Novel Cu-Zr-Al metallic glass composites with optimum antimicrobial and wear performance

Novel metallic glass composites with optimum antimicrobial and wear performance

Victor M. Villapún1, H. Zhang2, L. Cheung Chow3, C. Howden3, F. Esat4, P. Pérez5, J. Sort6, S. Bull7, J. Stach3, S. González1a*
1*Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, UK, sergio.sanchez@northumbria.ac.uk
2Departament de Física, Facultat de Ciències, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
3Newcastle University, School of Biology, Newcastle upon Tyne NE1 7RU, UK
4Institute for Materials Research. University of Leeds, Leeds, LS2 9JT, UK
5Centro Nacional de Investigaciones Metalúrgicas, CSIC, Avda. Gregorio del Amo 8, 28040 Madrid, Spain
6Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010 Barcelona,Spain
7Newcastle University, School of Chemical Engineering and Advanced Materials, Newcastle upon Tyne NE1 7RU, UK


Antimicrobial copper is the most effective touch surface material against pathogenic microbes since it can kill more than 99.9 % bacteria within 2 hours of exposure. However, copper is a relative soft material that exhibits low wear resistance compared to other materials. An easy technique to improve the durability of the material is to mix copper with other elements and cool fast enough to form metallic glass composites, although it might be at the expense of losing part of the antimicrobial ability. The aim of this work is to study the antimicrobial and wear performance of alloys corresponding to the CuZrAl system with increasing content of Cu (50, 53 and 56 at. %). The wear resistance of the samples was observed to increase with increasing addition of Cu due to the formation of small intermetallic phases embedded in an amorphous matrix.
Antimicrobial tests with E. coli (gram-negative) or B. subtilis (gram-positive) cells for the x=50 specimen did not display any antimicrobial properties when compared with plastic control after 4 hours contact. For the x=53 sample, E. coli and B. subtilis numbers were reduced by ca. 50% and 70% respectively. The x=56 sample reduced cell numbers by >99% for both species when compared to the plastic control. Time-kill studies relealed for x = 53 and 56 at. % Cu complete elimination of bacteria in 250 min but for x = 56 the reduction in colony-forming units after 60 min is higher than for x = 54.