Mechanical behavior of crystalline solids at elevated temperature

Sherby, O. D.; Burke, P.

doi:10.1016/0079-6425(68)90024-8

Cited by 826 publications

(337 citation statements)

References 65 publications

Supporting

Mentioning

317

Contrasting

Unclassified

Order By: Relevance

“…15,16) It is generally accepted that the rate-controlling mechanism for 5-power law creep is associated with slip creep where the controlled step is due to dislocation climb at pile-ups. 17) Subgrains have been reported to form during deformation under this mechanism at temperatures above 700°C. 18,19) The size of these subgrains, l s , resulting from this type of creep, is strongly dependent on stress and is independent of the temperature and the steady state-creep strain.…”

Section: Discussionmentioning

confidence: 99%

High Temperature Mechanical Behavior of a 30%Ni-19%Cr Steel

et al. 2003

View full text Add to dashboard Cite

The deformation behavior at high temperature of a Type 800 Incoloy alloy reinforced by TiC particles was investigated by tensile and torsion tests at temperatures ranging from 800 to 1 200°C. The as-received material exhibited a microstructure of coarse equiaxic grains with subgrains decorated by small TiC particles. The material showed an activation energy for plastic flow of 400 kJ/mol similar to the activation energy for lattice diffusion in austenitic stainless steels. The stress exponents varied strongly with testing conditions. After testing at temperatures up to 1 000°C, the initial austenitic grains were elongated in the tensile direction, but the subgrain structure did not change with stress. In contrast, a microstructural refinement was observed after tensile testing at 1 100°C, which was associated with a process of dynamic recrystallization that occurs during deformation. At this temperature the deformation behavior of the material can be described by a slip creep mechanism. At the rest of the test temperatures the controlling mechanism is that of constant-structure slip creep.KEY WORDS: iron-base superalloy; microstructure; high temperature mechanical behaviour; constant structure creep.cidate the controlling deformation mechanism, the investigation was completed with a detailed microstructural analysis of the as received and deformed materials. Experimental ProcedureThe as-received material was supplied as a bar of 400 mm, which was prepared by hot rolling a bar of 600 mm in diameter heated to 1 200°C for 45 min and then air cooled. The chemical composition of the alloy used in the present study was determined by Inductively Coupled Plasma, except for nitrogen and carbon that were determined by infrared absorption after combustion in an induction furnace. The composition was the following (wt%): 30Ni-19Cr-0.8Mn-0.5Al-0.5Ti-0.45Si-0.12C-0.01N, balance Fe.The microstructures of the as-received material and after deformation were studied by optical microscopy, and scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX) microanalysis. Metallographic preparation included mounting the samples in baquelite and polishing by the conventional method. The microstructure was revealed by etching at room temperature with a solution of 45 mL of HCl, 15 mL of HNO 3 and 20 mL of distilled water.Elevated temperature mechanical properties were characterized by tensile and torsion tests. The tensile tests were performed at strain rates ranging from 3ϫ10 Ϫ6 to 2ϫ 10 Ϫ3 s Ϫ1 in the temperature range 800 to 1 100°C. Tensile samples with a rectangular cross section of 3ϫ5 mm and a gage length of 20 mm were machined in the direction parallel to the bar axis. In order to minimize the effect of oxidation, tensile tests were performed under a protective argon atmosphere. True tensile strains, stresses and strain rates were calculated from the load-deformation curves with the assumption of uniform deformation and conservation of volume.Hot torsion tests were performed at equivalent strain rates ranging f...

show abstract

Section: Discussionmentioning

confidence: 99%

High Temperature Mechanical Behavior of a 30%Ni-19%Cr Steel

et al. 2003

View full text Add to dashboard Cite

show abstract

“…La aparición en este ámbito de la ecuación de Garofalo se produce cuando los investigadores van aumentando los recorridos en tensiones de trabajo, velocidades de deformación y temperaturas, y cuando observan que las técnicas de reducción y los tratamientos matemáticos tradicionales conducen a problemas insolubles (7)(8)(9)(10)(11). Se postula la ecuación de Garofalo, en principio heurísticamente, después fenomenológicamente (12) y cada día más con soporte de modelos físicos (3), para resolver los problemas que plantean los resultados experimentales para amplios recorridos de las variables.…”

Section: Introductionunclassified

Capacidad de predicción de esfuerzos de conformado de materiales metálicos. Aplicación a la aleación Ti-6Al-4V

Rieiro¹,

Martínez²,

Carsí³

1998

REVMETAL

View full text Add to dashboard Cite

“…It sho uld be noted th at Sj is also referred to as an internal state variabl e in the plasticity literature. A more genera l fo rmul ati on ca n expres the ten orial creep rate, E mn , in term of a tensori al stress state, (Jllln ' The role of micro tructure in influencing creep behavior has been studied extensively in a large number of materi als as evidenced by the numerous review arti cles (Schoeck , 1957 ;Sherby, L 962;M cLean, 1966;Sherby and Burke, 1967;Lag neborg, 1972;Weertman , 1975 ;Takeuch i and Argon , 1976;Blum, 1977;Nix and I1schner, ] 980; M ys hl yaev , 198 1; Bendersky et a !., 1985; Nix and Gibe ling, I 985(a); Cadek, 1986: Ca ill ard andB lum et a!. , 199 1;Longquan and N orthwood , 1993 ;Yoshin aga, 1993;Raj , 1994) and text (Garofalo, J965 ;Gittu , 1975 ;Poirier, 1985) which have followed the course of development of the subject over the last four decades.…”

Section: Kinetic and Microstructure Evolution Lawsmentioning

confidence: 99%

“…Indeed , as shown in Tab le II (Raj and Langdon , 1991 (b» , this appear to be the ca e when the values of T are compared with nGb for AI, Cu and Sn, but c it i cauti oned that more experimenta l data are required to co nfirm thi trend. Th ird, the Sherbt Burke criteri o n, which predicts that th~fower-I aw breaks down at an alm ost constant va lue of UD I '" 10 13 m-(or equi va lentl y, (€ kTJD,Gb)I:2 B =: 10 ) (Sherby and Burke, 1967), appears to be va lid onl y for hi gh stac king fa ult energy ma teri als (r> ISOJm )( Fig. 12) (Raj, 1986).…”

Section: Power-law Breakd Own Criterionmentioning

confidence: 99%