Traceable in-situ micro- and nano-indentation testing instrument and method under variable temperature conditions

A traceable in-situ micro- and nano-indentation testing method under variable temperature conditions, through a traceable in-situ micro- and nano-indentation testing instrument under variable temperature conditions, wherein the testing instrument comprises a vacuum or ambient chamber module, a gantry beam, a macro-micro switchable mechanical loading module, a nano mechanical loading module, an indentation position optical positioning module, an optical microscopic in-situ observation or alignment module, a metal bellows, an air floating vibration isolation platform, an optical breadboard, a marble pedestal, a function switchable module and a contact or ambient mixed variable temperature module, wherein the macro-micro switchable mechanical loading module, the nano mechanical loading module and the indentation position optical positioning module are fixed on the gantry beam, and mechanical loading axes and optical imaging axes are laterally coincided by regulating thicknesses of shims;

• an optical imaging axis of the optical microscopic in-situ observation or alignment module and a loading axis of the nano mechanical loading module are coplanar, the optical microscopic in-situ observation or alignment module and the function switchable module are mounted on a table top of the marble pedestal in a nonintervention manner, and the contact or ambient mixed variable temperature module is fixedly mounted on the function switchable module;
• and a sinking tank is milled in a lower end surface of the marble pedestal which is mounted on the optical breadboard, the optical breadboard guarantees airtightness of the vacuum or ambient chamber module through the metal bellows to be further connected with the air floating vibration isolation platform, to isolate medium-frequency and high-frequency vibration noises outside the device;
• wherein, the testing method is configured for a variable-temperature micro-zone mechanical property in-situ testing and traceability calibration for a block or thin film material based on an indentation test, and comprises following steps:
• replacing the functional indentation tip at the tail end of the indentation holder of the macro-micro switchable mechanical loading module with a standard aluminum lens, regulating an axis of a laser interferometer probe to coincide with that of the standard aluminum lens through a laser interferometer adjusting frame, and performing traceability calibration on an indentation displacement for an air indentation of the macro-micro switchable mechanical loading module at a room temperature;
• removing oxygen and water vapor in the chamber by repeatedly replacing ambient through a vacuum pump assembly and a compressing ambient gas cylinder of the vacuum and ambient chamber module to enable an ambient pressure in the chamber to be close to an atmosphere pressure, starting an internal circulating pump, forming a continuous variable temperature ambient loading environment through inert ambient by a refrigerating unit and a temperature control resistance wire, and performing the traceability calibration on the indentation displacement of the air indentation for the macro-micro switchable mechanical loading module under variable temperature conditions;
• bonding a block sample onto a surface of the negative pressure adsorption tank substrate through low-temperature varnish, and performing a linear point exchange for an indentation position through the contact or ambient mixed variable temperature module placed on the closed-loop large-stroke function switchable platform;
• or placing the block sample in a groove of the thermal insulation framework, firmly absorbing the testing samples through the negative pressure adsorption tank substrate by controlling a switch of a negative pressure adsorption pump, dragging the thermal insulation framework by the two-dimensional stick-slip piezoelectric point exchange platform to perform the point exchange in a plane, accurately positioning a point exchange position through the indentation position optical positioning module, providing the optical contact reference ring at the tail end of the indentation holder, detecting displacement signal increment variation through the optical-approaching laser interferometer probe assembly, driving the indentation holder by the first direct-current servo displacement driving platform to rapidly approach the testing samples, and then utilizing the large-stroke pre-loading piezoelectric actuator to perform precise driving and loading.