Requirements on Tools and Machines When Machining Hard Materials

1986 ◽  
pp. 349-357 ◽  
Author(s):  
H. K. TÖnshoff ◽  
W. Bussmann ◽  
C. Stanske
Keyword(s):  
Hard Materials

Measurements in 3D images

1991 ◽  
Vol 49 ◽  
pp. 408-409
Author(s):  
John C. Russ
Keyword(s):  
Three Dimensional ◽  
Image Plane ◽  
X Rays ◽  
Traditional Use ◽  
3D Images ◽  
Confocal Scanning Laser Microscope ◽  
Hard Materials ◽  
Depth Direction ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

Three-dimensional (3D) images consisting of arrays of voxels can now be routinely obtained from several different types of microscopes. These include both the transmission and emission modes of the confocal scanning laser microscope (but not its most common reflection mode), the secondary ion mass spectrometer, and computed tomography using electrons, X-rays or other signals. Compared to the traditional use of serial sectioning (which includes sequential polishing of hard materials), these newer techniques eliminate difficulties of alignment of slices, and maintain uniform resolution in the depth direction. However, the resolution in the z-direction may be different from that within each image plane, which makes the voxels non-cubic and creates some difficulties for subsequent analysis.

scholarly journals A New Method to Calculate Water Film Stiffness and Damping for Water Lubricated Bearing with Multiple Axial Grooves

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Guojun Ren
Keyword(s):  
Analytical Procedure ◽  
Load Capacity ◽  
Water Film ◽  
New Method ◽  
Hard Materials ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
Hydro Turbines

Abstract Water lubricated guide bearings for hydro turbines and pumps are conventionally designed with multiple axial grooves to provide effectively cooling and flushing away abrasives. Due to the variety of groove configuration in terms of number and size, a predication of their performance is difficult. This paper deals with an analytical procedure to investigate groove effect on load capacity, stiffness and damping for this type of bearing where it is considered as an assembly of many inclined slide bearings. The result can be applied to bearings made of hard materials combined with low bearing pressure.

ChemInform Abstract: Hard Materials Based on Cemented TiB2-WC-Co Alloys.

ChemInform ◽  
2010 ◽  
Vol 26 (9) ◽  
pp. no-no
Author(s):  
Z. T. ZAKHARIEV ◽  
M. S. IVANOVA ◽  
T. I. SEREBRIAKOVA
Keyword(s):  
Hard Materials ◽  
Co Alloys

A Combination Method of Charge Density Measurement in Hard Materials Using Accurate, Quantitative Electron and X-ray Diffraction: The α-Al2O3 Case

2003 ◽  
Vol 9 (5) ◽  
pp. 419-427 ◽  
Author(s):  
Victor A. Streltsov ◽  
Philip N.H. Nakashima ◽  
Andrew W.S. Johnson
Keyword(s):  
Charge Density ◽  
Multiple Scattering ◽  
Density Measurement ◽  
Bloch Wave ◽  
Combination Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hard Materials ◽  
Structure Factors ◽  
Free Data

Current X-ray diffraction techniques intended for “ideally imperfect” specimens provide structure factors only on a relative scale and ever-present multiple scattering in strong low-angle Bragg reflections is difficult to correct. Multiple scattering is implicit in the quantitative convergent beam electron diffraction (QCBED) method, which provides absolutely scaled structure factors. Conventional single crystal X-ray diffraction has proved adequate in softer materials where crystal perfection is limited. In hard materials, the highly perfect nature of the crystals is often a difficulty, due to the inadequacy of the conventional corrections for multiple scattering (extinction corrections). The present study on α-Al2O3 exploits the complementarity of synchrotron X-ray measurements for weak and medium intensities and QCBED measurement of the strong low-angle reflections. Two-dimensional near zone axis QCBED data from different crystals at various accelerating voltages, thicknesses, and orientations have been matched using Bloch-wave and multislice methods. The reproducibility of QCBED data is better than 0.5%. The low-angle strong QCBED structure factors were combined with middle and high-angle extinction-free data from synchrotron X-ray diffraction measurements. Static deformation charge density maps for α-Al2O3 have been calculated from a multipole expansion model refined using the combined QCBED and X-ray data.

Sign in / Sign up

Export Citation Format

Share Document