Powder Injection Moulding International Vol 2, No 3

Powder Injection Moulding International Vol 2, No 2

Powder Injection Moulding International Vol 2, No 1

Powder Injection Moulding International Vol 1, No 4

Powder Injection Moulding International Vol 1, No 3

Powder Injection Moulding International Vol 1, No 2

Powder Injection Moulding International Vol 1, No 1

Submitting technical papers to PIM International
Each issue of PIM International is circulated to 3000 contacts worldwide involved in powder injection moulding production and research. We are currently publishing three technical papers in each issue and would be very pleased to hear from you if you are interested in publishing a technical paper with us. Please contact Paul Whittaker, tel: +44 (0)1743 241289, e-mail: paul@inovar-communications.com for further information.