MATERA SiNACERDI - Nanostructured composite materials and reinforced ductile iron for high wear applications
Project duration
2011 - 2014
Project Category
international
Contact Information
Partners
- ZORNIK d.o.o.(Slovenia)
- IceTec, FTJ (Iceland)
- SUT (Poland)
- CTP-GL (Luxemburg)
The project undertakes research on nanostructured hetero-modulus particulate composites (Si3N4, SiC-C, soft-matrix nanocomposite) and functional gradient materials (reinforced ductile iron) for a demanding application. The new developed products will show multiplied hardness and ten times higher wear resistance, coupled with stable and constant friction because of nanostructure benefits in particulate ceramic composites and functionalized surface of ductile iron. Developed products will be heavily tested for tribological applications, namely automotive brakes in the top-class cars and in face seals. The successful materials in the form of prototype will be evaluated in the field test. It is expected that the service life of the new components would be tripled.
Braking systems in transport vehicles such as motorcycles, cars, trucks, trains and airplanes must ensure the safety and reliability of any transport system. Therefore, the brake system must operate in all conditions equally reliable, with fixed friction properties and with a minimum wear rate of brake discs and pads. At the same time braking system shall be lightweight and low priced. From this perspective, ceramic braking system with brake discs of C-SiC composites on the surface and C/C composite base show tremendous advantage. At the same time problem of material brake pads remains completely unresolved. Problem is the extraction of the generated heat from the friction contact between the braking and the formation of thermal shocks due to high temperatures in contact and the consequent failure of classic pad. The same problem can be also traced in mechanical sliding seals, guides and other components operating in harsh conditions and require good flexibility of the entire contact during surface lifetime.
The project SiNACERDI we set the goal of the research, which will give us the answer how to build a high wear material, which will play in the toughest operating conditions, a stable and constant coefficient of friction and minimal wear. This objective will be tried to be achieve through research of nanoceramic and Al-base nanocomposite materials and solid silicon-based nanoparticles (Si3N4, SiC-C) and glass fibers and study the impact of micro-alloying on the tribological properties of ductile cast iron. The hypothesis is that we, through nano-and micro-alloying, will be able to develop materials with a structure that will enable low wear, good flexibility and a stable contact and constant coefficient of friction in the toughest operating conditions. The project proposal includes the mechanical activation of the ceramic powder, which causes deformation of the crystal structure of individual ceramic particles and at the same time "save" part of the energy in the form of various defects on the nanometer scale. Stored energy during the process of compaction reduces temperature of sintering certain mixtures or composites with covalent bonds (Si-O, Si-N, Si-C) would then retain the amorphous structure even at higher temperatures. Ductile cast iron contains graphite nodules that between tribological processes lubricate the surface and thus reduce friction coefficient in contact. The problem with this is poor wear resistance of ductile iron castings, uneven distribution of nodules can also lead to uneven contact and unstable friction coefficient. The micro-alloying of ductile iron overcome those deficiencies and thus improve its friction and wear properties. According to our forecasts micro-alloying would reach the same wear resistance as it has chemo thermal treated stainless steel but with much more stable friction coefficient. Micro-alloyed ductile iron will be also easily recyclable or reusable in the manufacture of new products, because it will contain an extremely small proportion of alloy elements.
The project will develop nano composite ceramics and optimize the technology of micro-alloying of ductile iron. We expect that the joint work of all partners in the research, processing, optimization and characterization will led to the development of a new material for automotive brake pair and mechanical seals with improved tribological properties and several times longer lifetime. The advantage of using ceramic materials in brakes and other components is also in the fact that current weight of brake or seal assembly decreased by several times. Work on the project will also expand our view of all partners in the field of nanomaterials in applications in power transmission and control technology. On the other it will also increase understanding and visibility of the partners in the project.