Material Characterization

Understanding Magnetic Testing and Standards

Magnetic testing is a critical process used to ensure the quality and performance of a wide range of products and materials. The process involves measuring the magnetic properties of a material, such as its magnetic field, magnetic strength, and magnetic susceptibility.

In this article, we will discuss the different types of magnetic testing methods and the various standards that are used to evaluate magnetic materials. We will also provide an overview of the most common applications of magnetic testing in the manufacturing and engineering industries.

Types of Magnetic Testing

There are several different types of magnetic testing methods, including:

Magnetic field measurement: This method involves measuring the strength and direction of a magnetic field.
Magnetic susceptibility measurement: This method measures the ability of a material to be magnetized.
Magnetic force measurement: This method measures the strength of the magnetic field at a specific point.
Magnetic leakage field measurement: This method measures the strength of the magnetic field outside of a specific area.

Standards for Magnetic Testing

There are a variety of international standards for magnetic testing, including those set by the International Organization for Standardization (ISO) and the American Society for Testing and Materials (ASTM). These standards provide guidelines for testing procedures, measurement methods, and acceptable levels of magnetic properties.

Applications of Magnetic Testing

Magnetic testing is used in a variety of industries, including manufacturing, engineering, and metallurgy. Some of the most common applications include:

Quality control in the production of magnetic materials
Evaluating the performance of motors, generators, and other electrical equipment
Assessing the integrity of pipelines and other structures in the oil and gas industry
Evaluating the quality of welds in the construction industry

Conclusion

Magnetic testing is an essential process used to ensure the quality and performance of a wide range of materials and products. With a variety of testing methods and international standards available, it is important for manufacturers and engineers to understand and adhere to these guidelines in order to ensure that their products meet industry standards and perform at their best.

Magnetic and Electric Measurement

Keysight (Agilent/HP) E4991A 3GHz RF Impedance/material Analyser Description:

The E4991A RF impedance/material analyzer offers ultimate impedance measurement performance and powerful built in analysis function. It will provide innovations in R&D of components and circuit designers who evaluate components in the range of 3 GHz. The E4991A uses an RF-IV technique, as opposed to the reflection measurement technique, for more accurate impedance measurement over wide impedance range. Basic impedance accuracy is +/-0.8%. High Q accuracy enables low-loss component analysis. The internal synthesizer sweeps frequency from 1 MHz to 3 GHz with 1 mHz resolution.

Basic Accuracy

+/- 0.8 % basic accuracy

Sweep Parameters

Frequency: 1 MHz to 3 GHz
Oscillator level: Up to 1 dBm/0.5 Vrms/10 mArms
DC bias level (Option E4991A-001): +/- 40V or +/- 50 mA

Versatile Measurement Options

Dielectric/magnetic material measurement (Option E4991A-002)
Reliable on-wafer measurement (Option E4991A-010)
Temperature characteristic measurement (Option E4991A-007)

Magnetic Testing--Hysteresisgraph Loop Measurement

The TXEMM-BH01 automatic hysteresisgraph/hysteresis loop tracer is a computer system used for measuring the magnetic properties of soft magnetic materials at frequencies ranging from DC to 1KHz following ASTM standard test procedures, such as ASTM A342, ASTM A343, ASTM A773 and ASTM A977. Testing of magnetic properties is necessary for the selection, production and quality control of magnetic materials used in many industrial applications such as the electric motors, transformers, sensors, speakers, and recording media. TXEMM provides wide range of magnetic properties testing for both the “soft” and “hard” magnetic materials.

Soft magnetic materials/soft magnetic composites are characterized by high magnetic induction, high magnetic permeability, low coercivity, and low loss. The key to accurately determine these parameters is to ensure measured sample forms magnetic close circuit (no end magnetic poles). One example is to make a sample in a ring shape wounded with primary and secondary coils for generating field and detecting magnetic flux.

