Graphite can be added to alloys as a separate powder which is admixed with the metal powders used for PM structural parts

In its Spring 2017 issue, PM Review has published an in-depth report on graphite and its applications in the Powder Metallurgy industry. The report, by Dr Robert Feher, R&D Director at Graphit Kropfmuhl GmbH, Germany, looks at graphite’s use in composites, alloying elements and for special applications, and analyses the properties that make it viable for these purposes.

Graphite brush materials are composed of graphite bonded with resin or pitch to form a soft brush material

Graphite is chemically inert, eco-friendly and safe, states the report. It offers excellent electrical and thermal conductivity, lubrication properties, high temperature and oxidation resistance and the ability to form intercalation compounds. It can be employed as an alloying element, to increase the strength of sintered parts, as a second phase material in metal bonded particulate composites, for lubrication and friction moderation in bearings and for electrical applications such as switching devices for high voltages and currents.

The purification of graphite

Dr Feher’s report addresses the use of graphite in each of these applications in detail, looking at the engineering requirements of carbon brush materials, friction materials, self-lubricating bearings and specialised alloys – including metal compacts and sintered steel – and how the use of graphite can be optimised to suit them.

Featuring nine illustrative figures and drawing extensively on Dr Feher’s experience and study of Powder Metallurgy and metal properties, ‘Graphite and its applications in the Powder Metallurgy industry’ can be read for free in its digital edition, available to download from the PM Review website.