The density is the most important feature in powder metallurgy. The higher the density, the better the properties, especially those of fatigue and impact because of their exponential dependency on density. There are three techniques in mass production to produce different density levels (in the order of increasing production costs): Single pressing and sintering technique (up to 7.2 g/cc ), double pressing and sintering (between 7.2 and 7.5 g/cc) and powder forging (between 7.5 and 7.85 g/cc). The most important need and issue in the powder metallurgical industry and consequently the required innovation is the production of high densities at acceptable costs: it would be a break through if the density level feasible by the double préssing and sintering technique can be produced at competitive costs by the warm powder compaction technology (7.2 to 7.5 g/cc) in the single pressing and sintering route. This would open a variety of new heavy duty applications in automotive and mechanical engineering and increase the volume of such parts which presently amounts to 25 % of the PM'business by at least 50 %.
The warmcompaction technology promises an economic way to realise parts with high densities around 7.4 g/cc, tensile strengths Rm = 900 to 1000 MPa and fatigue endurance limits oe = 350 to 450 MPa (depending on the post sintering heat treatment) which otherwise could be manufactured by the double pressing and sintering technique or powder forging if the latter two ways were not expensive. As the warm powder compaction is not yet established generally in production scale with the necessary reliability and economics for mass production, e.g. of fatigue and impact loaded automotive parts, particular efforts are necessary in order to install this technology and to gain a lead over oversea countries before they enter the European market. Industrial objectives in establishing the warm powder compaction technology are on one hand the entrance to new markets with competitive potential precision transmission parts like synchroniser hubs, rings, cones, sleeves (the latter two are new parts to be introduced) etc. in the density of 7.4 g/cc which so far have not been produced by ordinary PM' techniques because of economic reasons, and on the other hand the mastering of process stability from the standpoint of dimensional tolerances (IT 8).
Further, environmental objectives are given in this project by working out of green machining (dry drilling, tapping, turning) procedures, the recycling of rejected or scrap green parts before sintering and integrated heat treatments by rapid cooling in order to avoid conventional quenching baths.
The consortium comprises four PM'parts manufacturers as first users of the new technology to be established,
one powder producer,
one research institute on operational fatigue strength,
one materials science institute
and two automotive companies as end users from six countries.
Funding SchemeCSC - Cost-sharing contracts
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