In situ SEM fracture test of micro cantilever beams in shale samples
1. Sample information Two shale samples are from the Yanchang Formation (representative terrestrial shale formation), Ordos Basin, and the Longmaxi Formation (representative marine shale formation), Sichuan Basin, respectively. 2. Test area description A total of six test areas are selected. Test areas in the terrestrial shale sample are named T1, T2, and T3 respectively. Test areas in the marine shale sample are named M1, M2, and M3, respectively. Each test area contains a organic matter particle, and the organic type of each particle is determined through geochemical analysis: (1) T1: Inertinite; (2) T2: Vitrinite; (3) T3: Vitrinite; (4) M1: Bitumen; (5) M2: Bitumen; (6) M3: Bitumen. Micro cantilever beams are fabricated in each test area by using Xe PFIB (Helios G4 PFIB, Thermo Fisher). Organic matter particle is placed at the fixed end of the cantilever beam. 3. In situ SEM fracture test Micro cantilever beams are loaded by an in situ mechanical test device (PI88, Hysitron) in an ESEM (Quanta 200F, FEI). A flat diamond indenter with a diameter of 10 μm is placed at the free end of micro cantilever beam. The loading rate is 15 nm/s. Side-by-side videos and load and displacement curves are provided.