Single-crystal microtubes of a novel apatite-type compound, (Na2.5Bi2.5)(PO4)3(F,OH), with well-faceted hexagonal cross sections

Abstract The microstructure of as-cast cored turbine blades roots, made of the single-crystal CMSX-4 nickel-based superalloy was investigated. Analysed blades were obtained by directional solidification technique in the industrial ALD Bridgman induction furnace. The investigations of the microstructure of blades roots were performed using SEM and X-ray techniques including diffraction topography with the use of Auleytner method. Characteristic shapes of dendrites with various arrangement were observed on the SEM images taken from the cross-sections, made transversely to the main blades axis. The differences in quality of the structure in particular areas of blades roots were revealed. Based on the results, the influence of cooling bores on blades root structure was analysed and the changes in the distribution and geometry of cooling bores were proposed.

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The location of p-dichlorobenzene in a single crystal of zeolite H-ZSM-5 at high sorbate loading

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768195008524 ◽

1996 ◽

Vol 52 (1) ◽

pp. 140-144 ◽

Cited By ~ 37

Author(s):

H. van Koningsveld ◽

J. C. Jansen ◽

H. van Bekkum

Keyword(s):

Single Crystal ◽

Cross Sections ◽

Unit Cell ◽

Molecular Axis ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

Acta Cryst ◽

Elliptical Cross ◽

X Ray ◽

Structural Aspects

The crystal structure of a high-loaded complex of H-ZSM-5 with eight molecules of p-dichlorobenzene per unit cell has been solved by single-crystal X-ray diffraction. The orthorhombic space group P212121 with a = 20.102 (6), b = 19.797 (9), c = 13.436 (3) Å and V = 5347 (3) Å3 has four Si23.92Al0.08O48.2C6H4Cl2 units per unit cell. Dx = 2.164 Mg m−3, λ(MoKα) = 0.71073 Å and μ(Mo Kα) = 0.876 mm−1. The final R(wR) = 0.046 (0.039), w = 1/σ 2(F), for 6090 observed reflections with I > 1.0σ(I) measured at 293 K. The straight channel parallel to [010] is slightly corrugated. The elliptical cross sections have limiting apertures of 6.0 × 4.9 Å (r oxygen = 1.35 Å). The sinusoidal channel parallel to [100] is elliptical with major and minor axes of 6.1 × 4.8 Å, respectively. One of the two independent p-dichlorobenzene molecule lies at the intersection of the straight and sinusoidal channels with its long molecular axis almost parallel to (100) and deviating ~8° from [010]. The second p-dichlorobenzene molecule is in the sinusoidal channel. Its long molecular axis deviates almost 7° from [100] and is practically parallel to (010). The structural aspects are in all details comparable to those in the high-loaded H-ZSM-5/p-xylene complex [van Koningsveld, Tuinstra, van Bekkum & Jansen (1989). Acta Cryst. B45, 423–431] , except for the main interaction forces between the p-dichlorobenzene molecules at the channel intersection.

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Characterization of the mechanical behavior of wear surfaces on single crystal nickel by nanomechanical techniques

Journal of Materials Research ◽

10.1557/jmr.2009.0075 ◽

2009 ◽

Vol 24 (3) ◽

pp. 844-852 ◽

Cited By ~ 4

Author(s):

M.J. Cordill ◽

N.R. Moody ◽

S.V. Prasad ◽

J.R. Michael ◽

W.W. Gerberich

Keyword(s):

Mechanical Properties ◽

Single Crystal ◽

Mechanical Behavior ◽

Cross Sections ◽

Focused Ion Beam ◽

Surface Deformation ◽

Ion Beam ◽

Test Methods ◽

Strong Increase ◽

Number Of Cycles

In ductile metals, sliding contact induces plastic deformation resulting in subsurfaces, the mechanical properties of which are different from those of the bulk. This article describes a novel combination of nanomechanical test methods and analysis techniques to evaluate the mechanical behavior of the subsurfaces generated underneath a wear surface. In this methodology, nanoscratch techniques were first used to generate wear patterns as a function of load and number of cycles using a Hysitron TriboIndenter. Measurements were made on a (001) single crystal plane along two crystallographic directions, <001> and <011>. Nanoindentation was then used to measure mechanical properties in each wear pattern. The results on the (001) single crystal nickel plane showed that there was a strong increase in hardness with increasing applied load that was accompanied by a change in surface deformation. The amount of deformation underneath the wear patterns was examined from focused ion beam cross-sections of the wear patterns.

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