Showing papers by "SF Etris published in 1974"
TL;DR: In this article, the authors investigated the low temperature ductility of several vacuummelted, 25 percent chromium, ferritic stainless steels containing between 300 and 900 ppm total interstitials (C + N + O) using impact and tensile tests.
Abstract: The low temperature ductility of several vacuummelted, 25 percent chromium, ferritic stainless steels containing between 300 and 900 ppm total interstitials (C + N + O) has been investigated in the water-quenched condition using impact and tensile tests. In the low interstitial content alloys, the ductile-brittle transition temperature was markedly influenced by changes in interstitial content and grain size, whereas for the high interstitial contents such changes were not as significant. Tensile tests on the same alloys indicated that the yield stress was not sensitive to variations in either interstitial content or grain size. It is shown that increasing the interstitial content in these high chromium ferritic steels effects an increase in the amount of second phase present, particularly at the grain boundaries. Such particles enhance cleavage fracture by reducing the surface energy. It is observed that the second phase content is a single valued function of the ductile-brittle transition temperature.
21 citations
TL;DR: The brittle-to-ductile recovery temperature (B2D) was defined in this article, where the ductility was recovered at 695°F (368°C), the so-called B2D recovery temperature.
Abstract: Pure lead soldered to the gage section of 200-ksi (1379-MPa) 4145 steel tensile specimens tested at temperatures ranging from room temperature to 700°F (371°C) exhibit a severe loss in ductility between 400 and 680°F (204 and 360°C). The ductility, as measured by reduction of area, recovered at 695°F (368°C), the so-called brittle-to-ductile recovery temperature. This recovery temperature was shifted to higher temperatures in a sensitive manner by relatively small amounts of either tin or antimony added to alloy the externally applied lead.
21 citations
TL;DR: In this paper, the effect of temperature and density on the thermal conductivity of cellulosic insulations has been studied together with a limited investigation on moisture effects, which indicates that the raw materials and their processing can have a significant influence on the heat transmission properties.
Abstract: Measurements of heat transmission in a number of different loose fill cellulosic insulations have been made by heat flow meter and guarded hot plate methods. Effect of temperature and density have been studied together with a limited investigation on moisture effects. Variations of up to 18 percent occur in the same nominal materials from different sources. This fact indicates that the raw materials and their processing can have a significant influence on the heat transmission properties. For the optimum density range of 35 to 40 kg/m3 and above, the different materials have a very similar temperature coefficient of thermal conductivity. Lower density materials have a significant radiation contribution to their total heat transmission characteristics.
21 citations
TL;DR: In this paper, the tensile behavior of tin-lead solder has been determined as a function of various solidification parameters and the results indicate that at solidification rates observed in solder joints the solder alloy possesses superplastic properties similar to those previously observed in deformed and aged alloys.
Abstract: The tensile behavior of a near eutectic tin-lead solder has been determined as a function of various solidification parameters. The results indicate that at solidification rates observed in solder joints the solder alloy possesses superplastic properties similar to those previously observed in deformed and aged alloys.
18 citations
TL;DR: In this article, the tensile stress-relaxation behavior of several 0.255mm diameter (30 AWG) high-strength, high-conductivity copper and copper alloy conductors were studied in the temperature range 23°C to 149°C (73°F to 300°F) for a time period extending to 10,000 h.
