Sterling,Ringwood, and Greenwood

The growing new research area being developed along the New York-New Jersey border at Sterling Forest recalls metallurgical history that was made in this same region. For it was here that ironmaking was centered from colonial days until after the Civil War. This is an important chapter to be added to historical ironmaking articles featured in earlier issues of Journal of Metals.     

Suppression of carbon monoxide formation in oxide-coated TZM molybdenum X-ray rotating anodes

Higher performance designs for rotating anode X-ray tubes have increased the average rotating anode temperature from below 1100 °C to well above 1300 °C. This temperature increase has accelerated the formation of carbon monoxide by reaction of carbon from the alloy substrate with oxygen from the emissive coating. The dominant carbon source is thought to be Mo₂C grain boundary precipitates in the TZM molybdenum alloy substrate. The dominant oxygen source is thought to be TiO in the emissive coating. Placement of a monocarbide-forming reactive layer between the alloy substrate and the emissive coating has been demonstrated to lower the thermodynamic activity of the carbon source and dramatically reduce the rate of formation of carbon monoxide.     

The Cd-Cu (Cadmium-Copper) system

This work was supported by ASM INTERNATIONAL and the Department of Energy through the Joint Program on Critical Compilation of Physical and Chemical Data coordinated through the Office of Standard Reference Data (OSRD), National Institute of Standards and Technology. Literature searched through 1987. Part of the bibliographic search provided by ASM INTERNATIONAL     

Issues in the replacement of lead-bearing solders

The use of soft solders, particularly those containing lead, dates back nearly 5,000 years. Solders similar to the materials used to seal the aqueducts of ancient Rome are now an important building block in the manufacture of high-speed computer assemblies. This history attests to the technological versatility of soft solders and, in particular, the solder alloys that contain lead. However, the health effects of prolonged exposure to lead have also been documented; measures to limit human exposure—at the work place and indirectly through the environment—are being considered. The successful introduction of lead-free solders into future electronic products will rely heavily upon their solderability, which can be evaluated by test procedures such as the meniscometer/wetting balance technique and the capillary flow test.     

An AES study of the oxidation of a 97Pb3Sn alloy

A 97Pb-3Sn alloy was oxidized at oxygen pressures below 10 mPa and temperatures from 20°C to 200°C. The reaction was monitored by Auger electron spectroscopy (AES). The oxide film formed most likely is SnO and is less than 2 nm thick. Lead is oxidized only if there is no tin at the surface. If tin can diffuse to the alloy surface sufficiently fast, lead will not be oxidized. Oxidized lead is reduced by metallic tin.     

Mechanical properties and fracture upon static tension of the high-carbon steel with different types of pearlite structure

The hardness and mechanical properties of the U10 steel (1.03 wt % C) with pearlite structures that were formed by isothermal decomposition at temperatures of 650°C (coarse-lamellar pearlite) and 500°C (fine-lamellar pearlite) as well as upon subsequent annealing of fine-lamellar pearlite at a temperature of 650°C for 10–300 min have been studied upon tensile tests. Fractures of the steel with different types of pearlite structure have been examined using scanning electron microscopy. The interrelation between the mechanical properties and the structural features and character of fracture has been analyzed for this steel with pearlite structures differing in the dispersity, morphology, and defect structure of cementite, and in the levels of solid-solution strengthening and microdistortions of the ferrite-constituent lattice.     

Enhancement of bending strength of heat-resistant steel by ion carbonitriding

The heat-resistant steel 20Kh3MVF-Sh is used for toothed gears employed in pumps of turbojet engines. In service, the working surface of the gears is subjected to intensive wear. Using gas-phase carburizing to case-harden such gears has proven to be insufficiently effective. In this work we have investigated the structure, the chemical composition, and the wear resistance of 20Kh3MVF-Sh steel after ion carbonitriding. We have obtained regression equations relating the wear resistance characteristics to the carbon and nitrogen concentration and the hardness of the diffusion layer. We have developed a combination process for ion carbonitriding which increases the wear resistance or steel 20Kh3MVF-Sh.N. É. Bauman State Technical University, Moscow. MAKB TEMP. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 9–13, June, 1994.     

Processing ceramic-matrix composites using electrophoretic deposition

A novel, cost-effective processing technique for manufacturing ceramic-matrix composites (CMCs) containing two-dimensional woven-fiber reinforcement has been developed. The technique relies on the electrophoretic deposition (EPD) of ceramic sols on/into the fiber preforms to achieve the required impregnation. The laboratory-scale results achieved thus far indicate that the processing approach offers great potential for the manufacture of high-quality, composite products with dual-component oxide matrices for high-temperature structural applications.     

Spin Extrusion - A New Partial Forming Technology based on 7 NC-Axes Machining

Hollow shape component approaches, applied to shafts and similar workpieces, represent a major potential for ground-breaking innovations in lightweight engineering and safety designs. Among suitable forming technologies, spin extrusion is a pioneering and particularly flexible hollow-shaping technique. All outside form elements, straight or stepped cylinders, cones or spherical rotation elements emerge just from the kinematics of tools. The inside hollow shapes, as e.g. circular cross-sections, shaft to collar connections such as spherical triangles, polygons, splines or dovetail forms are manufactured with a shaping mandrel. Spin extrusion can be applied first and foremost at dimensions that are unattainable with other techniques. The application includes hollow shafts, thick-walled cups and semi-finished tubular products that are not to be found in off-the-shelf cross-sections. In these cases the possibility for using of massive bars is connected with very high price advantages. Furthermore material-saving machining is attracting special attention for high-grade materials.The paper characterizes substantial steps of process analysis and the appliance of a new, derived from the bound method, numerical simulation method for spin extrusion process. Holistic process analysis is the prime factor for process capability. The specific application of the developed special methods of simulation, the accumulation of process data and the integrating into the Computer numerical control of spin extrusion machine is a precondition guaranteeing high-quality assurance.     

The treatment influence on the electric strength and conductivity of fibroin

The influence of thermal treatment and liquid nitrogen treatment of cocoons on the electric properties of natural silk fibroin has been studied. It is found that, at the cocoon treatment by liquid nitrogen, the ratio of the amorphous and crystalline parts of the fibroin is preserved and the concentration of submicrocracks in them changes to a lesser extent than at treatment by heated air and a UHF field. The increase of the degree of crystallinity in the polymers leads to a certain increase of their breakdown voltage.