Canadian mineral development company Zenyatta Ventures Ltd says that several of its high purity graphite powders are now suitable for powder metallurgy (PM) applications.
Testing was conducted at the National Research Council (NRC) in Ottawa, Canada and was partially funded by a federal research grant through the National Research Council of Canada Industrial Research Assistance Program (NRC-IRAP). Zenyatta graphite samples were mixed with steel, copper and lubricant powders to produce a powder metallurgy specimen. The flow properties of the mixture compare favorably with the mixture made with benchmark materials in existing use. In addition, the mechanical properties of the final Zenyatta artifacts, after a sintering heat treatment, were comparable to those of the benchmark artifacts.
In particular, Zenyatta’s graphite showed the high purity and particle size specifications required for PM applications, especially when compared to reference graphite material.
Zenyatta expects to have a targeted market application segmentation which includes 25-30% for high purity graphite in PM, 25-30% in lithium-ion batteries and 20-25% for fuel cell products.
Market development
‘These latest screening tests conducted at NRC continue to show positive attributes of Zenyatta graphite in multiple applications,’ said Dr Bharat Chahar, VP of market development for Zenyatta. ‘It provides further evidence of the suitability of this unique material in many cleantech applications that we are targeting. The company will continue test programs at other labs and with global end-users but will involve larger scale test equipment to provide more extensive data to progress our market development plans.
‘Since the purity and particle size of the Zenyatta material provided was already in the range needed for PM application, no further milling or purification was needed,’ he added. ‘Due to simple mineralogy, high crystallinity and desirable particle size distribution, the Albany graphite has shown first testing specification ranges needed for the PM industry. While further tests will be conducted to verify other performance characteristics, this initial feedback on results is extremely encouraging.’
The PM market is estimated to be worth US$24 billion annually of which the graphite portion is estimated to be US$200 billion annually and growing at around 5% CAGR. Graphite is used in powdered metals as a source of carbon for the sintering process where it acts as a strengthening agent and as a lubricant. Graphite aids the release of PM parts from the die and is also used in conjunction with non-ferrous soft metals to provide self-lubrication (i.e. steel, brass and copper parts). The addition of graphite to ferrous parts, soft metals and ultra-hard alloys ranges from 0.2 to 3.5% of the total metal weight. Graphite is used because it is an excellent electrical and thermal conductor, it has outstanding lubrication properties and it is resistant to oxidation and cyclic temperature stress. It can withstand extreme temperatures while maintaining strength and shape. It is also inexpensive, light weight, easy to machine and replace compared to other materials.
This story is reprinted from material from Zenyatta, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
