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Fatigue Resistance of Duralumin

Description: Where, in the following report, mention is made of fatigue, it always refers to the weakening of the material produced by rapidly changing stresses below the point of elasticity. The alternating stress was obtained by a test bar which was held at one end and subjected to rotation. Most of the tests were conducted on connecting rods.
Date: September 1922
Partner: UNT Libraries Government Documents Department

Duralumin and Its Corrosion

Description: The types of corrosion and factors of corrosion of duralumin are investigated. Salt water is the most common of the corroding media with which designers have to contend in using duralumin in aircraft and ships.
Date: April 1927
Creator: Nelson, Wm.
Partner: UNT Libraries Government Documents Department

Duralumin - Defects and Failures

Description: It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.
Date: December 1927
Creator: Nelson, Wm.
Partner: UNT Libraries Government Documents Department

Duralumin, Its Properties and Uses

Description: A historical sketch of duralumin is presented, especially in regards to its manufacture by various countries. The properties of duralumin are discussed and strength characteristics listed. Increasing the hardness of duralumin by tempering is discussed as well as the uses of the metal.
Date: October 1924
Creator: Beck, R.
Partner: UNT Libraries Government Documents Department

Duralumin Welding

Description: Gas and electric welding of duralumin are discussed. Some of the elements that go into determining a successful weld and inspecting for faults are also described.
Date: February 1927
Creator: Nelson, Wm.
Partner: UNT Libraries Government Documents Department

The Heat Treatment of Duralumin

Description: When certain light aluminum alloys are heat-treated, quenched and aged, there is considerable improvement in their tensile properties. This paper presents different methods of accomplishing these heat treatments.
Date: March 1927
Creator: Nelson, Wm.
Partner: UNT Libraries Government Documents Department

The Compressive Strength of Duralumin Columns of Equal Angle Section

Description: "This report presents a chart giving the compressive strength of duralumin columns of equal angle section. The data used in the construction of the chart were obtained from various published sources and were correlated with theory in the range where secondary failure occurred. Appendices are included giving excerpts from Army and Navy specifications for duralumin and approximate formulas for the properties of the equal angle section" (p. 1).
Date: March 1932
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Strength Tests on Thin-Walled Duralumin Cylinders in Torsion

Description: This report is the first of a series presenting the results of strength tests on thin-walled cylinders and truncated cones of circular and elliptical section; it comprises the results obtained to date from torsion (pure shear) tests on 65 thin-walled duralumin cylinders of circular section with ends clamped to rigid bulkheads. The effect of variations in the length/radius and radius/thickness ratios on the type of failure is indicated, and a semi-empirical equation for the shearing stress at maximum load is given.
Date: August 1932
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Strength Tests of Thin-Walled Duralumin Cylinders in Compression

Description: "This report is the second of a series presenting the results of strength tests of thin-walled duralumin cylinders and truncated cones of circular and elliptic section. It contains the results obtained from compression tests on 45 thin-walled duralumin cylinders of circular section with ends clamped to rigid bulkheads. In addition to the tests on duralumin cylinders, there are included the results of numerous tests on rubber, celluloid, steel, and brass cylinders obtained from various sources" (p. 585).
Date: June 10, 1933
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Strength Tests of Thin-Walled Duralumin Cylinders in Pure Bending

Description: "This report is the third of a series presenting the results of strengths tests on thin-walled cylinders and truncated cones of circular and elliptic section; it includes the results obtained from pure bending tests on 58 thin-walled duralumin cylinders of circular section with ends clamped to rigid bulkheads. The tests show that the stress on the extreme fiber at failure as calculated by the ordinary theory of bending is from 30 to 80 percent greater than the compressive stress at failure for thin-walled cylinders in compression. The tests also show that length/radius ratio has no consistent effect upon the bending strength and that the size of the wrinkles that form on the compression half of a cylinder in bending is approximately equal to the size of the wrinkles that form in the complete circumference of a cylinder of the same dimensions in compression" (p. 1).
Date: December 1933
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department