Abstract: The ability of pressure-type electrical connections to remain stable and reliable over long periods of time depends in large measure on the stress-relaxation characteristics of the conductor and the connector material. For applications such as the miniaturized solderless wrapped connection, traditionally made with copper No. C110 (ETP copper), the relaxation of the conductor is far greater than that which occurs in the terminal; hence, for this type of termination the behavior of the conductor material governs the stability of the termination. Miniaturization of telephone equipment and the associated increase in ambient operating temperatures requires improved conductor materials which, in addition to having adequate tensile strength, ductility, and high electrical conductivity, are able to resist stress relaxation at these higher temperatures. Based on these considerations the tensile stress-relaxation behavior of several 0.255-mm diameter (30 AWG) high-strength, high-conductivity copper and copper alloy conductors were studied in the temperature range 23°C to 149°C (73°F to 300°F) for a time period extending to 10,000 h. Stress-temperature-time relationships are shown to follow Arrhenius behavior, thus permitting a choice of realistic accelerated aging test requirements for connections made with these copper alloy conductors. Since high-speed production of these conductor materials possibly may require in-line strand annealing procedures, a comparison of the stress-relaxation behavior of commercially processed strand annealed samples with that of laboratory processed batch annealed material, as well as a comparison of the effects of gage size on stress relaxation [0.511-mm (24-AWG) diameter versus 0.255-mm (30-AWG) diameter wires] was included in this study. Since no significant size effects were observed, available stress-relaxation data on a number of 0.511-mm (24-AWG) diameter high-strength, high-conductivity copper and copper alloy conductor materials are also included for convenient reference.
10 citations
TL;DR: In this article, the effects of several factors which influence the magnitude and variation with life of fatigue notch factor (Kf) are discussed in the presence of stress raisers, such as crack propagation duration and theoretical stress concentration factor.
Abstract: The effects of several factors which influence the magnitude and variation with life of fatigue notch factor (Kf) are discussed in this paper. Plasticity at the roots of stress raisers is known to have the most dominant influence on the variation of Kf when a failure criterion of fatigue crack initiation is employed. When a failure criterion other than cycles to crack initiation is employed, the duration of crack propagation becomes a significant factor in the determination of magnitude and variation of Kf. The duration of crack propagation is viewed as a primary influence on the magnitude of Kf since the increase in propagation duration with increasing theoretical stress concentration factor (Kf) accounts in part for the decrease in notch sensitivity. New evidence is given to the influence of the above two factors on Kf and an attempt is made to add to the understanding of fatigue process in notched components.
9 citations
TL;DR: In this article, a noncontacting optical transducer was used for the measurement of flexural resonant frequencies and normal mode shapes of a cantilever beam, gripped at the fixed end by a vise, compared with the Bernoulli-Euler and Timoshenko beam theories.
Abstract: The application of a noncontacting optical transducer for the measurement of flexural resonant frequencies and normal mode shapes of a cantilever beam is described. Results on the resonant frequencies of cantilever beams, gripped at the fixed end by a vise, are compared with the Bernoulli-Euler and Timoshenko beam theories. Although the mode shapes agree well with the theories, there are large discrepancies between the experimental variation of resonant frequency with inverse slenderness ratio and that predicted by the theories. These discrepancies are attributed to imperfect clamping. It is concluded that for accurate Young's modulus calculations from the measured resonant frequencies of cantilever beams, tests must be restricted to long slender beams. For beams which cannot be fabricated to meet this criterion, an empirical method is presented which yields Young's modulus to within ±3 percent on the specimens tested. For increased accuracy the free-free reasonant beam method should be used.
8 citations
TL;DR: The magnetomechanical damping properties of an AISI 403 stainless steel, tested in torsion, were found to behave differently under the action of applied static axial and torsional stresses as discussed by the authors.
Abstract: The magnetomechanical damping properties of an AISI 403 stainless steel, tested in torsion, were found to behave differently under the action of applied static axial and torsional stresses. A constant torsional stress decreased the damping peak, broadened it, and shifted it to higher stresses. In contrast, a static axial load shifted the peak to lower log decrement values but did not change the peak damping stress. These observations are explained in terms of the effect of the static stresses on the shape of the stress-strain hysteresis loop.
7 citations
TL;DR: Two commercial sealing alloys (Kovar® and Ceramvar®) were tested in high pressure hydrogen, or after exposure to hydrogen gas for up to 17,500 h as discussed by the authors.
Abstract: Two commercial sealing alloys (Kovar® and Ceramvar® were tested in high pressure hydrogen, or after exposure to hydrogen gas for up to 17,500 h. All hydrogen pressures were 69 MPa. In no case was any ductility loss observed. It was therefore concluded that these alloys are probably safe for use in gas handling systems which contain hydrogen.
