Physico-Chemical Phenomena in the Deformation of Metals

Likhtman, V. I.; Shchukin, Eugenii D

doi:10.1070/pu1958v001n01abeh003087

Cited by 20 publications

(11 citation statements)

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“…for a-brass in HgL by Edmunds (194), Nichols and Rostoker (1961), and Rosenberg and Cadoff (1963), and for in BiL -18 -by Morgan (1954). On the other hand, Likhtman and Shchukin (1958), and Shchukin et al (1959) have reported that Zn monocrystals, oriented for single slip, can be significantly embrittled by 1gL or GaL. According to Likhtman and Shchukin (1958), the room temperature stress and strain at fracture of 1mm dia.…”

Section: Mechanical Factfrsmentioning

confidence: 99%

“…On the other hand, Likhtman and Shchukin (1958), and Shchukin et al (1959) have reported that Zn monocrystals, oriented for single slip, can be significantly embrittled by 1gL or GaL. According to Likhtman and Shchukin (1958), the room temperature stress and strain at fracture of 1mm dia. crystals of orientation X = 48 v•-ere respectively reduced from -1400 gm/mmý and 260% 0 in air, to -200 gm/mm2 and 10% in HgLV fig.…”

Section: Mechanical Factfrsmentioning

confidence: 99%

See 1 more Smart Citation

Adsorption-Induced Brittle Fracture in Liquid-Metal Environments

Westwood¹,

Preece²,

Kamdar³

1971

Engineering Fundamentals and Environmental Effects

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Section: Mechanical Factfrsmentioning

confidence: 99%

Section: Mechanical Factfrsmentioning

confidence: 99%

Adsorption-Induced Brittle Fracture in Liquid-Metal Environments

Westwood¹,

Preece²,

Kamdar³

1971

Engineering Fundamentals and Environmental Effects

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“…Rehbinder and coworkers ( Rehbinder 1957, Likhtman et al 1964 recognized that interfacial tension need not actually be negative for spontaneous dispersion to occur. It is necessary only that tension be low enough that the free energy decrease (due to the entropy of dispersion) outweigh the increase in interfacial free energy (due to dispersion).…”

Section: Conclusion and Significancementioning

confidence: 98%

Thermodynamics of microemulsions: Combined effects of dispersion entropy of drops and bending energy of surfactant films

Miller

Neogi

1980

AIChE Journal

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so that the criterion for smau composition gradients becomes -B ' < < 1 (A61 According to ( A 2 ) the condition (A6) also insures small relative pressure gradients. To examine the conditions under which ( A 6 ) is valid, we take the following example: T = 800"K, R, = 50 pm, €4 = 0.015, weight loss = 20% in 10 s (half of which is gases and half is tar). Using molecular weights MG = 25, MT = 250 and coal particle density 1.2 g/cm3, we compute YG = 4.8 x gmols/cm%, YT = 0.48 x 10-4 gmols/ cm%, DGK = 2.74 a$/,, DTG = 0.48 cm2/s, f = 0.33, S = 0.1 so that = 0.015. On the other hand, taking T = 900°K the rates are larger by a factor 3-5 so thatB' -0.01-0.08. If, on the other hand, we take T = 900°K and R, = 100 pm, -0.06-0.11, -0.16-0.34, marking a departure from uniform conditions. Under conditions at which B' <$ 1, the use of an effective radius as defined by Equation ( 5 ) P. NEOGIA theory of dilute microemulsions is presented which includes for the first time both the entropy of dispersion of the drops and energy effects associated with bending the surfactant films at the drop interfaces. It yields expressions for drop size for (a) a dilute microemulsion in equilibrium with an excess bulk phase, e.g., an oil-in-water microemulsion in equilibrium with excess oil and (b) dilute oil-continuous and water-continuous microemulsions in equilibrium and containing equal amounts of surfactant. In the latter case, our theory indicates that existence of the two microemulsion phases sometimes is favored over a layered or lamellar phase, even though the "natural curvature" of the surfactant films is zero, corresponding to a perfectly flat f i l m . Department of Chemical EngineeringCarnegie-Mellon University Pittsburgh, Pennsylvania 15213 SCOPE "Microemulsions are dispersions of one liquid in another which have very small drops (< 0.1 pm) and are often thermodynamically stable. They have been used in such applications as cutting oils and pesticides and are currently of great interest in connection with processes for increasing recovery of petroleum from underground reser- voirs.An important property of a microemulsion is its drop size. Existing theory indicates that drop size has a large P. Neogi i c present11 at the St'itc University of New York, Buffalo,

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“…[80] Such results have been reported earlier. [26][27][28] Since plastic deformation accompanies the embrittlement as indicated by the significant fracture strain (Figure 17), we have plasticity-or dislocation-induced local cleavage, as evidenced by the ''shear-band failure'' observed in these materials (Figure 18(a)). Intergranular and cavity nucleation and coalescence modes of crack growth were also noticed (Figures 18(b) and (c)).…”

Section: B Crack Growth Behavior and Fractographic Analysismentioning

confidence: 99%

“…[26][27][28] That is, the stress-strain curves are almost identical other than the reduction in the fracture strain in the presence of a liquid metal. In essence, the yield stress and strain hardening are unaffected by the environment other than the stress (strain) necessary for crack initiation and growth.…”

Section: A Crack Nucleationmentioning

confidence: 99%

Review of Environmentally Assisted Cracking

Sadananda

Vasudévan

2010

Metall Mater Trans A

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Many efforts have been made in the past by several researchers to arrive at some unifying principles governing the embrittlement phenomena. An inescapable conclusion reached by all these efforts was that the behavior is very complex. Hence, recognizing the complexity of material/environment behavior, we focus our attention here only in extracting some similarities in the experimental trends to arrive at some generic principles of behavior. Crack nucleation and growth are examined under static load in the presence of internal and external environments. Stress concentration, either pre-existing or in-situ generated, appears to be a requirement for embrittlement. A chemical stress concentration factor is defined for a given material/environment system as the ratio of failure stress with and without the damaging chemical environment. All factors that affect the buildup of the required stress concentration, such as planarity of slip, stacking fault energy, etc., also affect the stress-corrosion behavior. The chemical stress concentration factor is coupled with the mechanical stress concentration factor. In addition, generic features for all systems appear to be (a) an existence of a threshold stress as a function of concentration of the damaging environment and flow properties of the material, and (b) an existence of a limiting threshold as a function of concentration, indicative of a damage saturation for that environment. Kinetics of crack growth also depends on concentration and the mode of crack growth. In general, environment appears to enhance crack tip ductility on one side by the reduction of energy for dislocation nucleation and glide, and to reduce cohesive energy for cleavage, on the other. These two opposing factors are coupled to provide environmentally induced crack nucleation and growth. The relative ratio of these two opposing factors depends on concentration and flow properties, thereby affecting limiting thresholds. The limiting concentration or saturation depends on the relative chemistry of environment and material. A dynamic dislocation model is suggested to account for crack growth.

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Physico-Chemical Phenomena in the Deformation of Metals

Cited by 20 publications

References 0 publications

Adsorption-Induced Brittle Fracture in Liquid-Metal Environments

Adsorption-Induced Brittle Fracture in Liquid-Metal Environments

Thermodynamics of microemulsions: Combined effects of dispersion entropy of drops and bending energy of surfactant films

Review of Environmentally Assisted Cracking

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