Microstructure and Fracture Mechanism Investigation of Porous Silicon Nitride–Zirconia–Graphene Composite Using Multi-Scale and In-Situ Microscopy oleh Zhongquan Liao, Yvonne Standke, Jürgen Gluch, Katalin Balázsi, Onkar Pathak, Sören Höhn, Mathias Herrmann, Stephan Werner, Ján Dusza, Csaba Balázsi, Ehrenfried Zschech