6 citations
TL;DR: In this paper, the effects of C3A content, fineness, gypsum content, C3S:C2S ratio, and alkali content of the cement on the correlation between 1-day accelerated and 28-day normal strength of concrete were investigated.
Abstract: The effects of C3A content, fineness, gypsum content, C3S:C2S ratio, and alkali content of the cement on the correlation between 1-day accelerated and 28-day normal strength of concrete were investigated. The accelerated testing method used was that developed by the Institution of Civil Engineers (ICE) Accelerated Testing Committee [1]. Both C3A and alkali content did not affect the correlation between accelerated and 28-day strength. Increased fineness caused the predicted 28-day strength to be less than actual. Increased gypsum content could cause an increase in accelerated strength and at the same time a decrease in 28-day strength. The ICE correlation was not applicable when cements of low C3S:C2S ratio were used.
5 citations
TL;DR: In this paper, the authors measured the contact angle of molten zinc drops on fifteen ceramic materials and four metals in high-purity helium and carbon monoxide atmospheres, and found that zinc of 99.9999 percent purity did not wet the oxide materials, glass-type coatings, or graphite.
Abstract: Measurements were made of the contact angle of molten zinc drops on fifteen ceramic materials and four metals in high-purity helium and carbon monoxide atmospheres. Zinc of 99.9999-percent purity did not wet the oxide materials, glass-type coatings, or graphite; all contact angles were greater than 90 deg at 500 to 700°C in helium and 500 to 800°C in carbon monoxide. Materials tested that were most resistant to wetting by zinc were ZnO sinter, glazed fireclay, graphite, and mullite.
TL;DR: In this paper, the standard temperatures of test are being changed from the traditional 100 and 210°F to 40 and 100°C. Graphs and tables are given which allow for easy, accurate calculation of kinematic viscosity at the new test temperatures from data at the former test temperatures.
Abstract: In the petroleum industry the standard temperatures of test are being changed from the traditional 100 and 210°F to 40 and 100°C. Graphs and tables are given which allow for easy, accurate calculation of kinematic viscosity at the new test temperatures from data at the former test temperatures.
TL;DR: In this paper, a controlled laboratory experiment using a 50,000-Ci gamma irradiator is used as an example to exemplify the use of Statistical Design of Corrosion Experiments.
Abstract: The scope of metallurgical engineering applied research and development of cladding and encapsulation materials has been extended during recent years beyond those materials used in core and cladding and in non-core structural nuclear applications in research and power reactors. Materials for the encapsulation of radioisotopes for medical and commercial uses must also be carefully selected for their suitability for exposure initially up to two years in the reactor followed by four or five years in service. The susceptibility to corrosion of all of these materials is a most important consideration. Conventional weight loss and potentiostatic experiments require careful design of both the physical corrosion assembly and experimental method. In this paper a controlled laboratory experiment using a 50,000-Ci gamma irradiator is used as an example to exemplify the use of Statistical Design of Corrosion Experiments.
TL;DR: In this paper, the effect of single and periodic intermediate surface layer removal on the fatigue behavior of oxygen-free, highconductivity copper was studied in the life range of 105 to 2 × 106 cycles.
Abstract: The effect of single and periodic intermediate surface layer removal on the fatigue behavior of oxygen-free, high-conductivity copper was studied in the life range of 105 to 2 × 106 cycles. The fatigue tests were conducted at room temperature, in tension-compression, under load control, and without mean load. The surface layer removal was accomplished by electropolishing. The variables of the test conditions were the engineering stress range, the average grain size, and the atmosphere (air and argon gas). A single treatment of removing all the surface markings (caused by fatigue) during the life increased the subsequent fatigue life significantly. The largest increase in life was obtained after the largest period of precycling, which was about 80 percent of the standard life. The average plastic strain ranges after the polishing treatments were measured. The fatigue lives after polishing were strongly dependent upon the depth of the removed surface layer. Periodic treatments to remove all the surface markings during the life also increased the fatigue life. Removal of all the surface markings after every 80 percent of the standard life increased the life by a factor of ten.
