Mechanically deposited Zr55Cu30Al10Ni5 coatings

• Grant number: 20/01653-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2021
• End date: June 30, 2022
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Guilherme Yuuki Koga
• Grantee: Pietro Cazelatto Bortolini
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Metallic glasses exhibit high mechanical resistance due to the absence of plastic deformation by dislocation movement, since they are characterized by the lack of long-range ordering. Among the metallic glasses that display high glass forming ability (GFA), the Zr-base alloys are interesting because of the large critical thickness of the vitreous formation. However, these alloys are produced generally by non-conventional casting routes such as melt-spinning and copper-mold suction casting. The resulting alloys are, therefore, characterize by a reduced size (ribbons or small ingots) that inhibits their industrial use as structural components. Most of the engineering metallic equipment’s is made with steel because of the practical and economical reasons. The service-life os such components can be extended by the use of coatings produced by advanced alloys. Surface engineering thus enables the protection of steel structures, which present satisfactory structural properties at low-cost, by coatings of nobler alloys such as Zr-based metallic glass that confer high hardness and wear resistance at the surface. In this project, metallic Zr55Cu30Al10Ni5 %at. glass will be produced by melt-spinning, and characterized by x-ray diffraction and differential scanning calorimetry. These ribbons will be cut in small segments and inserted with hard-chromin spheres (8 and 5 mm diameter), in a mass fraction of 1 : 30, into a vial. A mild steel target will be placed at the lid of the vial. The vial will be hermetically closed and some valves of the system allow to control the atmosphere, which will be argon to avoid oxidation. Mechanical deposition will be performed for 8 h using a Spex mill. The deposited coating will be characterized by x-ray diffraction and scanning-electron microscopy. Vickers micro hardness measurements will be carried out as complement. The results of this project are aimed for the understanding whether metallic Zr55Cu30Al10Ni5 %at. glass alloy can be used as coating produced by mechanical deposition. (AU)