1-20 of 134

Search Results for diffusional flow

Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0004020
EISBN: 978-1-62708-185-6
..., followed by the models of constitutive behavior. It provides a discussion on creep mechanisms involving dislocation and diffusional flow, such as the Nabarro-Herring creep and the Coble creep. The equations for the several creep rates are also presented. Research on the mechanism of the superplastic flow...
Series: ASM Handbook
Volume: 14B
Publisher: ASM International
Published: 01 January 2006
DOI: 10.31399/asm.hb.v14b.a0005183
EISBN: 978-1-62708-186-3
... creep mechanisms that are useful for illustrating the strong stress dependence of dislocation and diffusional flow. ambient temperature Isothermal constitutive modeling physical models strain hardening strain-rate-sensitive flow superplastic flow CONSTITUTIVE RELATIONS for metalworking...
Image
Published: 01 December 1998
Fig. 45 Deformation-mechanism maps for (a) thoria-dispersed nickel and (b) type 316 stainless steel. Diffusional flow is a type of creep that occurs at very high temperatures and very low stresses. More
Image
Published: 01 January 2006
Fig. 24 During the intermediate stage of grain switching, grains 1 and 2 (compare with Fig. 23 ) change their shape from that indicated by the solid (initial state) lines to that of the dotted lines. The shape change is provided for by diffusional flow, which can take place by volumetric More
Image
Published: 01 January 2005
Fig. 24 During the intermediate stage of grain switching, grains 1 and 2 (compare with Fig. 23 ) change their shape from that indicated by the solid (initial state) lines to that of the dotted lines. The shape change is provided for by diffusional flow, which can take place by volumetric More
Image
Published: 01 January 1987
), air cool. Sample was tensile tested to failure at 700 °C (1290 °F) and an initial strain rate of 4.4 × 10 −5 /s. Slip lines, smoothened by diffusional flow, are visible on grain boundaries of the elevated-temperature fracture surface. Failure was intergranular and resulted from the nucleation, growth More
Book: Casting
Series: ASM Handbook
Volume: 15
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.hb.v15.a0005226
EISBN: 978-1-62708-187-0
..., and the formation of noncrystalline phases. It considers three factors to understand the fundamentals of these changes: heat flow, thermodynamic constraints/conditions at the liquid-solid interfaces, and diffusional kinetics/microsegregation. These factors are described in detail. casting microsegregation...
Book Chapter

By Sammy Tin
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005404
EISBN: 978-1-62708-196-2
... diffusional flow can be derived by first considering the equilibrium concentration of vacancies, C , within a material: (Eq 30) C = C o   exp ( − Q f k T ) where Q f is the vacancy formation energy, and C o is the equilibrium vacancy concentration coefficient. Upon...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005458
EISBN: 978-1-62708-196-2
... it. Subsequently, cavity-growth models were developed; these analyses focused on stress concentrations along the grain boundaries, with diffusional flow relaxing tensile stresses at cavity tips on the grain boundary and higher tensile stresses developing in regions between cavities. This leads to higher vacancy...
Image
Published: 01 December 2009
Fig. 8 Schematic showing the flow of atoms from compressive boundaries to tensile boundaries during diffusional Nabarro-Herring creep. Vacancy flow occurs in the direction opposite to that of the atom flow. More
Image
Published: 01 January 2003
Fig. 9 The Wang-Seigle model for aluminum transport incorporating diffusional flux and viscous flow in the depleted zone. Source: Ref 20 More
Image
Published: 01 January 1997
Fig. 29 Diffusional creep results from a higher vacancy concentration in regions of a material that experience a tensile stress compared to regions that do not. This results in a vacancy flux from the former to the latter areas, and a mass flux in the opposite direction. This extends More
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005433
EISBN: 978-1-62708-196-2
... and classical physical constitutive equations. The article also reviews the accommodation mechanisms that are divided into two major groups, namely, diffusional accommodation and accommodation by dislocations. constitutive model superplastic flow superplasticity phenomenological constitutive equation...
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003287
EISBN: 978-1-62708-176-4
... present compelling evidence that dislocations interact strongly with particles on a very local scale. Deformation Mechanism Maps The mechanisms of dislocation glide, dislocation climb, and diffusional flow exhibit different stress and temperature dependencies. Thus, the relative contribution...
Series: ASM Handbook Archive
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0000601
EISBN: 978-1-62708-181-8
... cool. Sample was tensile tested to failure at 700 °C (1290 °F) and an initial strain rate of 4.4 × 10 −5 /s. Slip lines, smoothened by diffusional flow, are visible on grain boundaries of the elevated-temperature fracture surface. Failure was intergranular and resulted from the nucleation, growth...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005409
EISBN: 978-1-62708-196-2
... by grain-boundary sliding accommodated by glide/climb of dislocations, m ∼ 0.5 and p ∼ 2. For grain-boundary sliding accommodated by diffusional flow, m ∼ 1 and p ∼ 2 or 3, depending on whether bulk (lattice) or boundary diffusion predominates. It has been shown that superplastic flow in two...
Series: ASM Handbook
Volume: 4B
Publisher: ASM International
Published: 30 September 2014
DOI: 10.31399/asm.hb.v04b.a0005966
EISBN: 978-1-62708-166-5
... along a concentration gradient , from higher concentration to lower concentration. If the concentration gradient is maintained or stable, then the flow or flux is maintained. If the diffusional flow reduces the gradient, then the flux diminishes as diffusion proceeds. For a given direction...
Series: ASM Handbook
Volume: 6A
Publisher: ASM International
Published: 31 October 2011
DOI: 10.31399/asm.hb.v06a.a0005606
EISBN: 978-1-62708-174-0
... of this class of material. Research since 1960 has demonstrated only limited diffusion bond properties. Although interface strength can be increased for oxide-bearing materials, it requires considerable surface extension of the faying interfaces to create localized plastic flow of the metal and concurrent oxide...
Series: ASM Handbook
Volume: 6
Publisher: ASM International
Published: 01 January 1993
DOI: 10.31399/asm.hb.v06.a0001350
EISBN: 978-1-62708-173-3
... alloys are prime examples of this class of material. Research since 1960 has demonstrated only limited diffusion bond properties. Although interface strength can be increased for oxide-bearing materials, it requires considerable surface extension of the faying interfaces to create localized plastic flow...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005425
EISBN: 978-1-62708-196-2
... models that can and are used to predict future applications of the studied process. Figure 1 shows a schematic flow path for the development of models that provide improved understanding of processes, where metallurgical or manufacturing process-based. Fig. 1 Process flow for development...