Laser powder bed fusion (LBFP) additive manufacturing is a potential route for the rapid qualification of new materials for use in nuclear reactor design. Process anomalies such as spatter particles can induce lack of fusion (LOF) voids that may adversely affect the material's mechanical performance. This examination of the spatter particle process in a nickel superalloy using X-ray computed tomography and optical microscopy was conducted to identify possible causes for the formation of LOF voids and other variations during LBPF processing.

Residual stress is generally defined as the stress that is retained in equilibrium in a body or material after manufacturing or processing operations or component usage in the absence of any external forces. This article provides an overview of residual stress measurement methods, including diffraction-based, piezo-spectroscopic/Raman, mechanical, ultrasound, and magnetic techniques. It includes a discussion of measurement planning and execution considerations.

This article series explores the indispensable role of characterization in the development of cold spray coatings and illustrates some of the common processes used during coating development.

Ni-ion irradiated NiTi is nearly 50% harder, retains 85% recoverable deformation, and has reduced hysteresis. This work explores the feasibility of using ion beam modification to modulate the austenite to martensite phase transformation in NiTi, thereby achieving novel or localized properties in near-surface regions.

Compared with traditional fatigue testing, the ultrasonic method achieves much speedier results along with the ability to run extremely high test cycles in a reasonable time frame.

This study looks at whether adding an annealing step to the heat treating process has an effect on residual stress and distortion on hypoid gear sets. Test results indicate that the annealing heat treatment introduced between gear set soft cutting and case carburizing helped to minimize distortion.

This case study measures residual stress on a truck axle housing as it goes through the manufacturing process.

Recent advances in hardware and software provide materials testers with improved productivity and enhanced capabilities. This article describes some innovations in testing composites and aluminum alloy formability and new capabilities in digital image correlation and testing machine software.

Residual stress exists in all classes of materials and significantly impacts many facets of product design and manufacturing. This article reviews residual stress formation, types of stresses, and measurement techniques. ASM International is launching a technical committee on residual stress to enable industry-wide collabration and to advance the science of this important phenomenon.

Increasing and controlling particle impact temperature is proving to be beneficial for both process performance and coating properties.

Preventive multi-frequency testing using eddy current ensures heat-treated parts meet specifications.

From its earliest beginnings to today, hardness testing has evolved in a parallel manner to the engineering innovations of the times.

As demand for adherence to VDA standards increases, aluminum testing equipment keeps pace. The VDA, or Verband der Automobilindustrie, is the German association of the automotive industry. Typically, the VDA requirements are adaptations to existing ISO standards with more stringent requirements that aim to reduce variability between labs.

Tests conducted on vacuum carburized and quenched shafts identify variables that increase distortion and the magnitude of residual stresses.

Induction hardening parts with small grain size achieves higher fracture strengths, but close control of thermal cycles is required to prevent grain growth.

As powder-based additive manufacturing (AM) processes continue to mature, reliable powder characterization techniques will be key to optimizing both AM processes and final part performance. This article describes advanced metals for assessing powder properties and their influence on AM processing and part performance.

Process optimization and optimal component performance can be achieved when multiple variables are measured and studied as a whole. In the investigation described in this article, fatigue performance of AISI 8620 H steel was characterized as a function of carburization case depth, hardness, residual stress, and retained austenite to demonstrate that an optimized carburization process could be engineered to meet specific application requirements.

Recently developed open-source software based on standard test and normalization methods simplifies the process of generating J-integral versus crack-growth resistance (J-R) curves to evaluate fracture toughness in the ductile region.

Advances in software algorithms and design enable automation of microstructure image analysis, leading to cost savings, reduction in measurement variability, and access to important metrics.

Deformation-induced martensite phase transformation during room temperature forming of austenitic stainless steel leads to higher residual stress. This article discusses the results of a study to determine the relationship between deformation-induced martensite phase transformation and residual stress in AISI Type 304 austenitic stainless steel (nominal 18% Cr, 8% Ni) after stamping.