Partner: M.M. Natile


Recent publications
1.Alvi S., Jarząbek D.M., Kohan M.G., Hedman D., Jenczyk P., Natile M.M., Vomiero A., Akhtar F., Synthesis and mechanical characterization of a CuMoTaWV high-entropy film by magnetron sputtering, ACS Applied Materials and Interfaces, ISSN: 1944-8244, DOI: 10.1021/acsami.0c02156, Vol.12, No.18, pp.21070-21079, 2020
Abstract:

Development of high-entropy alloy (HEA) films is a promising and cost-effective way to incorporate these materials of superior properties in harsh environments. In this work, a refractory high-entropy alloy (RHEA) film of equimolar CuMoTaWV was deposited on silicon and 304 stainless-steel substrates using DC-magnetron sputtering. A sputtering target was developed by partial sintering of an equimolar powder mixture of Cu, Mo, Ta, W, and V using spark plasma sintering. The target was used to sputter a nanocrystalline RHEA film with a thickness of ~900 nm and an average grain size of 18 nm. X-ray diffraction of the film revealed a body-centered cubic solid solution with preferred orientation in the (110) directional plane. The nanocrystalline nature of the RHEA film resulted in a hardness of 19 ± 2.3 GPa and an elastic modulus of 259 ± 19.2 GPa. A high compressive strength of 10 ± 0.8 GPa was obtained in nanopillar compression due to solid solution hardening and grain boundary strengthening. The adhesion between the RHEA film and 304 stainless-steel substrates was increased on annealing. For the wear test against the E52100 alloy steel (Grade 25, 700-880 HV) at 1 N load, the RHEA film showed an average coefficient of friction (COF) and wear rate of 0.25 (RT) and 1.5 (300 °C), and 6.4 × 10^–6 mm^3/N m (RT) and 2.5 × 10^–5 mm^3/N m (300 °C), respectively. The COF was found to be 2 times lower at RT and wear rate 10^2 times lower at RT and 300 °C than those of 304 stainless steel. This study may lead to the processing of high-entropy alloy films for large-scale industrial applications.

Keywords:

high-entropy alloys, magnetron sputtering, spark plasma sintering, mechanical properties, wear

Affiliations:
Alvi S.-Luleå University of Technology (SE)
Jarząbek D.M.-IPPT PAN
Kohan M.G.-Luleå University of Technology (SE)
Hedman D.-Luleå University of Technology (SE)
Jenczyk P.-IPPT PAN
Natile M.M.-other affiliation
Vomiero A.-Luleå University of Technology (SE)
Akhtar F.-Luleå University of Technology (SE)