Search Results for X-ray radiography

This article summarizes the more common analytical techniques for studying ancient metal artifacts, illustrated by case histories. There are two main classifications: noninvasive and invasive techniques. This distinction is of prime importance because some heritage objects may be too rare or valuable for invasive sampling, or there may be ethical objections to certain types of examination. Noninvasive examination of ancient metal artifacts is important, yet it cannot provide the detailed information obtainable from invasive techniques. This is especially true when artifacts contain “hidden” damage and there is also a need for accurate quantitative analyses.

A metallurgical study of a 10th century iron-base nail from the central-East coast of Tunisia reveals how early metallurgists without modern scientific knowledge created parts with engineered properties.

This article provides an overview of nondestructive test methods and their application in the study of material properties and structures. It covers the most widely used NDT technologies, including optical examination, radiography, acoustic emission, and ultrasonic testing, and discusses the impact of recent advancements.

Use of radiography to inspect insulated generator components without the need to strip insulation offers advantages over other inspection methods to assess serviceability and need for repair. This article outlines some of the considerations involved in using nondestructive radiography techniques to assess component integrity.

Neutron-based imaging and measurement techniques are an ideal complement to x-ray methods for characterizing additively manufactured materials and components. This article presents examples showing how neutron radiography and residual strain measurements reveal the internal structure and stress distributions in highly engineered turbine blades produced by additive processes. It also discusses the development of neutron characterization tools at ORNL and a recent effort in which they were used to evaluate stress-relief treatments for large-scale metal AM structures.

Wavelength-dependent or hyperspectral imaging is a novel nondestructive characterization technique in the field of neutron radiography and computed tomography. A dedicated facility named VENUS is currently being built at Oak Ridge National Laboratory to provide these characterization capabilities for academia, industry, and other national laboratories. This feature article describes the VENUS capabilities for materials science and engineering, provides a quick overview of the modes of access of the facility, and illustrates the nondestructive measurements and interpretation of results.

Nondestructive evaluation comprises a large family of specific test disciplines including visual inspection, dimensional metrology, ultrasound, radiography, penetrant tests, magnetic particle tests, leak tests, eddy current tests, potential drop tests, flash and vibrothermography, shearography, acoustic emissions, and many other methods. This article offers an overview of NDE science and discusses some key considerations for choosing specific techniques.

Recent advances in neutron sources and detector technologies enable new contrast mechanisms to determine crystalline information for metal components. This new capability can help validate emerging additive manufacturing processes used to produce parts with complex geometries.

Acoustic micro imaging is widely used for inspecting IC packages, but readily adapts for the detection of defects in parts and assemblies up to 1 m or more on a side. This article describes a typical imaging setup consisting of a scanning acoustic microscope and water tank and presents examples in which it was used to detect delaminations in solar panels and clogs in brazed aluminum-copper cooling-ring assemblies. It also explains how to deal with issues that arise when scanning large-area parts.

Forensic metallurgy investigations in archaeology and aerospace engineering follow similar technical protocols but serve different objectives. Archaeometallurgical analyses focus on artifact provenance and cultural heritage management with minimal invasive sampling, while aerospace investigations prioritize rapid failure analysis for operational problems. Four case studies illustrate the approaches: noninvasive macrophotographic analysis of an ancient silver cup revealed stress corrosion cracking, noninvasive investigation of a Boeing 747 accident identified fatigue failure in fuse pins due to inadequate load knowledge, invasive lead isotope analysis successfully provenanced Chinese bronzes using kernel density methods, and comprehensive testing of F-16 wing bolts ruled out hydrogen embrittlement. Both fields employ similar analytical techniques, including microscopy, fractography, and chemical analysis, but differ in sampling constraints, time pressures, and reporting goals, with successful investigations in both domains requiring interdisciplinary teamwork.

In Germany, the Federal Institute for Materials Research and Testing (BAM) is addressing challenges in the implementation of additive manufacturing on the industrial landscape for safety-critical applications. This article provides an overview of BAM’s activities in additive manufacturing with a focus on safety (both for applications and the environment) and AM technology innovation for a wide range of materials and manufacturing locations.

An industry pioneer shares a historical overview of the early days of single crystal superalloy development.

News about ASM members, chapters, events, awards, conferences, affiliates, and other society activities. Topics include: ASM announces the nominees for ASM vice president and trustee for 2017-18 and three members of the Board of Trustees for 2017-2020; profiles for nominated officers; update on the ASM Renewal from ASM President William E. Frazier; the ASM Failure Analysis Society announces nominees for officers and directors; professional profile for Margaret Flury.

News about ASM members, chapters, events, awards, conferences, affiliates, and other society activities. Topics include: 2015 class of ASM Fellows; ASM holds its first-ever Affiliate Summit in July 2015; spotlight for ASM Handbook, Volume 7 editors Prasan Samal and Joseph Newkirk.