The Non-Destructive Testing (NDT) lab in the Advanced Steel Research Centre focuses on electromagnetic (EM) sensing for microstructure characterisation and contains a range of facilities to support the EM work:
1. Impedance analyser
Virtually every liquid and solid is able to pass a current when a voltage is applied to it. If a variable (ac) voltage is applied to the material, the ratio of voltage to current is known as the impedance. The measured impedance varies with the frequency of the applied voltage in a way that is related to the properties of the liquid or solid. This may be due to the physical structure of the material, to chemical processes within it or a combination of both.
The model 1260 Impedance/Gain-Phase Analyser is one of the most powerful, accurate and flexible Frequency Response Analyser available. Within the EM sensor NDT group we use the system with a range of in-house built EM sensors to obtain inductance verses frequency plots for different steel samples allowing us to develop relationships between the EM signal and steel microstructure.
|ac Amplitude ≤10MHz
|0 to 3V rms
0 to 1V rms
|0 to 60mA rms
0 to 20mA rms
|Maximum ac resolution||5mV||100µA|
|dc bias range||±40.95V||±100mA|
|Frequency||range:10µHz to 32MHz, max resolution: 10µHz frequency (log or lin) ac/dc voltage, ac/dc current|
2. LR Mate 200iD Robotic arm - with the laser range sensor
The LR Mate 200iD is a compact six-axis mini robot with the approximate size and reach of a human arm
• Max. reach: 717 mm
• Max. load capacity at wrist: 7 kg
• Max speed: 450-1000 °/s
• Repeatability: ± 0.02 mm
• Advanced servo technology and highly rigid arm enable smooth motion without vibration in high-speed operations
• Working with the laser range sensor (measurement range 50±10 mm with 0.025 μm repeatability) to allow accurately in-line inspection on components with complex geometry (for defects, microstructure, roughness, profile and positioning measurements and inspections, etc).
• Holding an EM sensor at an accurate lift-off to the testing sample and automatically doing grid scanning for signal mapping.
3. Xstress 3000 G3 (X-ray stress analyser)
The Xstress 3000 system is an advanced X-ray stress analyser based on solid state linear sensor technique that enables converting X-rays directly into electrical signal.
X-ray diffraction is the conventional and time proven technique for measuring residual stresses. Using the interatomic spacing as the ultimate gauge length, the X-ray technique is ideal for and applicable to all crystalline materials, especially for metals, but also for ceramics. It measures the absolute stress without the need for an unstressed sample for calibration.
4. Magnetic Hysteresis Analyser and In-situ Magnetic Domain Imager
The system consists of an in-house Magnetic Hysteresis Analyser, an Axioscope optical microscope featuring polarised light and extra z spacing enabling the setup of a magnetising rig to apply a magnetic field, a high-sensitivity high-speed camera for magnetic domain structure and domain wall movement imaging and a data syncing kit to sync high speed video with magnetic hysteresis data.
Magnetic Hysteresis Analyser
• Major and minor loop measurement
• Magnetic Barkhause Noise (MBN) analysis
• Independent field measurement
Magnetic Domain Imager
• Dynamic domain imaging by Bitter method
• In-situ magnetic hysteresis (BH loop) measurements
• Syncing high speed video with BH data
• Magneto-Optic Kerr effect ready