Microscale fracture of chromia scales

摘要: Native protective oxide scales offer resistance against corrosion for high temperature materials, which often work in extreme conditions of varying mechanical and thermal loads. The integrity such layers is critical importance, since their damage can lead to significant reduction material life. Mechanical data as fracture strain elastic modulus are required include oxides life estimation models but there lack data. Their thickness the mm range, makes testing property determination difficult. Here we present a micro-mechanical method, based on bending micro-cantilevers produced by focused ion beam milling, capable circumventing limitations conventional approaches. We apply this method chromia thermally grown pure chromium, measure strains at room temperatures (600 °C). measured were found be higher temperature, due larger fraction transgranular fracture. Surprisingly, large was seen even presence stress concentrations grain boundaries. Removal accentuated propensity cracking temperature. Realistic values obtained well. observed mixed trans- intergranular points towards need dedicated investigations both boundary strength cleavage single crystals order fully understand failure mechanisms scales.