1-20 of 156 Search Results for

microcrack 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
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002355
EISBN: 978-1-62708-193-1
...; M, matrix; PSB, persistent slip band Abstract This article presents an overview of fatigue crack nucleation from the point of view of the material microstructure and its evolution during cycling. It describes the sites of microcrack nucleation at the free surfaces. The article discusses...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002356
EISBN: 978-1-62708-193-1
... Fig. 6 Growth rates of small and large cracks plotted together as a function of Δ K. CA , constant amplitude. Source: Replotted in Ref 8 from AGARD Report No. 732, 1988 Fig. 7 Subsurface crack nucleation at inclusion, erroneously suggesting initial fast crack growth. Source: Ref 9...
Book Chapter

Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003544
EISBN: 978-1-62708-180-1
... crack nucleation in regions of localized strain and the subsequent crack growth mechanisms outside the plastic zone in the qualification of component designs or to conduct failure analyses. The safe-life, infinite-life philosophy is the oldest of the approaches to fatigue. The design method...
Series: ASM Handbook
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0000603
EISBN: 978-1-62708-181-8
...; and microcrack initiation and propagation. brittle fracture cleavage fracture fatigue cracks fatigue fracture ferritic ductile iron fractographs microcracking pearlitic ductile iron Brittle cleavage fracture of ductile iron spur gear (ASTM A536, grade 100-70-03) due to improper heat treatment...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002409
EISBN: 978-1-62708-193-1
..., and then very slowly cooled. Most of this structure is continuous primary alpha phase and regrowth alpha (that is, alpha that has formed on the preexisting primary alpha phase). The primary alpha existed at the upper temperature and nucleated the regrowth alpha during cooling. This procedure is well established...
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003313
EISBN: 978-1-62708-176-4
... better understanding and simulation of both crack nucleation and the subsequent crack growth mechanisms. This article reviews three basic types of fatigue properties: stress-life, strain life, and fracture mechanic crack growth. crack initiation crack nucleation crack propagation fatigue...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002366
EISBN: 978-1-62708-193-1
... (stage II) normal to the range of maximum principal stress are shown. The curve representing the fraction of life to a 0.1 mm crack is termed “crack nucleation” in Fig. 6(a) and 6(b) , but it actually reflects microcrack propagation to this length. Experimental observations indicate...
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003299
EISBN: 978-1-62708-176-4
..., such as inclusions, grain boundary impurities, second phases, triple junctions, and pores are mainly responsible for the nucleation of microcracks that lead to fracture in ceramics ( Ref 14 , 16 , 17 ). However, the difference in the characteristics of crack growth from these inhomogeneities is mainly responsible...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003565
EISBN: 978-1-62708-180-1
... to the conventional delamination theory ( Ref 24 , 25 ), in which increasing shear deformation, as a result of bodies sliding against one another under load, leads to the piling-up of subsurface dislocations. Under this theory, these cause the nucleation of microcracks, which subsequently lead to the occurrence...
Series: ASM Handbook
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0000610
EISBN: 978-1-62708-181-8
... candy fracture, cleavage fracture, brittle fracture, high-cycle fatigue fracture, fatigue striations, hydrogen-embrittlement failure, creep crack propagation, fatigue crack nucleation, intergranular creep fracture, torsional overload fracture, stress-corrosion cracking, and grain-boundary damage...
Book Chapter

Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003541
EISBN: 978-1-62708-180-1
... deformation events within the resolution of optical and scanning electron microscopy (SEM). Irreversible deformation mechanisms in polymers may fall into two basic categories: dilatational, such as crazes, voids, and microcracks; or nondilatational, such as shear bands. Commonly, a mixture of both mechanisms...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006779
EISBN: 978-1-62708-295-2
... to cyclic stresses of sufficient magnitude. On the microscopic scale, the most important feature of the fatigue process is the nucleation of one or more cracks under the influence of cyclic stresses, followed by the development of microcracks at persistent slip bands within grains or at grain boundaries...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006793
EISBN: 978-1-62708-295-2
... of surface and subsurface crack initiation, and increasing numbers of impact cycles tend to refine the microcrack patterns. Polyoxymethylene is a relatively crystalline polymer; therefore, the conventional delamination theory based on the accumulation of dislocations leading to the nucleation...
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001286
EISBN: 978-1-62708-170-2
... Abstract This article describes eight stages of the atomistic film growth: vaporization of the material, transport of the material to the substrate, condensation and nucleation of the atoms, nuclei growth, interface formation, film growth, changes in structure during the deposition...
Series: ASM Handbook
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0001834
EISBN: 978-1-62708-181-8
... ). The microvoids are nucleated at any discontinuity where a strain discontinuity exists—for example, grain of subgrain boundaries, second-phase particles, and inclusions. These microvoids, shown in Fig. 10 and 11 , are referred to as dimples. Because of the roughness of the dimples, they are best observed...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002352
EISBN: 978-1-62708-193-1
... to fracture. (b) EDS, energy-dispersive spectroscopy. Source: Metals Handbook , 9th ed., Vol 11, p 80 Table 2 Characteristics of the various low-temperature fracture modes Fracture preceded Fracture nucleation Initial crack propagation Final crack propagation Fracture mode...
Series: ASM Handbook
Volume: 2B
Publisher: ASM International
Published: 15 June 2019
DOI: 10.31399/asm.hb.v02b.a0006549
EISBN: 978-1-62708-210-5
... on the plane(s) of stage I (maximum shear) crack propagation. From a macroscopic viewpoint, the stress amplitude normal to the plane of the stage I microcrack in torsional loading is zero, whereas the stress amplitude normal to the shear plane in the uniaxial case is Δσ/4. This results in a significantly lower...
Series: ASM Handbook
Volume: 24
Publisher: ASM International
Published: 15 June 2020
DOI: 10.31399/asm.hb.v24.a0006583
EISBN: 978-1-62708-290-7
... of material produced by conventional PM Tensile/bending strength severely limited by microcracks ++ ++ + Commercial production W ++ ++ + X-ray collimators in production Microparts demonstrated WC-Co Very poor due to high amount of porosity ++ + - Poor microstructure/material properties...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002417
EISBN: 978-1-62708-193-1
... the PSB-matrix interface a prime site for the nucleation of fatigue cracks. Schematics of both mechanisms are shown in Fig. 3 . A few examples have been tentatively identified in real-world ceramics. For instance, the enhanced microcracking zones ahead of fatigue cracks in SiC w -Al 2 O 3 composites...
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003254
EISBN: 978-1-62708-176-4
... ahead of the tip then allows for continued growth of the nucleated voids to the point of instability, as the blunted crack links with the microcrack. This process of microcracking, crack-tip blunting, and failure of the matrix (void formation) between the particles continues as the crack propagates...