The magnetic properties that TXEMM can measure for you include:

Saturation magnetization
Maximum, initial and other permeabilities
Remanence and coercive field
Hysteresis loss
DC and AC B-H curve
Epstein frame and ring samples testing for soft-magnetic materials
Demagnetization curve of permanent magnet (testing temperatures up to 200°C)

Vibrating Sample Magnetometer

The Vibrating Sample Magnetometer (VSM) is used to measure the magnetic properties of solids and liquids. The magnetometer measures magnetic moment as a function of an applied magnetic field. A unique feature of this system the ability to measure (inverse) magnetostriction using a special sample holder that strains the sample during measurement.
VSMs can measure the magnetic properties of magnetically soft (low coercivity) and hard (high coercivity) materials in many forms: solids, powders, single crystals, thin films, or liquids. They can be used to perform measurements from low to high magnetic fields employing electromagnets, Halbach rotating permanent magnet arrays, or high-field superconducting magnets. They can be used to perform measurements from very low to very high temperatures with integrated cryostats or furnaces, respectively. And, they possess a dynamic range extending from 10⁻⁸ emu (10⁻¹¹ Am²) to above 10³ emu (1 Am²), enabling them to measure materials that are both weakly magnetic (ultrathin films, nanoscale structures, etc.) and strongly magnetic (permanent magnets).
Under full software automation it can measure and record hysteresis M(H) loops, torque curves, isothermal and DC demagnetisation remanence curves, and temperature dependent magnetic properties.

Features

- 1 × 10^-7 emu noise floor at 10 s/pt
- 7.5 × 10^-7 emu noise floor at 0.1 s/pt
- High stability ±0.05% per day
- Excellent reproducibility
- Fields to >3 T
- Available temperature range—50 K to 1000 K
- Vector, magnetoresistance, and autorotation options

Microwave Property Test

Microwave Test Facility Selection Guide

Stripline Resonant Cavity (SLC)

Complex magnetic permeability (µ ) and dielectric permittivity (Ɛ) within 500MHz~12GHz spanned by 500MHz
Specimen: magnetic and dielectric plates with thickness < 3 mm; height < 12 mm
- - - high accuracy at fixed resonance frequencies
    - bias magnetic field (possible)

Coaxial Transmission Line Fixture (CTLF)

S parameters within 10 MHz ~ 20 GHz complex permeability (µ) and permittivity (Ɛ) extracted

Specimen: electromagnetic materials in ring shape with ID=3mm & OD=7mm
- - - high accuracy (< 2%)
    - easy to extract permittivity and permeability
    - wide frequency range (500MHz-18GHz)

Coplanar Wave Guide (CPW)

S parameters within 500 MHz -14
GHz absorption, reflection, transmission
complex permeability
complex permittivity
specimen: magnetic thin film with thickness <10 µm
- - - bias magnetic field: 0-1000 Oe
    - high accuracy
    - excellent for study Ferromagnetic Resonance (FMR) spectra

Rectangular Wave Guide (RWG)

S parameters spectra at frequency bands (in GHz):
- - - S band: 2.60-3.95
    - G-band: 3.95-5.85
    - C-band: 5.85-8.20
    - X-band: 8.20-12.4
specimen: electromagnetic material in the rectangular plate form
- - - high accuracy ( & <2%, loss <5%)
    - wide frequency band (2.6GHz-12.4GHz)

X-ray Diffraction

The Rigaku IV X-ray Diffractometer

This is a versatile, sensitive, and high resolution X-Ray powder diffractometer. The monochromatic Cu Kα1 line is isolated by the Vario monochromater at the X-Ray tube.

No more need to numerically subtract out the Kα2 from your data.

A LynxEye position sensitive detector permits up to 4 ° 2θ of diffracted beam to be measured continuously while scanning, which dramatically increases sensitivity compared with the conventional scintillation detector behind a narrow slit.

Energy Dispersive Spectroscopy (EDS)

Energy Dispersive Spectroscopy (EDS) is a standard procedure for identifying and quantifying elemental composition of sample areas of a micron or less. The characteristic X-rays are produced when a material is bombarded with electrons in an electron beam instrument, such as a scanning electron microscope (SEM). Detection of these x-rays can be accomplished by an energy dispersive spectrometer, which is a solid state device that discriminates among X-ray energies.

Technique Advantages

Rapid elemental analysis of small features
Two-dimensional elemental mapping
Semi-quantitative analysis with standards
High count rates at low kV and beam current

Typical Applications

Elemental identification of material

Sample Requirements

Any vacuum compatible solid (thin films, powders, fibers, bulk materials)
Highly polished mirror surface (preferred)

Electron Microscopy

JEOL JSM 6330F Field Emission Scanning Electron Microscope

This is a ultra-high vacuum scanning electron microscope with cold field emission electron source enabling high resolution imaging. Fitted with IXRF Systems secondary electron detector and solid state backscattered detector for elemental analysis and mapping. Images stored digitally.

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