Search results

René 142 is a high strength, nickel-base directionally solidified (DS) alloy that has high rupture strength, excellent resistance to grain boundary cracking, and superior high-velocity oxidation resistance.
The cost of a typical turbine blade ranges from USD 500 to 10000, and if the total number of blades in a gas turbine engine is considered, the estimated replacement cost is in the ranges of hundreds of thousands to millions of dollars for each gas turbine engine.
Turbine components cast with EQ morphologies are vulnerable to failure as they contain randomly oriented grain boundaries which can be perpendicular to the loading directions.
In DS morphologies, the grain structure is parallel to the major axis of the blade and contains limited number of transverse grain boundaries that are perpendicular to the loading directions.
The turbine components can also be cast with single-crystal (SX) morphology that contains no grain boundaries at all.

And the original austenite grain (PAG) size is smaller due to higher steel grade.
And it contains dense acicular ferrite and a large number of cementite precipitates.
The boundary of acicular ferrite with different orientations is the prior austenite grain boundaries (PAGB), and the PAG size is between 10 μm and 20 μm.
And the shear radiation area showed fibrous, large-size shear ridges and a large number of shear ridges with small size.
In addition, there are a large number of small shear ridges in the fiber source area, with the length of 15-40 μm.

The closer the orientation was to the normal of the substrate, the faster was the grain height growth, forming a narrow and high “wall” that limited other oriented grains to “inside the wall”, thereby eliminating the non-perpendicular grains [26].
However, Figs. 5(c) and (d) show the stage (3) unstable growth with pores in the grain boundaries.
Holes were found locally, along with the incompletely fused gaps between the grains shown in Figs. 6(c) and (d).
This was attributed to the fact that the increase in the supersaturation improved the degree of fusion between the grains and the grains were relatively dense.
Acknowledgments This work is supported by the National Natural Science Foundation of China [grant number 11827802].

In first phase, all the grains reach the equilibrium state with gravity, and the rigid wheel does not contact with the simulant lunar soil in this phase.
It is very difficult to know the behavior of grains under the wheel by measuring in experiment, but we can observe this change visualized through the DEM simulation, which is shown in figure 6.
The interaction of rug and the grains of all times is obtained, which includes the force, velocity, displacement etc.
Time of rug-wheel and non-rug-rug at 400 N wheel load and 40 mm/s translational velocity, and traction load on wheel is zero, where wheel diameter is 250 mm, the rug width is 5 mm, height is 10 mm, and the rug number is 18.
Fig.12 shows the sinkage z of rug-wheel and non-rug-rug at 400 N wheel load,40 mm/s translational velocity, and the slip radio is 0-80%, where the wheel diameter is 250 mm, the rug width is 10 mm, height is 5 mm, and the rug number is 18.

For bulk materials, texture is known to be influenced by cold work, recrystallization and grain growth.
Retained not fully- recrystallized elongated grains provide evidence that heat loss of the hot-rolling process is too fast to fully recrystallize the deformed/elongated grains in the very thin sheet situation.
The results were reproducible with both chambers and the main advantage of the new chamber comes from the enlarged windows allowing the study of a higher number of Bragg peaks of the phases present in the sample.
In this case <110> oriented grains of the Ni-Ti B2 phase dominate at small thicknesses while <211> oriented grains take over at larger thicknesses.
Grains oriented with their faster growing directions perpendicular to the surface are preserved while slower growing grains are terminated as they intersect the column walls of taller grains.

Ball clay (Seto, Japan) as the binder was added with 0.5 mass% to enhance the green strength during handling. 0.25mass% of MgO was added as the sintering aid and grain growth inhibitor.
No grain growth of alumina particles was observed.
It was observed that the porosity of specimen with the same PMMA additions varied with the laminate number.
With decrease in the number of laminate layers, the porosity was gradually increased for great benefit to the air permeability.
Two types of fracture behavior in laminated tubes varied with the PMMA addition, independent of the laminate number.

Introduction Since its inception, Midhani has been actively involved in development and supply of a number of special stainless steel for strategic applications.
Inadequate hot working can result in coarse-grained structure with carbide precipitation at grain boundaries which gives rise to low aged ductility and toughness in the products.
The microstructure showed continuous network around the grains.
The grain size was measured to be between ASTM No 5-6.
Conclusion Industry faces a number of challenges during the production phase of new alloys or to meet the stringent requirement of specification.

The error accumulates with the increase of the number of layers, eventually leading to the gap between the overall height and the height of theory.
So the crystals are columnar dendrites and the sizes of crystal grains are uniform along the direction of growth as shown in Fig.6.
If the power is still the same, the crystal grains are coarser than that of the bottom.
The temperature of the bath is passed into the atmosphere in the form of radiation partly with rapid cooling rate and small crystal grains (Fig.5c).
Seen from the microstructure distributions of the multilayer cladding, the peak value of hardness happens in the near-surface layers of fine-grained area, while the minimum hardness is in the coarse grain zone of the remelting zone between the two layers.

The average diameter of the a phase grains is about 11.0 mm.
With increasing quenching from temperature the grain size of b phase increase sharply.
The diameter of the b phase grains is above 400 mm.
More the number of fine needle-like traces of martensites were observed around the primary a phase.
(a) (b) (c) (d) ap Transformed b Zig-Zag grain boundary a' martensite equiaxed ap a' martensite Retained ap a' martensite b grain boundary ap Fig. 1.

EBSD-based images are distinctive by comparison with ordinary metallographic ones by recovering all 3 degrees of freedom associated with the local lattice orientation in crystalline grains.
A section of large-grain Mg-Ce material was carefully prepared by mechanical polishing.
The dendritic nature of the central grain in the Mg-Ce sample is evident in Figure 1.
These linear features clearly lie on several distinctive planes, reflecting the varied lattice orientation of the constituent grains.
Some heterogeneity of the average dislocation density between individual grains of the sample is evident at 3.6% strain, whereas no such differentiation is observed at 0.6% strain.