The Young's modulus, shear modulus, bulk modulus, and Poisson's ratio of a material describe its basic mechanical properties, which are crucial for material manufacturers and researchers. The search for a simple and accurate technical means to measure the modulus of materials has always been a topic of interest for condensed matter physicists, engineers, and materials scientists. After verifying various methods and technical means such as RUS, IE, NI, 4PB, the advantages and disadvantages of each technology gradually became clear. Traditional tensile and compression tests for measuring elastic modulus cannot meet certain high-precision measurement requirements. TECLAB provides corresponding solutions based on the characteristics of the tested material:

Resonant Ultrasound Spectrometer /RUSpec The ultrasonic resonance spectrum analysis method obtains the elastic modulus value of the material by measuring the ultrasonic resonance spectrum of regular samples. The size of solid hard material samples measured can range from a few millimeters to over ten centimeters, and the testing temperature can range from liquid helium to over 1850 degrees Celsius. The measurement results of this technology reflect the overall mechanical properties of the sample, avoiding the conventional method of obtaining results at a certain point or direction. The sample can be very small, especially suitable for measuring the modulus of finite size material samples. In addition, the greater advantage is that anisotropic materials can also obtain all independent elastic constants through one measurement. It saves a lot of time while greatly improving accuracy.

The testing process is roughly as follows: the software first calculates the elastic constant and resonance frequency of the material based on the size and weight of the test sample; Interactively measure the actual resonance frequency of the sample, and then use the Levenberg Marquardt iterative scheme (iterative elastic constant value) to find the best match between the measured resonance frequency value and the calculated resonance frequency value. Calculate various modulus values using the best matching elastic constant values and generate a detailed test report (including sample information, test data, results, errors, etc.). When the material is homogeneous and the sample shape is regular, the accuracy of this scheme can reach 0.01%.

The crystal structures that can be measured by ultrasonic resonance spectroscopy analysis include:

Isotropic isotropy

• Cubic Cube

Hexagonal hexagon

Tetragonal Square

Orthohombic orthogonality

A single measurement of anisotropic materials can simultaneously obtain all independent elastic constants

The standard measurement results for isotropic materials include:
Poisson's Ratio

Young's Modulus Young's modulus

Shear Modulus Shear Modulus

• Bulk modulus of elasticity

Shear Sound Velocity

Longitudinal Sound Velocity

After numerous studies and comparisons by institutions and scholars, this technology has become internationally recognized as the most ideal means for measuring material modulus research.

Advanced Ultrasonic Material Characterization system/UMSThe advanced ultrasonic material characterization system uses ultrasonic echo analysis or ultrasonic transmission method to calculate the elastic modulus value by measuring the transverse wave, longitudinal wave velocity, and density of the sample material. It is recommended to measure the thickness of the sample using the echo method at least 1cm thick. The test surface and the reflection surface should be smooth and parallel to each other, and the width or diameter of the test surface should be greater than that of the transducer. For anisotropic materials, the elastic parameters will vary along different directions and need to be measured separately in each direction. This technology can measure material attenuation while measuring sound velocity.

The testing process is roughly as follows: first, measure the density and acoustic path of the sample (from the test surface to the reflection surface), then use the echo method to measure the longitudinal and transverse waves, and finally calculate the longitudinal and transverse wave velocities and elastic modulus.

UMS is suitable for most isotropic metals, ceramics, and glass materials. It has the function of separately amplifying weak signals with secondary echoes, and has a wide range of applicability.

For isotropic, bulky sample materials with low precision requirements, UMS can be used for measurement.

Surface Acoustic Wave  SpectrometerThe surface acoustic wave analysis method excites surface acoustic waves on the sample surface through laser pulses. After the surface waves propagate a certain distance on the sample surface, they are received for analysis. By analyzing the dispersion curve of the surface wave phase velocity, parameters such as modulus, thickness, and density are calculated and analyzed. As the thickness of the film becomes thinner, measuring its mechanical properties becomes very difficult. When the film thickness is less than 200nm, conventional indentation methods cannot obtain accurate results. The SAW surface acoustic wave method overcomes the difficulty of accurately measuring the mechanical properties of ultra-thin films. The technical features are as follows: non-destructive measurement and evaluation, film thickness can range from a few nanometers to millimeters, samples do not require special preparation, multiple layers can also be characterized, fast measurement cycle, high repeatability of results, no need for calibration, etc.

SAW technology has achieved significant results in the measurement and research of a large number of thin film materials:

Thin film materials

-Ceramic film (TiN, Al2O3, SiC, TiC,ZrO2)

- diamond-like carbon

- CVD diamond

- boron nitride

- metals

- polymers

-NiNb amorphous film

Substrate material

- steel

- aluminum

- silicon

- GaAs

Atomic Force Acoustic MicroscopeUltrasonic atomic force microscopy imaging can analyze the surface modulus distribution of materials at the scale of 100 micrometers to nanometers. This technology is based on scanning probe imaging technology, which utilizes van der Waals forces between atoms to present the surface characteristics of the sample. Coupling the sample onto an ultrasonic transducer, the transducer emits longitudinal waves to excite the sample, causing the surface of the sample to vibrate. Using a micro cantilever to sense the interaction between the needle tip and the sample surface, this force will cause the cantilever to swing. Then, using laser to irradiate the end of the cantilever, when the swing is formed, the position of the reflected light will change, causing a displacement. At this time, the laser detector will record this displacement and provide the signal to the feedback system for appropriate adjustment. Finally, this signal is lock-in amplified with the transducer signal to obtain the surface characteristics of the sample. In addition to obtaining the modulus imaging distribution image, the surface morphology image is also obtained.

The technical features are as follows:

At present, advanced scanning detection microscopy technology can obtain surface elastic property distribution images of materials at the nanoscale.

Can measure the elastic properties of thin films.

Make numerical calculations of hardness and Young's modulus possible.

The contrast of the image is much better than that obtained by other methods.

Can be measured in both air and liquid environments.

It is a non-destructive method.