Wednesday morning, 13 October

Chairmen:
Mr Marko Maetzig, Arburg GmbH
Professor Jean Claude Gelin, FEMTO_ST Institute

Oral

Effect of Delay Time on Material Distribution of Metal Co-injection Moulding
Li, Y (Central South University, Changsha, China)

The present study addresses an experimental study of co-injection molding which involves sequential injection of dissimilar metal feedstocks. The effect of delay time between the first and second injection processes on the material distribution of co-injection molded plates has been studied. It was demonstrated that the penetration depth of the core material increases with the increase of delay time. The experimental results were analyzed by taking account of the relative viscosity of the two melts. The increase of delay time decreases the temperature of the skin material and hence increases its viscosity, resulted in lower velocity during mold filling. The relationship between delay time and temperature, as well as temperature and viscosity was established using unsteady heat conduction model and Arrhenius equation. The result indicates that the differences in rheological properties of the metal feedstocks involved are the primary variable determining the phase distribution of the molded parts.

IKTS Activities In Two-Component Powder Injection Moulding
Moritz, T (Fraunhofer IKTS, Bremen, Germany)

The presentation introduces the research and development results of Fraunhofer IKTS in the field of two-component powder injection moulding of multifunctional ceramic components and ceramic/metal material composites. Challenges and chances of this high-throughput shaping technique will be shown and examples from the automotive sector will be demonstrated. It will be outlined which requirements have to be met by the materials choice and by the feedstock combination for two-component powder injection moulding. Non-destructive testing methods will be shown to be a very helpful tool for characterizing the components and for detecting defects caused by the injection moulding already before time-consuming thermal treatment steps.

Influence of a Mismatch in Shrinkage for Two-Component Metal Injection Moulding (2C-MIM)
Mulser, M (Fraunhofer IFAM, Bremen, Germany)

Two-Component Metal Injection Moulding is a manufacturing process in powder technology which enables the production of multifunctional parts without additional assembling. Compatible feedstocks which must be adjusted in shrinkage are required to assure adequate co-debinding and co-sintering.

In this study, dilatometry measurements for the stainless steels 430 and 314 were performed. A variation of the particle size was carried out to adjust the characteristic sintering parameters, i.e. the beginning of shrinkage, the maximum shrinkage and the thermal expansion. Feedstocks, which showed only a slight difference in parameters, were combined systematically to study the effect of typical mismatches in shrinkage on the quality of the interface.

The steels 430 and 314 were chosen to produce a magnetic-nonmagnetic connection. Micro tensile tests, as well as hardness and EDX measurements were performed, to verify a crack-free, well connected interface with adequate mechanical strength and a sharp interdiffusion zone at the magnetic-nonmagnetic interface.

Progress of two-component micro powder injection moulding (2C-MicroPIM)
Ruh, A (Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)

Two-component micro powder injection moulding (2C-MicroPIM) provides some very interesting opportunities to microsystem technology. It allows the combination of different features like hard - soft, magnetic - non-magnetic, electrically conductive - insulating as well as hard - tough by integrating different materials within one micro device. However, it is accompanied by complex challenges. In the presented study the availability of 2C-MicroPIM for the production of fixed as well as movable shaft-to-collar connections will be discussed. In detail, the influence of the materials like ceramic powders and binder components, the design of the injection moulding tool and the adjustment of the process parameters are important steps, which have to be understood and optimized. With respect to this task significant progress compared to previous trials has been achieved. The influences of these factors are presented as well as essential methods for improving 2C-MicroPIM for the production of movable and fixed connections.

Poster

Sintering of WC-10Co/316L Stainless-Steel Composite Parts Made by Assembling of the PIM Parts
Simchi, A (Sharif University of Technology, Tehran, Iran)

This paper reports co-sintering response of WC-Co/316L stainless steel composite produced by assembling of powder injection molding (PIM) parts. A significant mismatch sintering shrinkage (>4%) was observed in the temperature range of 1080-1350 °C. The reaction between WC and Fe at the contact area also resulted in the diffusion of C and Co into the iron lattice and eventually formation of a low-temperature liquid phase that in fact affects the shape control of the PIM parts during sintering. In order to make the co-sintering feasible, a special sintering cycle was developed. The reaction between the cemented carbide and stainless steel was also retarded by developing a special Ni-W past. This articles presents a protocol to fabricate WC/316L composite structures by powder injection molding process. Such a composite structure is practically very useful because only a part of the article is made from cemented carbides to yield wear resistance while the rest is manufactured from a cheaper metal with an aim of cost reduction and/or to provide a function, for example, corrosion resistance.

Opportunities and possibilities through PIM
Walcher, H (ARBURG GmbH + Co KG, Lossburg, Germany)

Powder Injection Moulding nowadays is a mature technology for the production of complex shaped parts for almost all industrial areas including automotive, medical, mechanical, consumer and information technologies.

This presentation will give an overview on different technological aspects for the production of complex shaped PIM parts and addresses how to achieve them. These technologies include the use of lost core or multi component processes as well as gas assisted moulding and coining options.

Related features for download:

• Co-sintering of functionally graded Fe2Ni/Fe2NixCr composites
• Al/SiC composites with high reinforcement content prepared by PIM/pressure infiltration
• Powder injection moulding of cemented carbides (Hardmetals): a global industry with a bright future
• Developments in tungsten carbide-cobalt cemented carbides