Dynamic axial crushing of combined composite aluminium tube: the role of both reinforcement and surface treatments

2002 ◽  
Vol 56 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J Bouchet ◽  
E Jacquelin ◽  
P Hamelin
Keyword(s):  
Surface Treatments ◽  
Axial Crushing

scholarly journals Role of Plasma Surface Treatments on Wetting and Adhesion

Engineering ◽  
2010 ◽  
Vol 02 (06) ◽  
pp. 397-402 ◽  
Author(s):  
Rory Wolf ◽  
Amelia Carolina Sparavigna
Keyword(s):  
Surface Treatments ◽  
Plasma Surface

Paper 4: Effect of Environment on Bearing Performance

1967 ◽  
Vol 182 (10) ◽  
pp. 116-123
Author(s):  
D. Scott
Keyword(s):  
Adverse Effects ◽  
Relative Motion ◽  
Environmental Effects ◽  
Material Properties ◽  
Failure Mechanisms ◽  
Surface Treatments ◽  
Dominant Effect ◽  
Specific Mechanism ◽  
Lubricant Property

The life of bearings, components which allow relative motion between members of a mechanism, is greatly dependent upon the properties of the materials of construction, but the nature of the lubricant and the environment can have a dominant effect on the incidence of failure. Lubricant contamination and degradation can be deleterious. Additives which impart or reinforce some lubricant property desirable for a specific mechanism may be detrimental to other moving mechanisms. Water in lubricant, not adequately additive fortified, may be harmful. Solid additives such as MoS2 can be beneficial if used correctly. Incompatibility with other additives may have adverse effects. The role of material properties and surface treatments in counteracting deleterious lubricant effects is discussed. Aspects of specific environmental effects as well as failure mechanisms in general are dealt with.

scholarly journals Relation between the Mechanical Behaviour of a High Strength Steel and the Microstructure in Gigacycle Fatigue

2010 ◽  
Vol 636-637 ◽  
pp. 1459-1466 ◽  
Author(s):  
Zhi Yong Huang ◽  
Wei Wei Du ◽  
Danièle Wagner ◽  
Claude Bathias
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Inclusion Size ◽  
Fatigue Behaviour ◽  
Surface Treatments ◽  
Compressive Stresses ◽  
Material Fatigue ◽  
Railway Industry ◽  
Carburizing Process

Many components can reach or exceed 109 cycles in their service time. When fatigue life is beyond 106, the Wöhler S-N curve was always considered to be asymptotic in horizontal axis, but the fatigue behaviour over 106 cycles can not be neglected. It is not usual to carry out a fatigue test beyond 109 cycles due to the conventional fatigue test’s constraints, time consuming and expensive. High strength steel is widely applied in automobile, railway industry after surface treatment in order to improve performance of material in practice. Carburizing process hardens surface to increase wear and fatigue resistance and shot peening has a beneficial effect on the material fatigue strength from the surface residual compressive stresses. A piezoelectric gigacycle fatigue machine is used to do the tests in gigacycle regime on specimens with different surface treatments. The effect of different surface treatments is investigated in gigacycle regime at a frequency of 20KHz with a fixed stress ratio R=0.1 at room temperature. Moreover, Scanning Electron Microscopy (SEM) observations of fracture surfaces are analyzed to evaluate the mechanism of damage related to surface treatments, microstructure scored inclusion size. The role of inclusions and microstructure is emphasized at 109 cycles.

Substrate Surface Treatments and “Controlled Contamination” in GaN / Sapphire MOCVD

1997 ◽  
Vol 482 ◽  
Author(s):  
Yuval Golan ◽  
Paul Fini ◽  
Steven P. Denbaars ◽  
James S. Speck
Keyword(s):  
Substrate Surface ◽  
Chemical Vapor ◽  
Surface Treatments ◽  
Organic Chemical ◽  
Oxide Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Organic ◽  
Common Substrate

AbstractWe have used atomic force microscopy (AFM) to study the effect of common substrate surface treatments for the metal-organic chemical vapor deposition (MOCVD) of GaN on sapphire. It appears that contaminants play a major role in the surface chemistry and strongly influence the morphology of the treated surfaces. In order to investigate the role of these contaminants, we have introduced the concept of “controlled contamination” (CC), namely, exposure of the sapphire surfaces to controlled amounts of potential contaminants in-situ and investigation of the resulting sapphire morphology. The results showed that sapphire, considered to be a very stable oxide surface, is clearly reactive in the GaN MOCVD chemical environment at the high temperatures (HT) employed, allowing us to use CC for obtaining sapphire substrates with controlled roughness. Nevertheless, epitaxial growth using the two-step GaN MOCVD process appears to be very robust and practically insensitive to the (submicronscale) substrate morphology.

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