Application Cases

Experimental Name: Application of Power Amplifier ATA-309C in Wear State Detection of Ferromagnetic Materials Using MBN

Experimental Direction: Nondestructive Testing

Experimental Equipment: ATA-309C power amplifier, signal generator, filter, NI acquisition card, etc.

Experimental Objective:
This experiment evaluated the wear degree of AISI1045 steel using the Magnetic Barkhausen Noise (MBN) testing method. The Root Mean Square (RMS) and Full Width at Half Maximum (FWHM) of MBN were extracted to establish a quantitative relationship between tribological indicators and stress state.

Experimental Process:

A test platform was constructed using a signal generator, ATA-309C power amplifier, MBN sensor, and NI acquisition card. The signal generator provided a sinusoidal wave with a frequency of 2 Hz and voltage of 6 V, which was amplified by the low-frequency power amplifier Aigtek ATA-309C to magnetize the sample.

Each time the disk sampling reached the preset rotation cycle, the data acquisition card recorded the MBN signal at the wear scar with a sampling rate of 2.5 MHz and a bandpass filter of 0.001-1.25 MHz. The RMS and FWHM of the MBN characteristic values were extracted to further evaluate the damage degree of the worn sample.

Experimental Results:

During the wear process, the RMS linearly decreased with the increase of tribological indicators such as wear rate m, surface roughness Sa, and average depth Sz. However, the relationship between RMS and residual compressive stress σ exhibited a complex nonlinear pattern. The FWHM showed quadratic growth with the increase of both tribological indicators and stress.

The RMS and FWHM characteristic values can reflect the influence of plastic deformation and stress state on MBN signals, distinguishing different stages of abrasive wear, adhesive wear, and fatigue wear.

Parameters of the ATA-309C Power Amplifier Used in the Experiment: