Plastic Flow Under Shear-Compression at the Micron Scale-Application on Amorphous Silica at High Strain Rate

A new measurement technique based on microshear has been developed. This technique, inspired from a macroscopic test called the Shear Compression Specimen, was developed at the micron scale by making the specimen using FIB technology, and by compressing it using an in situ SEM nano-indenter. The experimental tests applied on the fused silica show a good repeatability of the data, at low and high strain rates (2000 s −1 ). Numerical simulation revealed that the deformation in the Microshear Compression Specimen is mainly shear. This approach allows a better understanding of surface shear properties at the micron scale, which is of primary importance for tribological surfaces. It can also help to better understand the surface mechanical properties of pressure dependent materials. Finally, since the shear is applied on a very small gauge in the specimen, it opens the way to very high strain rate experiments (10 4 s −1 strain rate).