Potential applications of cold sprayed Cu50Ti20Ni30 metallic glassy alloy powders for antibacterial protective coating in medical and food sectors

Abstract

Mechanical alloying was utilized for synthesizing of metallic glassy Cu50Ti20Ni30 alloy powders, using a low energy ball milling technique. The metallic glassy powders obtained after 100 h of ball milling had an average particle size of 1.7 mm in diameter and possessed excellent thermal stability, indexed by a relatively high glass transition temperature (358.3 oC) with a wide supercooled liquid region (61 oC). This amorphous phase crystallized into Ti2Cu and CuTiNi2 ordered phases through two overlapped crystallization temperatures at 419.3 oC and 447.5 oC, respectively. The total enthalpy change of crystallization was −4.8 kJ/mol. The glassy powders were employed as feedstock materials to double-face coating the surface of SUS 304 substrate, using cold spraying process under helium gas pressure at 400 oC. This coating material had an extraordinary high nanohardness value of 3.1 GPa. Moreover, it showed a high resistance to wear with a low value of the coefficient of friction ranging from 0.45 to 0.45. Biofilms were grown on 20-mm2 SUS304 sheets coated coupons inoculated with 1.5 × 108 CFU ml−1E. coli. Significant biofilm inhibition (p The inhibition of biofilm formation by nanocrystalline powders of Cu-based provides a practical approach to achieve the inhibition of biofilms formation.