The need behind the science.. Or how a shortage causes an invention. Everything started in east Europe in the late 50s...
Picture: Europe in the late 50s during the cold war.
After World War II some east European countries were facing severe problems to buy Cr and shortage Ni on the free market to cover their needs for stainless steel production and materials for high temperature using. To overcome this shortage Russia and Czech Republic initiated a strong partnership in the 50s between national research institutions, universities and local industry to develop low cost alternatives for heat resistant cast iron and stainless steel alloys based on intermetallics casted from accessible and cheap Iron, Aluminium and Carbon. These efforts result in the past in the materials such as Thermagal© Tchugal© and Pyroferal©. Pyroferal© offered quite impressive results on high temperature corrosion resistance. It was tested against various severe conditions, such as air atmosphere, vanadium pentoxide, molten glass, carburization, nitration and the atmosphere of the natural gas cracking generators. Though Pyroferal© was manufactured only by casting, welding was the important procedure not only to produce complicated shapes, but also to repair the faults in casts. Unfortunately, the practical use of these materials was limited due to various problems. These problems related to instability and welding could not be overcome by state of the art in material science at that time. In the 60s, access to Chromium was no problem any longer and the dust of history covered the knowhow on (pre-) industrial use of FeAl. But things may change again. Chromium and Nickel are listed in the table of CRMs with a current projected lifetime of 25 - 100 years.
EQUINOX tries to blow away the dust of history from this early work on FeAl, aiming to combine latest state of the art in intermetallic metallurgy to overcome the problems that our ancestors were facing when they failed to translate unique corrosion and wear properties of FeAl into a low cost Cr/Ni-free alternative for stainless steel products.
There is a need to find solutions to replace Critical Raw Materials (CRMs) such as Chromium, Nickel, Molybdenium and Vanadium in high volume end consumer products. Steels and superalloys with considerable amounts of these CRMs are widely used in many industrial applications, particularly under extreme conditions where corrosion and wear resistance are needed. It is generally accepted, that intermetallics in particular low cost FeAl offer outstanding material properties. Unfortunately it is difficult to translate their properties to real products, as intermetallics suffer from low ductility at ambient temperature and poor machinability. The impact of FeAl intermetallics as a low cost Cr-free alternative for stainless steel would therefore be much higher if a cost effective industrial process would be available, that allows to manufacture complex 3-D geometries of almost unlimited shapes from small grain size (0.1-5 µm) high ductility material.
The main objective of EQUINOX is to develop a novel process that allows to substitute Cr/Ni based (stainless) steel parts used in high volume end consumer products such as in the lock industry, electronics, process industry and automotive industry with a novel near net shape production technology for a new class of highly advanced ductile Fe-Al based intermetallics. Ductility at low to medium temperatures, while maintaining good tensile strength and optimum level of residual stress will be based on a radical new production process that use abundant raw material Fe3O4 and Al2O3.
A novel near net shape production technology that allows to substitute stainless steel parts in high volume end consumer markets by a new class of CRM-free, ductile Fe-Al based intermetallics.
To produce extremely fine grained FeAl-Material with high ductility via reactive infiltration of porous iron preforms with liquid Aluminium. To understand how ultrafine particle based porous iron structures of complex 3D-shape may be tailored to be used as optimized preforms for reactive infiltration of liquid Al-alloys. To develop a reactive infiltration process by usingtwo different techniques: suction and centrifugal casting. To simulate reactive infiltration process by physically based multi-scale models based on StarCast and MICRESS. To optimize mechanical properties of EQUINOX material with respect to microstructure based on process conditions and consecutive heat treatment. To scale up the process from lab to small pilot plant with respect to the industrial needs. To transfer the concept to at least one real demonstrator which will be tested for high corrosion and wear resistance. To evaluate the industrial impact of EQUINOX-concept with respect to economic as well as technical aspects.
The EQUINOX process well fits into “Growing a Low Carbon, Resource Efficient Economy (1) with a Sustainable Supply of Raw Materials (2) - for materials under severe conditions (3)” by many aspects:
No CO2 is produced as side product as oxygen from raw material iron-oxide is fixed as H2O. No waste of material: 100 % of the material that enters into the process chain ends up as final product of complex 3 D-shape. No energy is used for “material tourism” All steps of the process run at one single location –Fe3O4 and Al entering through the front door and final 3D-shaped Intermetallic parts leaving through the back door. Solar heat may be used to cover most part of energy input as temperature level is just slightly above the melting point of Al in all steps involved. The process may be completely based on H2(which could be made from renewable energy). Materials with properties close to stainless steel are manufactured from abundant Fe and Al -without (or at least drastically reduced)CRM-materials Cr/Ni/Mo. EQUINOX materials exhibit properties that withstand corrosion, cavitation and wear offering good results on LCA (life cycle analysis).
It is obvious that the impact of FeAl as a low cost Cr-free alternative for stainless steel would be much higher if a cost effective process would be available, one that allows to manufacture complex 3-D geometries of almost unlimited shapes from small grain size material at high volumes. Today this process is obviously missing as outlined earlier. For this reason EQUINOX has invited some of the most advanced groups on intermetallics from Spain, Germany and Czech Republic under the external advisory of Max-Planck-Institut für Eisenforschung GmbH which has an outstanding tradition of more than 40 years in that field. EQUINOX will combine the sound expertise of these R&D-partners with the market push of outstanding industrial players in the field of process technology. Following this, EQUINOX addresses a special sector of a huge market in the first run, the impact of which will be multiplied by entering other sectors through a sound D&E-strategy in a later stage.
This is what EQUINOX is Aiming for: A radical new process for low cost manufacturing of complex shaped intermetallic FeAl parts with corrosion and wear resistance equal to INOX® - with a raw material that is either completely free of CRM or incorporating these elements in very small amounts - just to tailor the grain surface at the atomic level.
Equinox project Kick-Off meeting. National Technical University of Athens, Greece.Tuesday, 16/2/2016.
Picture: Equinox partners during kick off meeting of project.