Showing papers in "Materials Characterization in 1999"

TL;DR: The probability and appropriate processing parameters for diffusion bonding of a titanium alloy to a stainless steel web with an Ni interlayer have been investigated in this paper, and the microstructure of the diffusion bonding joint has been observed by microscopy, SEM, and EPMA, and the main factors affecting diffusion bonding have been analyzed.

TL;DR: In this article, a low-carbon (0.1%) steel has been subjected to three different heat treatments to obtain dual-phase steels with different microstructures, and the steel with the intercritically annealed microstructure of equiaxed ferrite-martensite exhibited the highest tensile strength, the lowest ductility, and intermediate fracture toughness properties.

TL;DR: In this article, a spatial analysis method for the quantitative discrimination between shrinkage and gas porosity is presented and explained, and it is shown that shrinkage pores can be selected and analyzed separately from gas pores by nearest-neighbor analysis.

TL;DR: In this article, the mechanical properties of similar and dissimilar weld joints were examined by means of microhardness testing, tensile testing, bending fatigue testing, and light optical and scanning electron microscopy.

TL;DR: In this article, the effect of processing on the entrapment of voids in both fiber-free and fiber-bearing syntactic foam systems is studied, and it is found that strength of syntactic foams increased as void content decreased, emphasizing that a good correlation between the two parameters exists.

TL;DR: In this paper, the transverse rupture strength behavior of tungsten carbide blended with 10wt% Co as a function of temperature was investigated, and the results showed that the WC-Co composite suffered a strength loss at temperatures above 600°C.

TL;DR: In this article, high resolution electron microscopy (HREM) revealed a completely coherent transition of the lattice planes from these carbides to the matrix-plane without any irregularities, showing that the high red hardness up to temperatures of approximately 550 C is caused by these nanometer-sized carbides.

TL;DR: In this article, a comparative study has been made between the evolved microstructures of pulsed electrode surfacing (PES) and laser surface engineering (LSE) for ultrahard titanium diboride (TiB2) coatings.

TL;DR: In this paper, a technique for automatically characterizing the three-dimensional geometry of fracture surfaces is presented, which utilizes digital image correlation to provide an accurate and fast method of digitally reconstructing fracture surfaces from stereo pairs produced in the scanning electron microscope (SEM).

TL;DR: In this article, the authors point out some limitations in the use of Ni-Hard martensitic cast irons, in contrast to the advantages brought about by using of white-cast irons of non-ledeburitic matrix with high chromium content.

TL;DR: In this article, a detailed analysis of as-sprayed microstructures in addition to processing trends for several FeCrAIY-carbide coatings was provided. But, the analysis was limited to high-velocity oxy-fuel (HVOF) coatings and it was found that the carbides tend to breakdown during spraying producing a complex mixture of oxides and various carbides.

TL;DR: In this paper, a joint assembly of solder/IMCs/copper was prepared and experienced a thermal aging test for 50, 100, 400, and 600 hours at 150°C, and the morphology at the interface of the assembly was investigated with an optical microscope (OM) to measure the thickness of the intermetallic layer, and with secondary electron images (SEI) to evaluate the interfacial microstructure.

TL;DR: The deformation-induced microstructures and fracture appearances of Fe-Mn-Cr-N austenitic steel have been studied by using metallography, X-ray diffraction, scanning electron microscopy, and transmission electron microscope.

TL;DR: In this article, a comparative study of the hardness characteristics, mechanical properties, microstructures, and fracture mechanisms of the thermite welded rail steel joints before and after heat treatment is presented.

TL;DR: In this paper, a finite element method is used to determine the constitutive stress strain curve, expressed as a multilinear hardening law, for hard and commonly brittle isotropic materials.

TL;DR: In this article, the possibilities as well as the current limitations of off-axis electron holography at atomic dimensions are discussed, and they are illustrated at two applications of structure characterization of ϵ-NbN and YBCO-1237.

TL;DR: In this paper, the impact of high radiation fields on corrosion, hydrogen embrittlement, and corrosion fatigue in high-energy proton accelerators has been analyzed, and the potential for such degradation must be included in design and service life assessments of the materials and components.

TL;DR: In this article, a generalized grain size is determined from the slope of the size distributions, which is used to interpret the toughness properties of high strength and extra high strength (EHS) steels.

TL;DR: In this article, a shallow penetration overlay technique was successfully demonstrated to minimize cracking in irradiated 304 stainless steel that contained 10appm helium, and a model was developed that qualitatively showed the interaction of three primary and three secondary variables producing helium embrittlement cracking.

TL;DR: In this paper, the authors studied the bundling and interdigitation of the passivation thiolates in forming the directional molecular bonds in nanocrystal superlattices (NCSs) constructed by truncated octahedral Ag particles.

TL;DR: In this paper, an ultrasonic testing technique was employed to determine the volume fraction of alumina particulate reinforcement in 6061 aluminum matrix composites with nominal volume fractions of 10, 15, and 20%.

TL;DR: The Accelerator Production of Tritium (APT) Target/Blanket (T/B) system is comprised of the T/B assembly and the attendant heat-removal systems as mentioned in this paper.

TL;DR: In this paper, the influence of hot rolling conditions, cold reduction rate, and final annealing on the evolution of steel sheet textures was studied, and it was suggested that the drawability of sheets annealed after cold rolling improves if greater than conventional reduction rates are used during rolling.

TL;DR: In this paper, a simple and accurate method of determining the habit planes from the determination of beam and habit plane trace directions using Kikuchi line diffraction patterns and the measurement of the thickness of the thin foil has been developed.

TL;DR: In this paper, the shape of the stretch zone surface was analyzed based on parallax measurement theory and using digital image processing techniques, and it was concluded that the geometry of stretch zone profiles under plane strain conditions can be described by a semi-parabolic relationship.

TL;DR: In this article, a tensile test on Fe-40Al single crystals with two different vacancy concentrations was performed in both air and vacuum and it was shown that the room temperature fracture strengths are significantly increased but the elongations are decreased in both test environments at high vacancy concentration.

TL;DR: In this article, a testpiece made of AISI 1050 steel has been surface hardened successfully by electrolysis in aqueous solution, and a U.S. patent application on this new technology has been submitted in order to protect the intellectual property rights.

TL;DR: Gleeble simulation studies of the effects of welding on the microstructural change of four FeAl-based materials with Mo, Zr, C, and B additions based on light optical metallography and x-ray diffraction techniques have been undertaken as discussed by the authors.

TL;DR: In this article, a cooling water loop capable of exposing corrosion samples to an 800MeV proton beam at currents upwards of 1 mA was constructed at the A6 Target Station of the Los Alamos Neutron Science Center (LANSCE).

TL;DR: In this paper, the results of three-point bend tests were performed at 4.2K for short-beam shear determinations in the laminate materials and for shear strength in the remainder of the specimens.