Villapún Victor M, Esat F, Bull S, Dover L G, González S
Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, UK.
School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK.
Materials (Basel). 2017 May 6;10(5):506. doi: 10.3390/ma10050506.
The influence of cooling rate on the wear and antimicrobial performance of a CuZAl₇ (at. %) bulk metallic glass (BMG) composite was studied and the results compared to those of the annealed sample (850 °C for 48 h) and to pure copper. The aim of this basic research is to explore the potential use of the material in preventing the spread of infections. The cooling rate is controlled by changing the mould diameter (2 mm and 3 mm) upon suction casting and controlling the mould temperature (chiller on and off). For the highest cooling rate conditions CuZr is formed but CuZr₂ starts to crystallise as the cooling rate decreases, resulting in an increase in the wear resistance and brittleness, as measured by scratch tests. A decrease in the cooling rate also increases the antimicrobial performance, as shown by different methodologies (European, American and Japanese standards). Annealing leads to the formation of new intermetallic phases (CuZr₇ and Cu₂ZrAl) resulting in maximum scratch hardness and antimicrobial performance. However, the annealed sample corrodes during the antimicrobial tests (within 1 h of contact with broth). The antibacterial activity of copper was proved to be higher than that of any of the other materials tested but it exhibits very poor wear properties. Cu-rich BMG composites with optimised microstructure would be preferable for some applications where the durability requirements are higher than the antimicrobial needs.
研究了冷却速率对CuZAl₇（原子百分比）块体金属玻璃（BMG）复合材料磨损和抗菌性能的影响，并将结果与退火样品（850℃，48小时）和纯铜的结果进行了比较。这项基础研究的目的是探索该材料在预防感染传播方面的潜在用途。通过在吸铸时改变模具直径（2毫米和3毫米）并控制模具温度（冷却器开启和关闭）来控制冷却速率。在最高冷却速率条件下会形成CuZr，但随着冷却速率降低，CuZr₂开始结晶，通过划痕试验测量，这导致耐磨性和脆性增加。如不同方法（欧洲、美国和日本标准）所示，冷却速率的降低也会提高抗菌性能。退火导致形成新的金属间相（CuZr₇和Cu₂ZrAl），从而产生最大的划痕硬度和抗菌性能。然而，退火样品在抗菌测试期间（与肉汤接触1小时内）会发生腐蚀。已证明铜的抗菌活性高于任何其他测试材料，但它的磨损性能很差。对于某些耐久性要求高于抗菌需求的应用，具有优化微观结构的富铜BMG复合材料可能更合适。