Strength Tests of Thin-Walled Duralumin Cylinders in Combined Transverse Shear and Bending

Description: "This report is the fourth of a series presenting the results of strength tests on thin-walled cylinders and truncated cones of circular and elliptic section; it includes the results on 100 thin-walled Duralumin cylinders of circular section with ends clamped to rigid bulkheads. The tests show that as the ratio of moment to shear varies from small to large values the failure changes from a shear to a bending type. In the report a chart is presented that shows the corresponding changes in strength" (p. 1).
Date: April 1935
Creator: Lundquiest, Eugene E.
Partner: UNT Libraries Government Documents Department

Tests on Riveted Joints in Sheet Duralumin

Description: In making tension tests, the slippage of the joints was noted at three points across each joint. In addition, stress strain curves were obtained for plain tension specimens, and a chemical analysis was made of the sheet.
Date: November 1923
Creator: Rettew, H. F. & Thumin, G.
Partner: UNT Libraries Government Documents Department

Corrosion Embrittlement of Duralumin 1: Practical Aspects of the Problem

Description: Since aircraft design is tending toward all-metal construction, the strong heat-treatable light aluminum alloy, duralumin (a generic name for a class of heat-treatable alloys containing Cu, Mg, Mn, and Si), is finding increasing application. Doubt has been expressed concerning the reliability and permanence of these materials. Information is given on the effect of corrosion on the tensile properties of 14-gauge sheet duralumin, heat treated by quenching in hot water after being heated for 15 minutes in a fused nitrate bath at 500 to 510 C. Intercrystalline corrosion and practical aspects of intercrystalline embrittlement are discussed with respect to duralumin.
Date: April 1928
Creator: Rawdon, Henry S.
Partner: UNT Libraries Government Documents Department

Corrosion Embrittlement of Duralumin 3: Effect of the Previous Treatment of Sheet Material on the Susceptibility to This Type of Corrosion

Description: As a result of testing, it was determined that control of the rate of quenching and the avoidance of accelerated aging by heating are the only means of modifying duralumin itself so as to minimize the intercrystalline form of corrosive attack. It is so simple a means that it should be adopted even though it may not completely prevent, but only reduce, this form of corrosive attack. By so doing, the need for protection of the surface is less urgent.
Date: April 1928
Creator: Rawdon, Henry S.
Partner: UNT Libraries Government Documents Department

Recent Developments in Light Alloys

Description: This report is intended to cover the progress that has been made in both the manufacture and utility of light alloys in the United States since the first part of 1919. Duralumin is extensively discussed both as to manufacture and durability.
Date: November 1920
Creator: Woodward, R. W.
Partner: UNT Libraries Government Documents Department

The Behavior Under Shearing Stress of Duralumin Strip With Round, Flanged Holes

Description: "This report presents the results of an investigation to determine the behavior of dural strip with flanged holes in the center when subjected to shear stresses. They buckle under a certain load just as a flat sheet. There is one optimum hole spacing and a corresponding buckling load in shear for each sheet width, sheet thickness, and flange form. Comparison with non-flanged sheets revealed a marked increase of buckling load in shear due to the flanging and a slightly greater displacement" (p. 1).
Date: October 1934
Creator: Schüssler, Karl
Partner: UNT Libraries Government Documents Department

Corrosion Embrittlement of Duralumin 2: Accelerated Corrosion Tests and the Behavior of High-Strength Aluminum Alloys of Different Compositions

Description: The permanence, with respect to corrosion, of light aluminum alloy sheets of the duralumin type, that is, heat-treatable alloys containing Cu, Mg, Mn, and Si is discussed. Alloys of this type are subject to surface corrosion and corrosion of the interior by intercrystalline paths. Results are given of accelerated corrosion tests, tensile tests, the effect on corrosion of various alloying elements and heat treatments, electrical resistance measurements, and X-ray examinations.
Date: April 1928
Creator: Rawdon, Henry S.
Partner: UNT Libraries Government Documents Department

