Characterization of the interfacial-microstructure evolution and void shrinkage of Ti-22Al-25Nb orthorhombic alloy with different surface roughness during diffusion bonding

The solid-state diffusion bonding experiments of high Nb containing TiAl alloy were successfully carried out at 950°C under a uniaxial pressure of 30MPa for 45min, and the influence of different initial microstructures, such as initial forged microstructure (named duplex microstructure) with different grain sizes, near lamellar microstructure and full lamellar microstructure, on the interface of the bonding joints were investigated. And the microstructure characterization of interfaces was taken by OM, SEM, EDS and micro-hardness tester. The results indicated that the grain size and strain energy are of great importance to improve the quality of interfacial bonding. Besides, the interfacial microstructure was found different from matrix and changed during the diffusion bonding process. Meanwhile, micro-hardness tests of the three kinds of joints showed that the micro-hardness in the interface was slightly higher than matrix in all the joints, resulted from the working hardening of the interface under the uniaxial pressure.

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Complex s-Plane Modeling and 2D Characterization of the Stochastic Scattering Loss in Symmetric Dielectric Slab Waveguides Exhibiting Ergodic Surface-Roughness with an Exponential Autocorrelation Function

IEEE Access ◽

10.1109/access.2021.3092635 ◽

2021 ◽

pp. 1-1

Author(s):

Ata Zadehgol

Keyword(s):

Surface Roughness ◽

Autocorrelation Function ◽

Dielectric Slab ◽

Scattering Loss ◽

Slab Waveguides

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Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽

10.3390/ma14061376 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1376

Author(s):

Alex Quok An Teo ◽

Lina Yan ◽

Akshay Chaudhari ◽

Gavin Kane O’Neill

Keyword(s):

Surface Roughness ◽

Stainless Steel ◽

Surface Characterization ◽

High Surface ◽

Surface Characteristics ◽

Post Processing ◽

Stainless Steel 316L ◽

Processing Methods ◽

Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

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Interfacial Microstructure Evolution of Copper/Aluminium Laminates with Different Annealing Processes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2976 ◽

2011 ◽

Vol 239-242 ◽

pp. 2976-2980 ◽

Cited By ~ 2

Author(s):

Ying Hui Zhang ◽

Jing Qin ◽

Hong Jin Zhao ◽

Gao Lei Xu

Keyword(s):

Intermetallic Compounds ◽

Incubation Period ◽

Microstructure Evolution ◽

Diffusion Zone ◽

Interfacial Microstructure ◽

Combination Process ◽

Local Areas

The interfacial microstructure evolution of copper/aluminium laminates with different annealing processes was studied. It was found that the formation and growth of intermetallic compounds in the interface during metallurgical combination process have four stages: the incubation period, the formation of island-like new phases in local areas, the transverse-lengthwise-transverse growth of diffusion zone, the formation of new intermetallic compounds and thickening of diffusion zone.

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Skewness and Kurtosis: Important Parameters in the Characterization of Dental Implant Surface Roughness—A Computer Simulation

ISRN Materials Science ◽

10.5402/2011/305312 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 22

Author(s):

Karl Niklas Hansson ◽

Stig Hansson

Keyword(s):

Surface Roughness ◽

Shear Strength ◽

Roughness Parameter ◽

Interface Shear Strength ◽

Interface Shear ◽

Implant Surface ◽

Bone Response ◽

Dental Implant Surface ◽

Skewness And Kurtosis

The surface roughness affects the bone response to dental implants. A primary aim of the roughness is to increase the bone-implant interface shear strength. Surface roughness is generally characterized by means of surface roughness parameters. It was demonstrated that the normally used parameters cannot discriminate between surfaces expected to give a high interface shear strength from surfaces expected to give a low interface shear strength. It was further demonstrated that the skewness parameter can do this discrimination. A problem with this parameter is that it is sensitive to isolated peaks and valleys. Another roughness parameter which on theoretical grounds can be supposed to give valuable information on the quality of a rough surface is kurtosis. This parameter is also sensitive to isolated peaks and valleys. An implant surface was assumed to have a fairly well-defined and homogenous “semiperiodic” surface roughness upon which isolated peaks were superimposed. In a computerized simulation, it was demonstrated that by using small sampling lengths during measurement, it should be possible to get accurate values of the skewness and kurtosis parameters.

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