Characterisation and properties of hybrid coatings deposited onto magnesium alloys

Abstract

This paper presents the research results of the physical vapour deposition and chemical vapour deposition surface treatment performed on samples of heat treated cast magnesium alloy as well as the modelling of properties of the obtained coatings using the finite element method. Ti/Ti(C, N)/CrN, Ti/Ti(C, N)/(Ti, Al)N, Ti/(Ti, Si)N/(Ti, Si)N, Cr/CrN/CrN, Cr/CrN/TiN and Ti/DLC/DLC coatings were investigated. Based on fractographic investigations, it was found out that the applied coatings are characteristic of mono-, di- or multilayer structure according to the applied layer system. The individual layers are deposited uniformly and adhere tightly to the substrate and to each other. The coatings reveal a dense cross-sectional morphology as well as good adhesion to the substrate. The critical load L_C2 was measured within the range of 11–19 N, depending on the coating type. The results obtained from numerical analysis performed using a mathematical model have enabled full integration of material engineering knowledge and informatics tools.

Keywords:

• Magnesium alloys
• Residual stress
• PVD
• CVD
• Structure
• Properties