Corrosion Embrittlement of Duralumin 4: The Use of Protective Coatings

Description: Although the corrosion resistance of sheet duralumin can be greatly improved by suitable heat treatment, protection of the surface is still necessary if long life under varied service conditions is to be insured. The coatings used for this purpose may be grouped into three classes: the varnish type of coating, the oxide type produced by a chemical treatment of the surface, and metallic coatings, of which aluminum appears to be the most promising. Since the necessary weather exposure tests are not complete, some of the conclusions regarding the value of various surface coatings are necessarily tentative.
Date: April 1928
Creator: Rawdon, Henry S.
Partner: UNT Libraries Government Documents Department

Corrosion Embrittlement of Duralumin 6: The Effect of Corrosion Accompanied by Stress on the Tensile Properties of Sheet Duralumin

Description: The effect of corrosion on the tensile properties of duralumin while stressed is shown in graphical form. According to the test results, duralumin sheet, coated with aluminum, maintains its initial properties unimpaired for corrosion periods as long as 60 days with an applied tensile stress as high as 20,000 lb/sq.in., which is approximately one-half the stress corresponding to the yield point as defined here. In these tests, that material which had been heat-treated by being quenched in cold water, though far inferior to similar material having the aluminum coating, was superior to the sheet material which was heat treated by being quenched in hot water.
Date: May 1929
Creator: Rawdon, Henry S.
Partner: UNT Libraries Government Documents Department

Duralumin

Description: Various properties of duralumin as used in aircraft construction are discussed, including the effects of temperature, working, tempering, and strength.
Date: July 1920
Creator: Unger, E. & Schmidt, E.
Partner: UNT Libraries Government Documents Department

Corrosion Embrittlement of Duralumin 5: Results of Weather-Exposure Tests

Description: In a series of weather exposure tests of sheet duralumin, upon which accelerated corrosion tests in the laboratory by the wet-and-dry corrosion method in a sodium chloride solution has already been carried out, a close parallelism between the results of the two kinds of tests was found to exist. The exposure tests showed that the lack of permanence of sheet duralumin is largely, if not entirely, due to corrosion. A corrosion attack of an intercrystalline nature is very largely responsible for the degree of embrittlement produced.
Date: February 1929
Creator: Rawdon, Henry S.
Partner: UNT Libraries Government Documents Department

A STUDY OF THE TISSUE RESPONSE TO STERILE DEPOSITS OF PARTICULATE MATERIAL

Description: Thirty-seven sterile materials of common construction usage, common lubricants, and samples of wearing apparel were injected as finely divided particles into the subcutaneous soft tissues of guinea pigs, each in six different sites. At intervals of 3, 7, 14, 21, 30, 65, or 90 days, an inoculation site of each material was excised, in toto, fixed, and examined microscopically. In addition, ten selected materials were injected into the liver and spleen and deposited on the omentum and mesentery of four guinea pigs for each material type. At intervals of 7, 14, 21, and 30 days, one of each group of four animals was sacrificed and a block of tissue containing the inoculum was removed from the tissues and organs, fixed, and examined histologically. The majority of materials induced only a mild and delayed inflammatory response followed by encapsulation at the end of 14 days and a relatively inert fibrous nodule produced by the 2lst or 30th day. Copper particles incited a marked inflammatory response with abscess formation which persisted until the 90th day, although showing signs of subsiding at this time. Cudmium lesions were characterized by a peculiar zone of necrosis about the particle aggregate which persisted until the 60th day. Duraluminum of one type incited a pseudoneoplastic fibrous response. Axle grease, in the early stages, induced one of the most intense acute inflummations, in contrast to that produced by motor oil and ordinary lubricating grease, but the process had subsided and was fibrosed by the end of 30 days. (auth)
Date: October 1, 1957
Creator: Chiffelle, T.L.; Sherping, F.; Goldizen, V.C. & White, C.S.
Partner: UNT Libraries Government Documents Department