A method for acoustically measuring material properties of a test piece at high temperatures, includes the steps of: heating the test piece to within a testing temperature range; performing a background measurement within said testing temperature range by capturing a vibrational signal from the test piece within a calibration period, thereby obtaining a noise signal; performing an acoustic measurement on said test piece within said testing temperature range and within a testing period by: imparting a vibrational excitation onto the test piece; capturing a vibrational signal of the test piece within the testing period, thereby obtaining a vibrational response signal to said vibrational excitation, and obtaining the material properties of the test piece by analyzing the vibrational response signal, thereby taking into account the noise signal. A system is provided for acoustically measuring material properties of a test piece at high temperatures.

A method for testing the nanomechanical properties of natural gas hydrate samples is provided. A dry pure nitrogen environment and a partial ultralow-temperature liquid nitrogen test condition are constructed, a micro-positive pressure state in a glovebox is maintained, and the temperature of a milling tool and a sample stand are maintained consistent; then, a hydrate sample is transferred and installed in the dry nitrogen environment, and the milling tool is driven to cut a surface of the natural gas hydrate sample to form a relatively flat surface; next, indentation parameter reliability testing is performed, an indentation load is changed, indentation testing of indentation points is performed, and an indentation form is observed. The method can realize indentation testing of natural gas hydrate samples in an ultralow-temperature and dry environment by means of a nanoindenter.

A method for testing the nanomechanical properties of natural gas hydrate samples is provided. A dry pure nitrogen environment and a partial ultralow-temperature liquid nitrogen test condition are constructed, a micro-positive pressure state in a glovebox is maintained, and the temperature of a milling tool and a sample stand are maintained consistent; then, a hydrate sample is transferred and installed in the dry nitrogen environment, and the milling tool is driven to cut a surface of the natural gas hydrate sample to form a relatively flat surface; next, indentation parameter reliability testing is performed, an indentation load is changed, indentation testing of indentation points is performed, and an indentation form is observed. The method can realize indentation testing of natural gas hydrate samples in an ultralow-temperature and dry environment by means of a nanoindenter.

An indentation tester and indentation method for testing a sample heated at a temperature range from above 800? C. to 1200? C., and above, is disclosed. The indentation tester includes a stage having a metallic cylindrical base that houses an inner cylindrical base made of a temperature resistant material sufficient to maintain shape over the range of the heating temperature. A removable crown fastens to the cylindrical base and includes a ring that holds an axisymmetric pipe made of a temperature resistant material sufficient to maintain shape over the range of heated temperature. A nut is turned to tighten the pipe which secures the sample and guides an indenter to penetrate the sample. The indenter includes a rod made of temperature resistant material and a indenter tip.

An indentation tester and indentation method for testing a sample heated at a temperature range from above 800? C. to 1200? C., and above, is disclosed. The indentation tester includes a stage having a metallic cylindrical base that houses an inner cylindrical base made of a temperature resistant material sufficient to maintain shape over the range of the heating temperature. A removable crown fastens to the cylindrical base and includes a ring that holds an axisymmetric pipe made of a temperature resistant material sufficient to maintain shape over the range of heated temperature. A nut is turned to tighten the pipe which secures the sample and guides an indenter to penetrate the sample. The indenter includes a rod made of temperature resistant material and a indenter tip.

Disclosed herein are systems, devices and methods for creep testing selected materials within a high-temperature molten salt environment. Exemplary creep testing systems include a load train for holding a test specimen under a load within a heated inert gas vessel. An extensometry system can be included to measure elongation of the test specimen while under load. The extensometry system can include fixed members and axially translating member that move along with the elongation of the test specimen, and the system can include a sensor to measure the relative axial motion between such components to measure elongation of the test specimen over time. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during creep testing to simulate the corrosive effect of the molten salt on the specimen material during testing.

Disclosed herein are systems, devices and methods for creep testing selected materials within a high-temperature molten salt environment. Exemplary creep testing systems include a load train for holding a test specimen under a load within a heated inert gas vessel. An extensometry system can be included to measure elongation of the test specimen while under load. The extensometry system can include fixed members and axially translating member that move along with the elongation of the test specimen, and the system can include a sensor to measure the relative axial motion between such components to measure elongation of the test specimen over time. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during creep testing to simulate the corrosive effect of the molten salt on the specimen material during testing.

A thermometric powder metal material for testing to replicate an actual powder material during use of the actual powder metal material in an internal combustion engine is provided. The thermometric powder metal material includes pores and has a decrease in hardness as a function of temperature according to the following equation: D Hardness/D Temperature=>0.5 HV/ C. The properties of the actual powder metal material, when the actual powder metal is used in an internal combustion engine, can be estimated using the thermometric powder metal material by first adjusting the thermal conductivity of the thermometric powder metal material or controlling the porosity of the thermometric powder metal material to replicate the actual powder metal material, and then subjecting thermometric powder metal material to an engine test. For example, the thermal conductivity can be adjusted by infiltrating the thermometric powder metal material with copper.

A measurement apparatus for carrying out an indentation creep test on a specimen, including a measurement control apparatus that includes a load measurement device, a constant-load compression device configured to compress a tip of a transparent indenter to a surface of the specimen, and an image capturing device configured to optically capture an image including a contact area portion which is a part of the specimen to which the load is applied by the constant-load compression device. The apparatus also includes an information processing apparatus that includes an image analysis unit configured to analyze a contact area, and a physical property value calculation unit. The physical property value calculation unit conducts linear regression with respect to a plot of a logarithmic value of the contact stress and a logarithmic value of the contact strain rate so as to determine a creep index n and creep constant k.

A measurement apparatus for carrying out an indentation creep test on a specimen, including a measurement control apparatus that includes a load measurement device, a constant-load compression device configured to compress a tip of a transparent indenter to a surface of the specimen, and an image capturing device configured to optically capture an image including a contact area portion which is a part of the specimen to which the load is applied by the constant-load compression device. The apparatus also includes an information processing apparatus that includes an image analysis unit configured to analyze a contact area, and a physical property value calculation unit. The physical property value calculation unit conducts linear regression with respect to a plot of a logarithmic value of the contact stress and a logarithmic value of the contact strain rate so as to determine a creep index n and creep constant k.