Showing papers by "Cabot Corporation published in 1978"

Effect of Carbon Black on Dynamic Properties of Rubber Vulcanizates

Abstract: The term dynamic properties as applied to elastomers refers to the response to periodic or transient forces which do not cause failure or appreciable fatigue (permanent change of properties) during the investigation. Generally this is limited to vulcanizates subjected to deformations not exceeding about 25%; and generally the dynamic properties are measured after several cycles or (in a transient experiment such as resilience) after several preconditioning transients, so that the Mullins effect or difference between first and second strain cycles is not of consequence. Thus, dynamic properties represent the viscoelastic properties of vulcanizates at deformations below about 25%, after reaching a pseudo-equilibrium state. The dynamic properties of rubber are altered tremendously by the addition of a filler. The scope of this article is restricted to the dynamic properties of rubber vulcanizates with carbon black as a filler. The effect covered in this article are important in designing rubber comp...

Steady state segregation and heat flow in ESR

Abstract: A combined theoretical and experimental study of steady-state heat flow and segregation in ESR is presented. The segregation model permits prediction of pressure gradients, hence, interdendritic flow velocities responsible for macrosegregation in the “mushy≓ zone of axisymmetric ESR ingots. The heat flow model considers the solidus isotherm as a moving boundary. The relationships between power and slag temperature as well as power and heat transfer coefficient are experimentally measured and included in the heat balance equation for the slag. Experiments on both a low-temperature simulated ESR apparatus and on a 200 mm diam ESR ingot mold verify both models.

Influence of Carbon Black Surface Properties and Morphology on Hysteresis of Rubber Vulcanizates

Abstract: A linear relation is found between tan δ and a loading-interfacial-area parameter, ϕψ, for NR vulcanisates with six untreated carbon blacks at several loadings. In IIR, a better linear rel...

Sintered high performance metal powder alloy

Abstract: Articles of high performance chromium-containing cobalt-base alloys sintered from powder contain boron in amounts between about 0.1 and 1.0%. The addition of boron widens the range of sintering temperatures sufficiently to make possible commercial production of articles of compositions which otherwise are difficult or impossible to sinter.

Influence of Carbon Black on Processability of Rubber Stocks III. Extensional Viscosity

Abstract: A new instrument for measurement of extensional viscosity was designed and employed in the evaluation of SBR compounds containing carbon black and other non-black fillers. It was shown that carbon black filled rubbers generally do not reach steady-state viscosity ; the stress continues to increase with increasing strain up to the point of rupture, due to rapid orientation of molecular chains during extensional flow. The data was evaluated in terms of the Denn-Marrucci equation, and the effect of carbon black on the two adjustable parameters was found. It was found that higher carbon black loading or structure increases only the viscosity coefficient, i.e., it changes the relative level of the flow curve without changing its shape. On the other hand, an increase in surface area increases both the viscosity coefficient and the relaxation time, i.e., it increases the upward curvature of the flow curve. A very good correlation was observed between Mooney viscosity values and calculated viscosity coef...

Oxidation resistant asphalt compositions

Abstract: Disclosed herein are carbon black-containing asphalt compositions having improved properties of resistance to thermal and actinic oxidation.

Alloys resistant to localized corrosion, hydrogen sulfide stress cracking and stress corrosion cracking

Abstract: An alloy and a metal product characterized by resistance to localized corrosion, hydrogen sulfide stress cracking (hydrogen embrittlement) and stress corrosion cracking at temperatures up to about 200° C. consisting essentially of nickel 40-65%, cobalt 0-5%, chromium 10-20%, molybdenum 12-18%, iron 10-20%, tungsten up to 5%, carbon 0-0.1% manganese up to 3%, vanadium up to 1% and silicon up to 0.2%. The alloy resistance is maintained when it is cold worked over 20%.

Corrosion-resistant nickel alloy

Abstract: A nickel-base alloy that is corrosion resistant to hydrogen, sulfide and chloride stress cracking is provided consisting essentially of about 17 to 23% chromium, 8 to 10% molybdenum, 15 to 22% iron, limited contents of cobalt, silicon and manganese, 0.030% maximum carbon and the balance nickel and incidental impurities. The alloy is eminently suited for use as components in so-called "sour-gas" well operations.

Methods of hard facing

Abstract: A method of forming a hard surfacing on a metal article is provided based upon forming a weld wire with a diffusion layer containing boron and depositing the wire on the surface to be hard surfaced by means of an electric arc to form a substantially uniform boron containing alloy weldment composition.

Wear-resistant nickel-base alloy

Abstract: Disclosed is a nickel-base alloy typically containing in weight percent, about 2.7 carbon, about 10.5 cobalt, about 27 chromium, about 23 iron, about 10 molybdenum plus tungsten, up to 2.5 maximum tungsten, and the balance nickel and incidental impurities. The alloy is especially suited for use as wear-resistant articles and may be produced in various forms, such as castings, metal powder, tube rod and/or wire and wrought articles. The alloy composition is particularly designed to conserve cobalt and tungsten and yet provide wear-resistant articles comparable to cobalt-base alloys with high tungsten contents.

Methods and apparatus for making cast hollows

Abstract: TITLE METHODS AND APPARATUS FOR MAKING CAST HOLLOWS ABSTRACT A method and apparatus are provided for forming hollow superalloy ingots by melting a molten superalloy electrode by ESR techniques into a molten slag held in a generally cylindrical mold having an axially movable mandrel until the molten metal is adjacent the level of but not over the top of the mandrel, cooling the metal sufficiently to form supporting external and internal walls, moving the mand-rel vertically relative to the cooled metal, continuing to melt metal into said slag while moving the mandrel at a rate such that the molten metal remains at a substantially constant level adjacent the top of the mandrel and cooling the formed hollow ingot.

Method of aspiration casting

Abstract: A method for forming metal articles, such as rods and tubes by aspiration casting is provided in which a hollow frangible mold, such as a glass tube, is immersed at one end in a molten metal bath, a vacuum is applied to the other end controlled with respect to temperature of the molten metal so as to substantially fill the mold with a minimum of turbulence, the filled mold is withdrawn from the metal and the frangible mold is shattered to remove it from the metal article formed within.

Vacuum casting heads and clamps

Abstract: A casting head and clamp arrangement for vacuum aspiration casting of metal rods in glass tubes is provided having a casting head with a generally vertical vacuum passage, a removable fluid pressure chuck in the lower end of said vacuum passage adapted to receive and hold the end of a glass tube, said chuck including a pair of spaced annular support discs, spaced elongate members connecting said support discs, sleeve members having an internal dia-meter larger than a glass tube to be held fixed on each of support disc annulus and protecting beyond said discs between the elongate members, an elastomer tube fixed at its opposite ends to the sleeve members and having an internal diameter larger than the diameter of the glass tube to be held and fluid pressure means acting between said discs to cause the elastomer tube to decrease in effective internal diameter under pressure to engage and hold the glass tube ends and to release the tube ends when the fluid pressure is released.