Using In Situ TEM Helium Implantation and Annealing to Study Cavity Nucleation and Growth

Abstract

Noble gases are generated within solids in nuclear environments and coalesce to form gas stabilized voids or cavities. Ion implantation has become a prevalent technique for probing how gas accumulation affects microstructural and mechanical properties. Transmission electron microscopy (TEM) allows measurement of cavity density, size, and spatial distributions post-implantation. While post-implantation microstructural information is valuable for determining the physical origins of mechanical property degradation in these materials, dynamic microstructural changes can only be determined by in situ experimentation techniques. We present in situ TEM experiments performed on Pd, a model face-centered cubic metal that reveals real-time cavity evolution dynamics. Observations of cavity nucleation and evolution under extreme environments are discussed.

Study on upper and lower gas drainage and prevention and control technology in deep mine mining high gas mine

“…Coal seam strengthening is an effective way to improve gas drainage, and the key is to change the coal structure [9][10][11]. Protective layer mining technology can increase the micro cracks of coal body and release in-situ stress, so as to improve the permeability of coal seam, produce "pressure relief and flow increase effect" and realize effective gas drainage [12][13][14][15][16]. For outburst coal seam without protective layer, it can reduce the external stress of coal seam and change the physical and mechanical properties of coal, A variety of anti reflection technologies of the coal seam have been tested and applied, including large-diameter drilling, cross drilling and deep hole, dredging blasting, hydraulic anti reflection and gas explosion anti reflection.…”