Since 1977, we have developed specialized software and apparatus designed to achieve the maximum accuracy possible in a laboratory environment. Lambda Research provides residual stress measurement by x-ray diffraction in virtually all polycrystalline metals and ceramics with a suitably small grain size. Residual stress measurements can be performed at the surface or as a function of depth. The subsurface residual stress distributions are corrected for the penetration of the radiation into the subsurface stress gradient, and for stress relaxation caused by sectioning or layer removal by electropolishing in accordance with SAE J784a and ASTM E915 and E1426.
Portable instrumentation is available for massive specimens and field use.
Lambda Research has developed unique capabilities for automated subsurface residual stress measurement and stress contour mapping. The magnitude and depth of residual stress distributions can be determined to optimize manufacturing processes such as shot peening, machining, grinding, welding, stress relieving, quenching, forming, induction hardening, etc. The surface and subsurface principal residual stress magnitudes and orientation can be calculated for directional processes such as machining and welding. Residual stress maps can be prepared for surface or subsurface distributions. The StressPro SM automated apparatus developed at Lambda Research provides cost effective subsurface stress distributions for quality control of shot peening, induction hardening, grinding, etc.