Showing papers by "Kaiser Aluminum published in 1982"

Rapidly deployed assault vehicle surfacing or trackway system

Abstract: A transportable modular assault vehicle water egress and bridge access/egress surfacing or trackway system wherein a plurality of rectangularly shaped planks or sections are joined by flexible hinge members and can be folded accordion fashion and suspended in a container for storing, transporting and rapidly deploying to provide a surfacing upon the shores or banks of bodies of water for the access and egress of military vehicles into and out of bodies of water during military operations.

Molten metal level control in continuous casting

Abstract: This invention is directed to the process and system for controlling the level of molten metal in a plurality of vertically oriented, continuous or semicontinuous casting units, particularly electromagnetic casting units. The flows of molten metal to the individual casting units are adjusted automatically in response to a control set point signal from a master controller in order to maintain essentially the same molten metal level in all of the casting units. Improved startup and termination procedures are also given.

Improved self-grinding valve

Abstract: An improved, motorized Lunkenheimer valve is provided having two independently actuated drive means for operating the valve, one of which moves the valve stem and disc longitudinally along the axis of the stem and the other of which rotates the stem and disc about the longitudinal axis of the stem. The two drive means can be operated concurrently to effect more rapid opening or closing, and countercurrently to provide a continuous grinding operation when the valve is in the closed position.

Aluminum Penetration and Fracture of Titanium Diboride

Abstract: Relatively porous titanium diboride (=96% dense) is penetrated with aluminum metal when used as a cathode in aluminum reduction cells operating at 970°C. Metal penetration changes the predominant fracture mode from trans-granular to inter granular, and has potentially important ramifications on mechanical properties.

The Effect of Some Operating Variables on Flow in Aluminum Reduction Cells

Abstract: The significant effects of current distribution and magnetic field on reduction cell operation have been recognized for many years. The current distribution and magnetic field are determined partly by the design of the cell and partly by operating variables such as anode current distribution, condition of the cathode bottom, and the influence of adjacent cells. Recent work has been done on design considerations for stable cell operation but very little on cell operation under conditions removed from ideal.

Decomposition voltage for the electrolysis of alumina at low temperatures

Abstract: The apparent decomposition voltage for the electrolysis of alumina in an equimolar Na3AlF6-Li3AlF6 electrolyte was measured over a temperature range of 800 to 1000° C by the extrapolation of voltagecurrent plots to zero current. Temperature coefficients of −1.9 and −2.4 mV° C−1 were determined for conditions of variable alumina activity (constant concentration) and unit activity (saturated), respectively. The overvoltage contribution to the temperature dependency was estimated to be about −1.6mV° C−1 (versus a −0.6 mV° C−1 dependency for the reversible decomposition voltage). Reduced alumina solubility at low temperatures also appeared to increase the overvoltage, but was of secondary importance.

Calcination control system

Abstract: Nuclear magnetic resonance (nmr) is employed for the control of heat-input or feed rate of calcination and/or drying facilities. The residual volatile material content of the heat-treated material is monitored by nmr and the results obtained from the monitoring are employed to adjust the heat-input or feed rate to avoid overdrying or calcining of the heat-treated material. A computer, such as a microprocessor, may be utilized in combination with the nmr apparatus to provide instantaneous process control.

Factors Influencing the Fracture Toughness of High Strength Aluminum Alloys

Abstract: Variations in fracture toughness were measured through the thickness of rolled plates of a range of heat-treated aluminum alloys, including 2024, 2124, 7075, 7475 and 7050. The reasons for these variations were examined in detail in 7475 and 7050, and explanations are proposed. Fracture mechanisms were studied, and it is concluded that toughness is influenced strongly by eutectic phases, even in the high purity alloys.

Kaiser Aluminum Plant Implementation of Electromagnetic Casting

Abstract: Kaiser Aluminum has installed its first electromagnetic casting station at its Trentwood Works. The five-ingot station casts 20 in. × 43 in. ingots of 5182 aluminum alloy for can lid stock. The successful implementation of the new process is attributed in large measure to careful testing, organization, and training. EM casting requirements are generally more stringent than conventional casting, particularly with respect to station alignment, cooling water quality, and metal inclusions. Advantages of the process include elimination of scalping, as well as numerous casting and roling mill economies, such as a low ingot inventory and shorter homogenization times. The surfaces of electromagnetic ingots are smooth and generally free of defects. All of Kaiser’s can lid stock customers are currently using electromagnetically cast alloy 5182.

A "New" Crosslinking Process for Extruded Dielectric Cable

Abstract: Commercial processes used to make extruded crosslinked dielectric cable and factors affecting cable quality are briefly reviewed. In most processes, the cable is heated (cured) and cooled from the outside and productivity is controlled by heat conduction through the dielectric. In laboratory experiments described here, the dielectric is simultaneously cured from the inside by inductively heating the cable conductor and from the outside using steam. This technique, termed INPRO, increases productivity and improves cable quality (residual peroxide, visual halo, microvoids, cure state, and heat distortion resistance). Computer calculations indicate that similar benefits might be obtained commercially.