Transmission electron microscope in-situ nano indentation method for micron alloy containing isometric single nano-twin crystal

Abstract

The invention provides a transmission electron microscope in-situ nano indentation method for micron alloy containing isometric single nano-twin crystal, and belongs to the field of transmission electron microscope in-situ mechanical testing f nano-twin crystal. A macro-micro-nano integrated diamond tool is used, each tip has a curvature radius of 40-90 nm and a height of 100-300 Mu m; the tips are arrayed and are distributed on the surface of the tool. The diamond tool is used to indent the surface of the alloy; the indented surface is processed by chemical mechanical polishing; the polishedalloy has surface roughness Ra of 0.5-0.9 nm. A scanning electron microscope with focusing ion beams is used to perform in-situ cutting, splicing, transporting and ion thinning, and a sample has a length of 5-20 Mu m, a height of 4-10 Mu m and a thickness of 50-100 nm. A displacement control mode is used, maximum displacement is 200-1000 nm, and loading speed is 10-30 nm/s. The transmission electron microscope in-situ nano indentation method for single nano-twin crystal is achieved herein.

Description

technical field [0001] The invention belongs to the technical field of in-situ mechanical testing of transmission electron microscopy, relates to the field of in-situ mechanical testing of nanomaterials, in particular to the field of in-situ nano-indentation testing of nano-twinned transmission electron microscopy, and specifically provides a micron alloy containing a single nanometer of equal length. Twinned in situ nanoindentation method for transmission electron microscopy. Background technique [0002] In 2004, "Science" reported that the tensile strength of nano-twinned copper is 10 times that of coarse-grained copper, and maintains plasticity and electrical properties, followed by "Science" in 2009, and "Nature" in 2010 reported the highest nano-twinned copper Tensile strength, "Nature" reported nano-twinned cubic boron nitride and nano-twinned diamond in 2013 and 2014. Therefore, nano-twinned materials have become an international frontier and research hotspot in the...

AI Technical Summary

Problems solved by technology

Due to the limitations of in-situ mechanical testing methods and instruments of transmission electron microscopy, the length and height of the test sample are required to be several microns, and contain single nanotwins of equal length. This kind of sample is difficult to obtain from the current four methods

[0004] TEM in situ nanomechanics is an effective method to study the nanoscale deformation of nanotwins, but the current research methods mainly focus on the stretching, compression and bending of elemental elements, and there are few reports on in situ nanomechanics of alloys.

[0005] TEM nanoindentation usually uses a needle tip with a radius of curvature of tens of nanometers to indent a sample with a thickness of nanometer scale. If the sample is thick, the electron beam cannot be transmitted, and the sample is thin. It is difficult for the nanoscale diamond tip to press into the sample, and When operating, the line of sight is perpendicular to the direction of pressing, so the operation is extremely difficult

TEM in situ nanoindentation method leading to microalloys containing single nanotwins of equal length is difficult to achieve

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