TL;DR: In this paper, a new approach to decreasing the fatigue strength reduction factor of holes in ductile sheet metallic material is presented, where the material is first stretched by dimpling centering about the region where the hole is to be made.
Abstract: A new approach to decreasing the fatigue strength reduction factor of holes in ductile sheet metallic material is presented. The material is first stretched by dimpling centering about the region where the hole is to be made. Subsequent flattening of the material creates residual compressive stresses in the dimple region. The hole is then drilled leaving the peripheral material in a state of compressive stress. Zero-to-tension fatigue tests on nominally 0.050-in. (1.27-mm) thick 2024-T3 alclad aluminum alloy specimens show a 36 percent decrease in the fatigue strength reduction factor by dimpling for 106 cycles to failure.
TL;DR: The fatigue life of nickel-plated copper depends upon the thickness of the nickel coating as discussed by the authors, and increases in life from 150 to 450 percent were obtained by increasing the thickness from 0.0001 to 0.005 in.
Abstract: The fatigue life of nickel-plated copper depends upon the thickness of the nickel coating. Increases in life from 150 to 450 percent were obtained by increasing the thickness of the nickel from 0.0001 to 0.00025 in. (0.00254 to 0.00635 mm). A further increase in thickness to 0.005 in. (0.0127 mm) resulted in an increase in life of 200 percent. Interrupting the current during electroplating produces interfaces within the coating and increases the fatigue life for a given thickness. Increases in life of 110 percent were obtained by applying a 0.0005-in. thick coating in five layers, rather than in a single layer.
TL;DR: In this paper, the crack propagation rate was studied on axially loaded specimens of oxygen-free, high conductivity copper tested in the high cycle life region, where the variables of the test conditions were the engineering stress range, the average grain size, and the atmosphere (air and argon gas).
Abstract: The crack propagation rate was studied on axially loaded specimens of oxygen-free, high conductivity copper tested in the high cycle life region. Fatigue tests were conducted under load control without a mean load. The variables of the test conditions were the engineering stress range, the average grain size, and the atmosphere (air and argon gas). The crack propagation rate during the first 80 percent of the life was determined by using an electropolishing technique. The rate was also measured after final failure of each specimen from the distances of the striations on the fracture surface observed through a scanning electron microscope. The crack propagation rate depended upon the test conditions as well as on the prior stress cycling. The crack propagation was divided into two main stages: the crack nucleation and microcrack development stage, and the crack propagation or macrocrack development stage. Argon gas atmosphere reduced the macrocrack propagation rate, but did not affect the crack nucleation and microcrack development significantly. Increasing the grain size shortened the crack nucleation stage markedly.
TL;DR: In this article, the critical values of Young's nonparametric D statistic are presented for early termination of statistical precedence tests in accelerated life test comparisons, and use of the tables is explained for acclerated comparisons of the proposed and present designs.
Abstract: Tables are presented for critical values of Young's nonparametric D statistic, which may permit early termination of statistical precedence tests in accelerated life test comparisons. Use of the tables is explained for acclerated comparisons of the proposed and present designs.
TL;DR: In this article, an evaluation of the life test for 80Ni-20Cr alloys specified in ASTM B 76 has been made and it is shown that the emissivity of the wire is not constant after the pretreatment but requires about an additional four hours at the test temperature.
Abstract: An evaluation of the life test for 80Ni-20Cr alloys specified in ASTM B 76 has been made. It is shown that the emissivity of the wire is not constant after the pretreatment but requires about an additional four hours at the test temperature. The convection coefficient increases continuously during the life test causing more power to be dissipated by convection as the test progresses. The small resistance change during the test is a balance between relatively large changes in both the resistivity and the dimension of the sample. A unique expression is developed that enables the change in resistivity to be determined from electrical data. Calculated decreases in chromium and in the diameter of the wire are compared to experimental values. Failure occurs after the alloy has lost about 6 percent chromium and about 10 percent of its cross-sectional area.
TL;DR: A computer program has been developed to optimize hydraulic pressure system selection for use in the structural testing of aeronautical vehicles, to select the minimal number of pressure systems to match all the simulated flight loads which are applied during a test.
