Microplastic Relaxations of Single and Polycrystalline Molybdenum

Pichl, W.; Chen, D. L.; Weiß, B.

doi:10.1002/(sici)1521-396x(199805)167:1<43::aid-pssa43>3.0.co;2-e

Cited by 4 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Non-screw dislocations contribute to the slip only in the very early stages of plastic deformation and are exhausted prior to the onset of screw dislocation motion. (This socalled microdeformation regime seems to extend up to a plastic strain of about 2 Â 10 À3 [16].) Extensive investigations on high-purity a-Fe [17] and Ta [18] and ultra-high purity Nb [19], Mo [20] and W [21,22] have verified that the kink-pair model is in excellent agreement with the experimentally observed temperature and strain-rate dependence of the flow stress.…”

Section: Introductionsupporting

confidence: 59%

Slip Geometry and Plastic Anisotropy of Body-Centered Cubic Metals

Pichl

2002

phys. stat. sol. (a)

Self Cite

View full text Add to dashboard Cite

The plastic anisotropy of bcc metals comprises the absence of well-defined slip planes, an orientation dependence of the uniaxial flow stress which seems to be in disagreement with Schmid's law of resolved shear stress, and an asymmetry between tension and compression. Recent theoretical and experimental work has shown that these phenomena are closely correlated to elementary slip on {211} planes in an intermediate temperature range. After a discussion of crystallographic peculiarities of h111i {211} slip, a kinematic model for microscopic cross-slip on triplets of slip planes is proposed which, in combination with the well-established model of thermally activated kink-pair formation, allows quantitative calculations of the plastic anisotropy.

show abstract

Section: Introductionsupporting

confidence: 59%

Slip Geometry and Plastic Anisotropy of Body-Centered Cubic Metals

Pichl

2002

phys. stat. sol. (a)

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the following use is made of a model of Essmann and Mughrabi [44] and of Pichl et al [45] describing behaviours at small and large plastic strains called micro and macro plasticity (or micro and macro yielding). It accounts for the multiplication and annihilation of screw dislocations in Mo in the course of work hardening at room temperature (*0.1T m ).…”

Section: Work Hardeningmentioning

confidence: 99%

Temperature dependence of the plastic flow of high-purity tungsten single crystals

Brunner

2010

International Journal of Materials Research

View full text Add to dashboard Cite

The influence of temperature on the plastic deformation of high-purity tungsten single crystals with an orientation favouring single slip on the (110) or (112) planes, has been studied using tensile tests in the temperature range 26 K to 800 K with emphasis on temperatures below 400 K. The crystals were deformed with an initial applied plastic strain rate of γa = 8.5 · 10−4 s−1 either isothermally until fracture or necking terminated the experiment (called isothermal straining tests) or in small straining intervals at different decreasing temperatures (called isothermal-straining – temperature- lowering tests). After initial plastic deformation at high enough temperatures (T ≥ 650 K; γ ≍ 0.08) tests at lower temperatures (T ≤ 400 K) reveal that the workhardening behaviour changes completely if compared with work-hardening behaviour of tests at the lower temperatures. A combination of tests suggests that work hardening of tungsten cannot be interpreted solely in terms of an increase in the athermal component of the flow stress or an exhaustion of non-screw dislocations. Rather, the results suggest that the different mobilities of screw and non-screw dislocations and their dependence on temperature and strain rate contribute essentially to work hardening at the beginning of plastic flow. Additionally, this is strongly influenced by changes of the slip systems towards the low-temperature regime below about 230 K. Consequences of these features for work hardening and its dependence on temperature, flow stress, critical resolved shear stress are analysed and discussed.

show abstract

“…The high stress dependence of activation volumes in the micro-plastic range resembles that of some bcc materials [4,11]. Though the extremely high values of 10 2 b 3 in bcc metals were not measured here, the Haasen plot of Fig.…”

Section: Discussionmentioning

confidence: 55%

Activation Volume Measurement Techniques: Application to Zircaloy-4

Cuniberti

Picasso

2001

phys. stat. sol. (a)

View full text Add to dashboard Cite

Subject classification: 62.20.-x; S1 Stress relaxation and strain rate change tests were performed in Zircaloy-4 at room temperature. The apparent and effective activation volumes were determined and the results obtained by the different techniques are compared. The stress dependence of activation volumes is studied in a broad range of stresses, and an analysis is made in the light of the thermal activation theory. The results suggest that plasticity is ruled by the overcoming of Peierls barriers.

show abstract

Microplastic Relaxations of Single and Polycrystalline Molybdenum

Cited by 4 publications

References 15 publications

Slip Geometry and Plastic Anisotropy of Body-Centered Cubic Metals

Slip Geometry and Plastic Anisotropy of Body-Centered Cubic Metals

Temperature dependence of the plastic flow of high-purity tungsten single crystals

Activation Volume Measurement Techniques: Application to Zircaloy-4

Contact Info

Product

Resources

About