Search Results for specimen geometry

This article identifies several factors that are not fully addressed in most fracture toughness test standards and explains how they may influence calculated values obtained from ferritic steels. Of particular consequence are test temperatures within the ductile-to-brittle transition regime and test specimen geometries when measuring the toughness of weld metal and heat-affected zones.

Digital image correlation data and Bayesian inference used together facilitate rigorous quantification of the uncertainty in material input parameters for finite element simulations of superelastic deformation.

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.

Orion’s Exploration Flight Test 1 vehicle used four additively manufactured vent assemblies to equalize pressure between unpressurized portions of the spacecraft and the external environment.

Modeling and simulation are proving to be an effective alternative to the trial-and-error practices often used when developing and evaluating nondestructive tests for materials characterization. This article demonstrates the benefits of modeling in different cases where eddy current and ultrasonic inspection methods are employed.

Powder metallurgy offers distinct advantages for the production of certain alloys. The degree to which contents of the alloy may be prescribed represents tremendous potential and supports alloy use in new applications. However, robust testing of powder metallurgy alloys is required to assess their potential and quality. Fatigue testing via the resonance principle enables metallurgists to achieve greater throughput in testing programs, while novel hardness testing platforms support analysis of individual phases in porous powder metallurgy specimens.

This article discusses the development and use of a nondestructive evaluation (NDE) method that allows researchers to compare surface crystallographic orientations before and after mechanical testing to determine the impact of surface orientation on material response. Two gage samples were tested, one rectangular (Ti-Al), the other round (IN100). The samples were placed in a SEM equipped with an EBSD detector and a motorized fixture that rotates the test piece as EBSD and imaging data are collected. Inverse pole figure maps of both gage samples are presented.

Researchers at Pacific Northwest National Laboratory (PNNL) use a combination of scanning and transmission electron microscopy, atom probe tomography, and focused ion beam milling to analyze corrosion and crack structures in light-water reactor components with near-atomic spatial resolution.

This article highlights some of the best metallographic practices from a laser powder bed fusion laboratory and provides practical observations of the more universal aspects of powder testing.

A look at how companies in regulated industries can test materials to produce higher quality metal components with additive manufacturing.

This unique testing method offers economic benefits, sustainability advantages, and the potential to slash the time required to develop new alloys and processing recipes.

Additive manufacturing by itself provides many benefits, but by combining different materials processing techniques like traditional casting with additive manufacturing to create hybrid processes, custom materials can be tailor-made and mass produced for applications with specific performance needs. This article reports on research to create metal-metal interpenetrating phase composite materials using additive manufacturing and casting methods in combination.

The ability to make components from copper and copper alloys via additive manufacturing is spurring a range of novel applications. Although the high thermal conductivity of copper presents challenges for direct AM processes, fully dense copper components with complex geometries have been demonstrated. Of particular interest is the ability to use AM methods to fabricate internal cooling channels and mesh structures to optimize thermal management. This article describes feasibility studies to evaluate AM processing of copper parts.

The rapid ability of next-generation EDS detectors to characterize beam sensitive materials is leading to breakthroughs in nanoparticle research.

Shape memory alloy textiles provide complex deformation and force profiles for novel wearable applications.

Researchers at the University of Michigan are investigating the complex heterogeneous phase transformations associated with deformation in shape memory alloys by means of in-situ tensile loading in combination with SEM, EBSD, and digital image correlation. This article describes the general approach and presents and interprets test results.

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.

The Center for Heat Treating Excellence (CHTE) at Worcester Polytechnic Institute (WPI) in Massachusetts is conducting a cutting-edge research project aimed at measuring the surface hardness and case depth on carburized steels for process verification and control. The results will enable companies to improve the quality of heat-treated products faster and more cost-effectively. Nondestructive techniques being evaluated initially include eddy current, meandering winding magnetometer (MWM), Barkhausen noise testing, and alternating current potential drop.

This article provides an update on a three-year three research project by the Center for Heat Treating Excellence aimed at establishing nondestructive techniques for measuring surface hardness and case depth on carburized steels for process verification and control.

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.