1-20 of 277 Search Results for

heterogeneous nucleation

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
Image
Published: 01 December 2008
Fig. 9 Comparison between heterogeneous nucleation (A) and homogeneous nucleation (B) in terms of the relative transformation kinetics below the melting point. The reduced temperature T r = T / T f and time t ∝ l −1 . T g , glass transition temperature More
Image
Published: 01 December 2009
Fig. 5 Heterogeneous nucleation at strong defects. Two-dimensional variational solutions to Ginzburg-Landau model for (a) linear elastic material and (b) nonlinear material at onset of martensite mechanical stability. Length scale in units of lattice dislocation Burgers vector, b. Source: Ref More
Image
Published: 01 December 2009
Fig. 6 Heterogeneous nucleation at weak defects. Two-dimensional variational solutions to Ginzburg-Landau model for single lattice dislocation with increasing driving force (a and b), leading to transformed crystal at critical driving force for nucleation in (c). Length scale in units More
Image
Published: 01 December 2009
Fig. 6 Possible shapes of a nucleus in heterogeneous nucleation. (a) Cap shape. (b) Lens shape More
Image
Published: 01 December 2009
Fig. 15 Dislocation process. (a) Concatenated snapshot of a heterogeneously nucleated prismatic dislocation loop gliding through an aluminum thin film. Source: Ref 94 . (b) Microstructural development in a two million atom molecular dynamics simulation of (111) surface indention of aluminum More
Series: ASM Handbook
Volume: 1A
Publisher: ASM International
Published: 31 August 2017
DOI: 10.31399/asm.hb.v01a.a0006311
EISBN: 978-1-62708-179-5
... describes various undercooling methods, including kinetic undercooling, thermal undercooling, constitutional undercooling, and pressure undercooling. For solidification to occur, nuclei must form in the liquid. The article discusses the various types of nucleation: homogeneous nucleation, heterogeneous...
Book: Casting
Series: ASM Handbook
Volume: 15
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.hb.v15.a0005207
EISBN: 978-1-62708-187-0
.... The article describes nucleation phenomenon such as homogeneous nucleation and heterogeneous nucleation. It examines various grain refinement models, such as the carbide-boride model, the free growth model, and the constitutional undercooling model. The article concludes with information on the thermal...
Series: ASM Handbook
Volume: 9
Publisher: ASM International
Published: 01 December 2004
DOI: 10.31399/asm.hb.v09.a0003731
EISBN: 978-1-62708-177-1
... Abstract Precipitation reactions occur in many different alloy systems when one phase transforms into a mixed-phase system as a result of cooling from high temperatures. This article discusses the homogenous and heterogeneous nucleation and growth of coherent and semicoherent precipitates...
Image
Published: 01 January 1993
speed are not yet sufficient to cause heterogeneous nucleation at the weld pool centerline. (c) High heat input and high welding speed, with heterogeneous nucleation at the weld pool centerline. Source: Ref 13 More
Image
Published: 31 October 2011
Fig. 8 Comparison of free-energy changes associated with homogeneous nucleation, heterogeneous nucleation, and fusion welding More
Image
Published: 01 January 1986
Fig. 60 Dislocation/precipitate images in olivine. (a) and (b) Small nonplanar precipitates heterogeneously nucleated on a dislocation. (c) and (d) Coarser heterogeneous precipitates on a dislocation. In (a) and (c), the [001] dislocations are out of contrast, g = (100); in (b) and (d More
Image
Published: 01 December 2008
Fig. 12 The bold curve indicates the undercooling necessary for grain initiation. The free-growth undercooling is calculated; the nucleation undercooling is schematic only. Inset (i) shows the classical spherical cap model for heterogeneous nucleation. Inset (ii) shows a cap of α-aluminum More
Image
Published: 01 December 2009
Fig. 2 System diagram for the dynamic structural hierarchy for heterogeneous nucleation of martensite More
Image
Published: 01 December 2009
. (b) A condition involving recovery, heterogeneous nucleation at sites of high stored energy, and anisotropic grain-boundary (GB) properties. MCS, Monte Carlo steps. Source: Ref 42 More
Series: ASM Handbook
Volume: 3
Publisher: ASM International
Published: 27 April 2016
DOI: 10.31399/asm.hb.v03.a0006222
EISBN: 978-1-62708-163-4
.... This process of forming nuclei in the freezing melt and their subsequent growth is characterized as a nucleation and growth process. Fig. 13 Nucleation and growth during solidification. Source: Ref 2 Nucleation can occur by either homogeneous or heterogeneous nucleation. Homogenous nucleation...
Book: Casting
Series: ASM Handbook
Volume: 15
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.hb.v15.a0005222
EISBN: 978-1-62708-187-0
... nucleation of pores is extremely difficult and is unlikely to occur in practice. Heterogeneous Nucleation In castings, nucleation of pores can be expected to occur primarily at heterogeneous nucleation sites. The classical theory of homogeneous nucleation is extended to heterogeneous nucleation...
Book: Casting
Series: ASM Handbook
Volume: 15
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.hb.v15.a0005211
EISBN: 978-1-62708-187-0
... of these alloys, the first eutectic solid forms by heterogeneous nucleation, and the second solid nucleates contiguously and heterogeneously but may not necessarily nucleate on the first solid phase. In Fig. 5 , regions marked 1 and 2 are termed normal or regular eutectic structures and constitute structures...
Series: ASM Handbook
Volume: 6
Publisher: ASM International
Published: 01 January 1993
DOI: 10.31399/asm.hb.v06.a0001338
EISBN: 978-1-62708-173-3
... . There are three ways in which a solid can form: homogeneous nucleation, heterogeneous nucleation, and epitaxial growth. Homogeneous nucleation occurs when there is no foreign body (mold wall, solid particle in the melt, etc.) on which to form the solid. Figure 2 shows the balance of the surface tension...
Series: ASM Handbook
Volume: 4E
Publisher: ASM International
Published: 01 June 2016
DOI: 10.31399/asm.hb.v04e.a0006250
EISBN: 978-1-62708-169-6
.... annealing castings deformation diffusion coefficient grain growth heat treatment heterogeneous nucleation homogeneous nucleation homogenization isothermal transformation nonferrous metals precipitation hardening recrystallization recrystallization temperature solid-state phase transformation...
Book: Casting
Series: ASM Handbook
Volume: 15
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.hb.v15.a0005213
EISBN: 978-1-62708-187-0
... undercoolings are much smaller than required by the theory of homogeneous nucleation (1 to 10 °C, or 2 to 20 °F, as opposed to 230 °C, or 415 °F). Nevertheless, some C n clusters (as discussed earlier in this section) or undissolved graphite may act as heterogeneous nuclei for graphite formation. When two...