Residual Stress Measurement by XRD
- 3 days ago
- 3 min read
At TCR, we continue to push the boundaries of materials testing and structural integrity evaluation. In line with our mission to provide cutting-edge solutions to the industries we serve, we are proud to announce the launch of our Residual Stress Measurement by X-Ray Diffraction (XRD) — a non-destructive, precision technique performed in compliance with ASTM E2860-20.
Why Measure Residual Stress?
Residual stresses are locked-in stresses within a material even in the absence of external forces or loads. They can arise due to welding, machining, casting, rolling, or heat treatment processes and play a crucial role in:
Fatigue life
Crack initiation and propagation
Corrosion resistance
Distortion during service
Dimensional stability of components
Understanding and controlling residual stress is key to ensuring product reliability, especially in high-performance sectors such as aerospace, automotive, energy, petrochemical, defense, and advanced manufacturing.
Our New Capability: X-Ray Diffraction (XRD) for Residual Stress
Residual Stress Measurement setup (currently done using XRD machine at partner lab and will be soon done in-house) is based on X-ray diffraction (XRD), the industry-standard technique to accurately determine the magnitude and orientation of residual stresses at and near the surface of crystalline materials.
We are fully aligned with ASTM E2860-20, which provides the latest standardized practices for XRD-based stress measurements, ensuring our clients receive data that is traceable, reliable, and globally accepted.
How XRD Measures Residual Stress – The Principle Explained
General XRD Peak Principle
When a material is irradiated with X-rays, the crystalline planes diffract the X-rays in specific directions according to Bragg's Law:
nλ = 2d sinθ
λ is the X-ray wavelength
d is the interplanar spacing
θ is the diffraction angle
n is the order of reflection
A detector records the diffraction peaks, and their precise position (2θ) reveals the spacing between atomic planes (d-spacing).
Residual Stress Measurement Principle
Stress alters the spacing between atoms. When a material is under stress, the lattice planes expand or contract, causing a measurable shift in the diffraction angle (Δθ).
By measuring this shift at different tilt angles (ψ), the corresponding strain components are calculated. From these strain values, using elastic constants (Young’s modulus and Poisson’s ratio), we determine the residual stress using the fundamental relationship:
σ = E / (1 + ν) * (Δd / d₀)
Where:
σ = Residual stress
E = Young’s modulus
ν = Poisson’s ratio
Δd = Change in interplanar spacing
d₀ = Stress-free reference spacing
This process is non-destructive, highly accurate, and applicable to a wide range of metallic and ceramic components.
Key Features of TCR’s XRD Residual Stress Measurement
✅ Conforms to ASTM E2860-20
✅ Non-destructive: Surface or near-surface measurements
✅ High spatial resolution: Spot sizes as small as 1 mm
✅ Quantitative: Tensile or compressive stress values in MPa
✅ Versatile: Suitable for welds, machined parts, coatings, castings, and more
✅ On-request stress depth profiling using layer removal or electropolishing
Applications
Welds and heat-affected zones (HAZ)
Shot-peened and cold-worked components
Aerospace turbine blades and engine parts
Automotive transmission and suspension parts
Additively manufactured (3D printed) metals
Coatings and surface treatments
Why Choose TCR?
With over five decades of metallurgical expertise and a reputation for precision, TCR is trusted by global industry leaders. Our investments in the latest XRD equipment and training ensure that our clients gain deep insights into stress behavior — critical for product performance, failure prevention, and life prediction.
Let’s Talk Stress – Before It Becomes a Problem!
TCR’s experts are ready to support your material reliability goals. Whether you're qualifying a new process, investigating a failure, or optimizing a product for durability, our Residual Stress Measurement by XRD can give you the confidence to move forward.
