SCHMELZMETALL HOVADUR CCB

Schmelzmetall Hovadur CCB is a heat-treatable, copper-cobalt-beryllium alloy. In the solution heat treated and artificially aged condition, this alloy combines good mechanical strength and excellent ductility as well as high softening temperature with good thermal and electrical conductivity. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-920. Producer or source: Schmelzmetall AG.

ZAPP TiAl6V4

Zapp TiAl6V4 is an alpha-beta titanium alloy that is used in the annealed or solution heat treated and aged condition for applications requiring high strength, relatively low weight, and excellent corrosion resistance. It is typically used in the low to moderate temperature range (up to about 400 °C, or 750 °F). Ti-6Al-4V is the most widely used titanium alloy, accounting for more than 50% of the total titanium used. The aerospace industry accounts for more than 80% of this usage. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-173. Producer or source: Zapp AG.

Excellent age hardenability with the controllable microstructure of AXW100 magnesium sheet alloy

Age-hardenability and corresponding improvement of the mechanical properties of Mg–1Al–0.7Ca and Mg–1Al–0.7Ca–0.7Y alloy sheets are addressed with respect to the microstructure and texture evolution during thermomechanical treatments. A fine grain structure and weak texture with the basal pole split into the sheet transverse direction are retained in the Mg–1Al–0.7Ca–0.7Y sheet even after the homogenization at 500 °C, due to the grain boundary pinning by Y-containing precipitates possessing a high thermal stability. Contrarily, the Mg–1Al–0.7Ca sheet shows a coarse microstructure and basal-type texture after the homogenization. The peak-aged condition is attained after the aging at 250 °C for 1800 s of both homogenized sheets, while the Y-containing sheet shows a higher hardness than the Mg–1Al–0.7Ca sheet. TEM analysis and thermodynamic calculation show the formation of metastable precipitates composed of Al, Ca, Y and Mg in the Mg–1Al–0.7Ca–0.7Y sheet at the homogenized and peak-aged conditions. A significant increase in the yield strength is obtained in the peak-aged condition from 162 MPa after the homogenization to 244 MPa, which arises from the increased size and number density of the precipitates. The high age-hardenability of the Mg–1Al–0.7Ca–0.7Y sheet attributes to the superior mechanical properties with an improved ductility promoted by the weak texture.

ATI 6-4

ATI 6-4 is an alpha-beta, Ti-6Al-4V alloy that is used in the annealed condition, or in the solution heat treated and aged condition. This high-strength alloy can be used at cryogenic temperatures up to about 425 °C (800 °F). Ti-6Al-4V is the most widely used titanium alloy. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-171. Producer or source: ATI.

SCHMELZMETALL HOVADUR CCZ

Schmelzmetall Hovadur CCZ is a heat-treatable, copper-chromium-zirconium alloy. In the solution heat-treated and artificially aged condition, this alloy exhibits high thermal and electrical conductivity along with high strength and a high softening temperature. Hovadur CCZ evolved from CuCr1 (CW105C), a precipitation-hardenable alloy first made in the 1930s for spot welding electrodes, for which strength and hardness at temperatures up to 500 °C (930 °F), as well as good electrical and thermal conductivity, are essential. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: Cu-912. Producer or source: Schmelzmetall AG.

Effect of Aging Heat Treatment Conditions on the Mechanical Properties and Microstructure of Base and Weld Metal of Alloy 282 Superalloy

The effect of aging heat treatment conditions on the mechanical properties and microstructure of the base and weld metal of Alloy 282 superalloy was investigated. The aging heat treatment conditions employed in this study were as follows: two-steps (1010 °C for 2 hours plus 788 °C for 8 hours) and one-step at 788 °C, 738 °C, and 688 °C for 4 hours. The base metal with the one-step aged condition exhibited lower hardness but longer creep life than that treated with the two-step aged condition. The base metal subjected to the two-step aging exhibited the highest hardness and the shortest creep life, mainly due to the precipitation of Mo-rich M6C-type carbides and coarse <i>γ</i>' (Ni3(Al,Ti)) phase. For the weld metal, regardless of aging heat treatment conditions, creep elongation and life decreased significantly compared to the base metal, due to the coarse effective grain size and inhomogeneous distribution of <i>γ</i>' precipitates.

Failures of Flexible Diaphragm Couplings of Power Take Off (PTO) Shafts of an Aircraft by Surface Discontinuity, Controlled by Stress Concentration or Stress Intensity Factor

Failures of two power take off (PTO) shafts of an aircraft have been analysed. Two shafts, one each developed by two different manufacturers failed separately during power run endurance test conducted at room temperature and ambient normal atmosphere. In both the cases, cracks were observed on the outer diaphragm disc. One shaft showed cracking in the engine side, while the other one exhibited cracks in the aircraft mounting accessory gearbox (AMAGB) side. Chemical analysis, microstructure and hardness evaluation indicate that the diaphragm material of the shafts is Ti-6Al-4V alloy used in solution treated and aged condition, as per the desired specification AMS 4928. Microstructural in-homogeneity, possibly a result of improper forging, was observed in diaphragm material of both the shafts. Additionally, surface discontinuities induced by forging and subsequent insufficient machining were noticed on the diaphragms. The diaphragms failed by fatigue with cracks possibly nucleating at surface discontinuities. Discontinuities with lower availability in one shaft led to somewhat increased life (466 million cycles) as compared to the life (104 million cycles) of the other shaft. Another possible factor contributing to lower life in the later shaft is the presence of higher quantity of nitrogen rich inclusions. Controlling factor triggering the failure of diaphragm of shaft with lower life seems to be the available high stress level along the rim periphery, while that for shaft with higher life is presence of few localized sharp surface discontinuities.

Analysis of Fatigue and Healing Properties of Conventional Bitumen and Bio-Binder for Road Pavements

The analysis of fatigue behavior of bituminous binders is a complex issue due to several time-temperature dependent phenomena which interact simultaneously, such as damage accumulation, viscoelasticity, thixotropy, and healing. The present research involves rheological measurements aimed at evaluating the fatigue behavior and compares the self-healing capability of two plain bitumen and a bio-binder obtained by partially replacing one of the plain bitumen with a renewable bio-oil. Healing potential was assessed by means of an experimental approach previously implemented for modified bitumen and bituminous mastic and based on the use of a dynamic shear rheometer (DSR). The effects of some variables such as bitumen type, bio-oil addition, and aging on the healing potential of binders were taken into account. Results showed that the above-mentioned method for healing analysis is also suitable for conventional and bio-add binders. Outcomes of the experimental investigation highlight that fatigue and self-healing are mainly dependent on binder consistency and also affected by aging. Finally, the addition of bio-oil may induce even better performances in terms of healing potential compared to conventional bitumen, especially in aged condition.

Influence of Zn and Sn on the Precipitation Behavior of New Al–Mg–Si Alloys

In this study, we demonstrate how Zn and Sn influence hardening behavior and cluster formation during pre-aging and paint bake treatment in Al–Mg–Si alloys via hardness tests, tensile tests, and atom probe tomography. Compared to the standard alloy, the Sn-modified variant shows reduced cluster size and yield strength in the pre-aged condition. During the paint bake cycle, the clusters start to grow very fast and the alloy exhibits the highest strength increment. This behavior is attributed to the high vacancy binding energy of Sn. Adding Zn increases the formation kinetics and the size of Mg–Si co-clusters, generating higher yield strength values for both the pre-aged and paint baked conditions. Simultaneous addition of Zn and Sn creates a synergistic effect and produces an alloy that exhibits moderate strength (and good formability) in the pre-aged condition and accelerated hardening behavior during the paint bake cycle.