The role of intakes in deformation twiming of Iamellar TiAl (ywl~l (a*) crystals creep deformed at an ekvated temperature have been investigated. Since the multiplication of lattice dislocations within both y and etzlamellae is very limited as a result of a refined lamekr microstmture, the gliding of interfheii dislocations on both y/a2 and y/y interfaces (i.e. interface sliding) becomes an imp...

The future nanotechnology requires materials which are dimensionally and elastically stable within the nm-domain. Because of their elastic stability, Cu-Be alloys are often used for the fabrication of elastic force sensors (spring elements). Anelastic and viscous creep limit the precision of such sensors. Therefore we have studied the anelastic and viscoelastic relaxations of Cu-Be using laser ...

Solder joints are the main weak points of power modules used in harsh environments. For the power module of electric vehicles, the maximum operating temperature of a chip can reach 175 ◦C under driving conditions. Therefore, it is necessary to study the high-temperature reliability of solder joints. This study investigated the creep properties of Sn-3.0Ag-0.5Cu (SAC305) and Sn-8.0Sb-3.0Ag (SSA8...

Abstract Stress reduction creep tests conducted on a Cu-Cr-Nb alloy (GRCop-84) at 923 K have confirmed local dislocation climb to be the rate-controlling deformation mechanism. The activation energy of was measured consistent with that self-diffusion in Cu matrix. An internal back stress approximately -9 MPa identified act dislocations, which is believed sum for dislocation-particle interaction...

As the primary choice for aero-engine turbine blades, creep resistance is an important mechanical property developing third-generation single crystal Ni-based superalloys. The behavior of superalloy in [001] orientation was studied at 980 °C under a series stress levels, accompanied with scanning electron microscope (SEM) and transmission (TEM) observation to investigate microstructure deformat...

Cast and aged Al-Sc microalloys are creep-resistant to 300‰, due to the blocking of dislocations by nanosize, coherent Al3Sc (L12) precipitates. Rare-earth elements substitute for Sc in these precipitates, leading to a higher number density of smaller precipitates, which have a greater lattice-parameter mismatch with Al than in the Al-Sc binary microalloy. This leads to an improvement in both a...

A study was conducted to characterize the microstructure of electron beam welds in high purity niobium and its effect on creep behaviour at room temperature. The parent material was 2mm sheet with a 50 μm grain size. The weld fusion zone had ~ 1mm grains, implying that these grains all intersected the free surface. The parent material showed no room temperature creep deformation below the yield...

Creep deformation in < 001 > oriented single crystals of CMSX-3 has been studied at temperatures around 850°C at a stress level of 552 MPa. Detailed observations of the evolution of the dislocation structure during creep have been made. TEM stereo pairs show creep deformation in the matrix phase, leaving the 7’ precipitates undeformed. In previously undeformed crystals there is a brief incubati...

Several hypotheses have been proposed to explain trench-parallel shear wave splitting in the mantle wedge of subduction zones. These include 3-D flow effects, parallel melt filled cracks, and B-type olivine fabric. We predict the distribution of Btype and other fabrics with high-resolution thermal and stress models of subduction zones. A composite viscous rheology is used that incorporates wet ...