Aluminum Company of America

Douglas A Granger

Elwin L Rooy

James R Weaver

Raymond T Richter

Gerald R Petrey

H Gray Reavis, Jr

Ho Yu

William G Truckner

Michael M Kersker

Martin P Jones

H Gray Reravis, Jr

Lithoplate and method for making same

A non-destructive method for determining the presence of anisotropic structures in the interior of an as-formed metal. The method includes the steps of (a) attaching an ultrasonic transducer to the metal item prior to working the metal; (b) energizing the transducer to generate shear ultrasonic waves capable of penetrating the metal item; (c) measuring the time of flight of the shear ultrasonic waves through the metal item; (d) rotating the transducer approximately 90.degree.; (e) repeating step (c); and determining the difference between steps (c) and (e) to determine the presence of anisotropic structures in the interior of the metal item.

Method of determining the presence of anisotropic structures in the

An improved method of making a lithoplate from a 5XXX type alloy which includes controlling the composition and casting practices to eliminate forming a pine tree metal structure in an ingot used for rolling a workpiece to be made into lithoplate. The method also includes homogenizing and hot rolling the ingot at a controlled initial temperature to produce a desired grain and metal microstructure in the sheet rolled from the ingot which is suited for providing a surface having substantially uniform and evenly distributed craters produced by an electrochemical method of graining.

Method for making lithoplate

Structural streaking defects in anodized aluminum architectural sheet products are substantially reduced or eliminated in 1XXX and 5XXX type aluminum alloys by including therein 0.01 to 0.08% of chromium or manganese, preferably both. It is preferred to combine such with continuously casting the ingot under high chill rate conditions such as employing low liquid metal head within the direct chill mold.

Architectural product

A process and an apparatus are disclosed for reducing macrosegregation adjacent to a longitudinal centerline of a solidified cast body. Such cast bodies are preferably large size aluminum alloy ingots made in a continuous casting mold. The ingot is formed from a pool of molten metal having flow currents present therein. The flow currents tend to detach the tips of dendrites growing around the edge of the liquid pool and transport them to the center of the ingot. These detached dendrites, which are lean in eutectic elements, cause negative macrosegregation of the cast ingot. The process includes the step of weakening the magnitude of the flow currents within the liquid pool by placing a mechanical damper therein. The mechanical damper reduces shear acting on the dendrites and minimizes detachment and transport of dendrite particles to the center of the solidified body. The magnitude of the flow currents can also be reduced by increasing the metal head of the liquid pool or by reducing the kinetic energy of newly added molten metal. The apparatus claims a mechanical damper consisting of two or more parallel plates or concentric rings which extensively increases the surface area within the liquid pool. The plates or rings are spaced apart so as to provide flow passages for the molten metal which encourages laminar flow and tends to reduce turbulence within the pool.

Process and apparatus for reducing macrosegregation adjacent to a

An aluminum alloy consisting essentially of about the following percentages of materials:

Growing community of inventors

Murrysville, PA, United States of America

Douglas A Granger