Browsing by Author "Clifton, T. E."

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    The design and construction of a weld heat-affected zone simulator
    (College of Aeronautics, 1968-02) Clifton, T. E.; George, M. J.
    Investigation of the structure and properties of the heat-affected zones in welded joints is usually limited by their small size and their complexity. One method of overcoming this problem is to simulate the structure at a particular point in the heat-affected zone in a specimen of larger size by imposing on it the thermal cycle sustained at that point. The equipment described in this note uses a.c. resistance heating and water cooling to impose thermal cycles on 2.5" x O.W' x O.W' specimens, the thermal cycle being chosen by adjustment of a bank of variable resistors to construct a voltage analogue. Control of specimen temperature is achieved using a thyristor and two ignitrons to control the input at 44ov. to a welding transformer. Feedback is applied from a thermocouple welded to the specimen hot-zone. The equipment has been shown to produce the desired thermal cycles in a reproducible manner.
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    The development and evaluation of an ultrasonic fatigue unit
    (College of Aeronautics, 1963-03) Clifton, T. E.
    A fatigue test apparatus operating at 20 kc/s is described. The unit is based on a standard magnetostrictive drive system as used in high energy stresswave generators. An automatic counting device has been developed and incorporated in the final equipment, resulting in improvements in accuracy and reproducibility of results. Some typical results of tests on aluminium alloys are presented.
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    High temperature creep properties of Mo T.Z.M. alloy
    (College of Aeronautics, 1965-10) Clifton, T. E.; Cook, P.
    Introduction This memorandum reports a series of experiments to determine some tensile creep properties of Mo T.Z.M. alloy at elevated temperatures in the range 1200°C to 1800°C, the material being in sheet form. A subsequent memorandum will report some creep properties of W-Th02 alloy.
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    High temperature creep properties of W-ThO2 alloy
    (College of Aeronautics, 1966-03) Clifton, T. E.; Cook, P.
    Introduction This memorandum reports a series of experiments to determine some tensile creep properties of W.Th02 alloy at elevated temperatures.
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    Push-pull fatigue properties of wires in an iridium - 5% tungsten alloy
    (College of Aeronautics, 1965-11) Clifton, T. E.; Whitbread, R. C.
    Introduction This memorandum reports a series of tests to determine the fatigue properties of an iridium - 5% tungsten alloy at 600°c and 700°C. A previous memorandum, Memo. Mat. 61, reports the fatigue properties at room temperature of the same alloy.
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    Stress redistribution due to creep in nimonic 90 ministry of aviation contract no. PD/28/021 report for the period January 1964 - June 1965: part 1
    (College of Aeronautics, 1965-09) Younger, A.; Clifton, T. E.
    The period covered by this report has been devoted to the design, construction development and calibration of a special apparatus to simulate the stress redistribution conditions occurring during the creep of a cooled turbine blade. The experimental assembly consists of two creep machines, each operating at a different temperature, so controlled that a load is shared between them. maintaining equal creep strains (and in consequence equal creep rates) in each specimen. The stress in each specimen and the creep strain of the pair are automatically measured and recorded by a specially developed unit. Some preliminary results on an aluminium alloy are presented.
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    Stress redistribution due to creep in nimonic 90 ministry of aviation contract no. PD/28/021 report for the period June, 1965 to July, 1966: part 2
    (College of Aeronautics, 1966-08) Clifton, T. E.
    Part I of this report, dated September 1965, deals mainly with the design and construction of the special apparatus to simulate the stress redistribution occurring during the creep of a cooled turbine blade. It reported some preliminary experiments using aluminium alloy test specimens. During the past year, the period covered by this report, a series of experiments have been completed using specimens machined from nimonic 90 alloy. Experience gained in operating the apparatus, have resulted in several modifications both to the apparatus and the associated instrumentation. These are detailed within this report.