Abstract: A computer program has been developed to optimize hydraulic pressure system selection for use in the structural testing of aeronautical vehicles. This program will select the minimal number of pressure systems, using available hydraulic cylinders, to match all the simulated flight loads which are applied during a test. Programs were written for Fortran and Advanced Basic language users of the IBM 360/67 time-sharing system or the Varian 620/i stand-alone system. Various options are present in the programs to adjust for unique testing conditions. Since the number of pressure system combinations for large-scale testing can be astronomical, this program has eliminated what was formerly a frustrating, time-consuming, and highly subjective task.
TL;DR: In this article, the creep behavior of coated Ta-10W and Ta-17W alloys was evaluated at 2600 to 3200°F and the results have been used to derive empirical equations that predict short-time creep life in this temperature range.
Abstract: Uncoated Ta-17W and C129Y alloys and coated Ta-10W, C103, and C129Y alloys have been evaluated for short-time creep behavior at 2600 to 3200°F. The time for creep strains of up to 2 percent has been measured and the results have been used to derive empirical equations that predict short-time creep life in this temperature range. The equations give estimates of the time-to-creep strains of up to 2 percent at stress levels that will produce the maximum strain in 60 min or less. Silicide-base coatings appear to add to the creep strength of coated Ta-10W but have little added effect on the strength of the columbium-base alloys. The creep behavior of coated metals can be analyzed by the same empirical methods as those used for uncoated substrates. The results show that commercially available silicide coatings protect the substrate from oxidation with creep strains of up to 2 percent on exposures of 1 to 1½ h in this temperature range.
TL;DR: The resistance of Alloy XM-27 to a variety of high-temperature environments was investigated in this article, where the alloy was tested in cyclic and semicontinuous oxidation and sulfidizing environments and the results were compared to conventional, heat resistant alloys.
Abstract: The resistance of Alloy XM-27 to a variety of high-temperature environments was investigated. The alloy was tested in cyclic and semicontinuous oxidation and sulfidizing environments, and the results were compared to conventional, heat resistant alloys. Elevated tensile and stress rupture properties and resistance to embrittlement at 482, 704, and 982°C (900, 1300, and 1800°F) were evaluated.
TL;DR: A coaxial-cylinder apparatus has been designed for steady-state and non-steady-state measurements as mentioned in this paper, and the cell was calibrated by using several gases of known thermal conductivity (air, helium).
Abstract: A coaxial-cylinder apparatus has been designed for steady-state and for non-steady-state measurements The cell was calibrated by using several gases of known thermal conductivity (air, helium) The thermal conductivity of Refrigerant 12 (R 12) in the liquid and gaseous states at temperatures up to 095 Tcr and at pressures to 16 MPa has been determined Erratum to this paper appears in 3(1)
TL;DR: In this paper, the distinction between coaxial and noncoaxial strains is explained and a test for coaxiality based on the use of squares and parallelograms for the strain measurements is presented.
Abstract: The distinction between coaxial and noncoaxial strains is explained. It is shown that with noncoaxial strains deformation does not necessarily produce a change of shape, if circles and ellipses are used for strain measurements. If materials are tested in exisymmetrical processes, in which the strains are coaxial, and used in unsymmetrical ones, in which the strains are noncoaxial, then the formability will appear to be overestimated. A test for coaxiality, based on the use of squares and parallelograms for the strain measurements, is presented in the text and the formula used is derived in the Appendix.
TL;DR: In this article, an analysis was made of three factors (fringe width, phase change, and surface roughness) which contribute to errors in measurement of coating thickness with a double-beam interference microscope.
