Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran.
J Xray Sci Technol. 2018;26(3):509-521. doi: 10.3233/XST-17318.
The objective of this study is to investigate antibacterial characteristics of a thermal plasma spray system. For this purpose, copper powder was coated on a handmade atmospheric plasma spraying system made by the stainless steel 316 substrate, which is preheated at different temperatures before spraying. A number of deposition characteristics such as antibacterial characteristics, adhesion strength and hardness of coating, was investigated. All of the spray parameters are fixed except the substrate temperature. The chemical composition was analyzed by X-ray diffraction (XRD). A scanning electron microscopy (SEM) and back scattering electron microscopy (BSE) were used to show the coating microstructure, its thickness and also the powder micrograph. The energy dispersive X-ray spectroscopy (EDX) was used to analyze the coating particles. Hardness of the deposition was examined by Vickers tester (HV0.1). Its adhesion strength was declared by cross cut tester (TQC). In addition, the percentage of bactericidal coating was evidenced with Staphylococcus aurous and Escherichia coli bacteria. Study results show that as the substrates temperature increases, the number of splats in the shape of pancake increases, the greatness and percentage of the deposition porosity both decrease. The increment of the substrate temperature leads to more oxidation and makes thicker dendrites on the splat. The enhancement of the substrate temperature also enlarges thickness and efficiency of coating. The interesting results are that antibacterial properties of coatings against the Escherichia coli are more than Staphylococcus aurous bacteria. However the bactericidal percentage of the coatings against Staphylococcus aurous and Escherichia coli bacteria roughly does not change with increasing the substrate temperature. Furthermore, by increment of the substrate temperature, coatings with both high adhesion and hardness are obtained. Accordingly, the temperature of substrate can be an important parameter for progressing mechanical properties of the antiseptic deposition.
本研究的目的是探究热等离子喷涂系统的抗菌特性。为此，我们在手工制作的大气等离子喷涂系统上喷涂了铜粉，该系统的不锈钢 316 基底在喷涂前经过不同温度的预热。研究了多种沉积特性，如抗菌特性、涂层的附着力和硬度等。除了基底温度外，所有喷涂参数都保持不变。采用 X 射线衍射（XRD）分析了化学成分。扫描电子显微镜（SEM）和背散射电子显微镜（BSE）用于显示涂层的微观结构、厚度以及粉末形貌。能量色散 X 射线光谱仪（EDX）用于分析涂层颗粒。采用维氏硬度计（HV0.1）检测沉积层的硬度。采用十字切割测试仪（TQC）评估其附着力。此外，还通过金黄色葡萄球菌和大肠杆菌细菌来证明杀菌涂层的百分比。研究结果表明，随着基底温度的升高，类煎饼状的熔滴数量增加，沉积孔隙率的大小和百分比均降低。基底温度的升高会导致更多的氧化，并使熔滴上的树枝状晶体变厚。基底温度的升高还会增加涂层的厚度和效率。有趣的结果是，涂层对大肠杆菌的抗菌性能优于金黄色葡萄球菌。然而，涂层对金黄色葡萄球菌和大肠杆菌的杀菌百分比大致不会随基底温度的升高而变化。此外，通过增加基底温度，可以获得具有高附着力和硬度的涂层。因此，基底温度可以成为提高抗菌沉积机械性能的重要参数。