Abstract: An analysis was made of three factors (fringe width, phase change, and surface roughness) which contribute to errors in measurement of coating thickness with a double-beam interference microscope Excluding any unpredictable contributions made by surface roughness, a theoretical analysis based on a literature search revealed that the total of the two remaining errors will not exceed ±019 μm (±00076 mil) if either the coating or its substrate is a metal If both are metals, the error will not exceed ±012 μm (±00048 mil) Measurements were made on a few samples of common coating systems The errors experienced were much less than the above theoretical values, and would not normally contribute significantly to measurements with the double-beam interference microscope
TL;DR: In this article, an experimental investigation of stress corrosion cracking in metals is reproted for several alloy-corrodent systems and it is shown that susceptibility to stress corrosion is associated with decreases in the peak amplitudes of the internal damping curves.
Abstract: An experimental investigation of stress corrosion cracking in metals is reproted for several alloy-corrodent systems. Internal damping measurements are made on the metals in the as-received condition and after they have been exposed to a corrosive environment. Data curves are reported for different grain sizes of 2024-T4 aluminum in a mercury-corrodent environment and for 304 stainless steel in boiling MgCl2. Considerable changes in the diffusion peaks of these alloys are observed following their exposure in a stressed state to the environment in which they are known to be susceptible to stress corrosion cracking. Corroborative tests on electrolytic copper stressed in a corroding environment of air-saturated synthetic seawater indicate no changes in its internal damping characteristics. This material is immune to stress corrosion cracking in the seawater environment. This study is developed from the idea that metals which are susceptible to stress corrosion cracking exhibit changes in their damping properties after environmental exposure. From the experimental evidence obtained, susceptibility to stress corrosion cracking is associated with decreases in the peak amplitudes of the internal damping curves. The decrease occurs across either the thermal diffusion peak associated with the specimen thickness or with the grain size of the metal. Moreover, for alloys immune to stress corrosion cracking, it is shown that the peak amplitudes remain unchanged after environmental exposure and when compared to the same data curve for the as-received material. From these studies it is concluded that the decreased amplitudes of the internal friction peaks indicate the susceptibility to stress corrosion cracking. This decrease results from the thermal diffusion effects associated either with the specimen thickness or with the grain size. For nonsusceptible systems, the peak amplitudes remain unchanged after environmental exposure. The specific aluminum alloy and stainless steel are used in order to demonstrate a basic phenomenon. It should not be construed that neither aluminum alloys nor stainless steels are useful marine alloys.
TL;DR: In this article, it was shown that an error in the calculated gas transmission rate of greater than 20 percent can result when using the standard equation presented in Method M of the American Society for Testing and Materials Test for Gas Transmission Rate of Plastic Film and Sheeting [D 1434-66 (1972)].
Abstract: It is shown that an error in the calculated gas transmission rate of greater than 20 percent can result when using the standard equation presented in Method M of the American Society for Testing and Materials Test for Gas Transmission Rate of Plastic Film and Sheeting [D 1434–66 (1972)]. The magnitude of this error is shown to be a function of both cell void volume and pressure. Therefore, disagreements in results calculated using different cells and operating conditions can be explained. The exact solution of the equation is presented together with an approximation; the latter facilitates calculations and results in an error of less than one percent.
TL;DR: In this paper, contamination problems inherent in the preparation of high-purity chemicals must be recognized and controlled, such as airborne contamination, leaching from containers, and reagents for ultratrace elemental analysis are reviewed.
Abstract: Contamination problems inherent in the preparation of high-purity chemicals must be recognized and controlled. Major problems such as airborne contamination, leaching from containers, and reagents for ultratrace elemental analysis are reviewed. Trace impurities contributed by electrostatic charges, filtration media, and water are discussed.
TL;DR: In this article, the acoustic emissions emitted from a 17-4 PH stainless steel were monitored while the specimen was undergoing fatigue testing in the torsional mode, and at and above cyclical stress sensitivity limit (CSSL) emissions were detected which could be attributed to fatigue damage which resulted in failure of the specimen.
Abstract: The acoustic emissions emitted from a 17-4 PH stainless steel were monitored while the specimen was undergoing fatigue testing in the torsional mode. Below the cyclical stress sensitivity limit (CSSL) of the material no abnormal emissions were detected, while at and above CSSL emissions were detected which could be attributed to fatigue damage which resulted in failure of the specimen. This test was the first in a series which will enable us to learn more about fatigue damage in various materials.