Ductility limit diagrams for superplasticity and forging of high temperature polycrystalline materials

Published on Aug 1, 2020in Acta Materialia7.656
· DOI :10.1016/J.ACTAMAT.2020.04.050
Wei Zhang5
Estimated H-index: 5
(UT: University of Tennessee),
Wei Zhang132
Estimated H-index: 132
(UT: University of Tennessee)
+ 5 AuthorsLiang Jiang13
Estimated H-index: 13
(Yantai University)
Sources
Abstract
Abstract A mechanistic understanding of the ductility limit diagrams is of critical importance, but it still remains elusive for a multitude of high temperature materials processing techniques, such as superplastic forming and hot forging. The relevant failure modes for the former are necking at high strain rates and intergranular cavitation at low strain rates, while those for the latter include the competition between longitudinal fracture and shear band. The comparison between the Arrhenius processes for grain boundary diffusion and grain interior creep defines a length scale that dictates whether the grain boundary cavity growth is diffusive or creep-constrained. A quantitative assessment of these damage evolution processes leads to the delineation of the dominant parametric spaces for individual failure modes, and thus superplasticity and forging limit diagrams are derived and compared to available experiments in literature.
📖 Papers frequently viewed together
1 Citations
119 Citations
7 Citations
References27
Newest
#1Wei Zhang (UT: University of Tennessee)H-Index: 5
#1Wei Zhang (UT: University of Tennessee)H-Index: 132
Last. Zhili Feng (ORNL: Oak Ridge National Laboratory)H-Index: 33
view all 6 authors...
Abstract Creep strength enhanced ferritic (CSEF) steels containing 9-12wt% chromium have been extensively used in fossil-fuel-fired power plants. Despite their excellent creep resistance at high temperatures, premature failures (especially Type IV cracking) are often found in the fine-grained heat affected zone (HAZ) or intercritical HAZ of the welded components. This failure mode is preceded by the strain localization in the HAZ, as measured by the Digital Image Correlation (DIC) technique. The...
12 CitationsSource
#1Wei Zhang (UT: University of Tennessee)H-Index: 132
#1Wei Zhang (UT: University of Tennessee)H-Index: 5
Last. Zhili Feng (ORNL: Oak Ridge National Laboratory)H-Index: 33
view all 6 authors...
Abstract The creep rupture behavior (Type IV failure) for weldments of creep strength enhanced ferritic steel is numerically analyzed, using an integrated microstructure- and micromechanics-based finite element model. To account for the large microstructure gradients across weldments, a two-dimensional digital microstructure is constructed based on the actual observed microstructure of ferritic steel weldment by using the Voronoi-tessellation method. According to the fracture mechanism studies a...
8 CitationsSource
#1Xin Wang (CSU: Central South University)H-Index: 4
#2Zaiwang Huang (CSU: Central South University)H-Index: 16
Last. Liang Jiang (CSU: Central South University)H-Index: 13
view all 9 authors...
Abstract Controlling the final grain size in a uniform manner in powder metallurgy nickel-based superalloys is important since a number of mechanical properties are closely related to it. However, it has been widely documented that powder metallurgy superalloys are prone to suffer from growth of abnormally large grains (ALGs) during supersolvus heat treatment, which is harmful to in-service mechanical performance. The underlying mechanisms behind the formation of ALGs are not yet fully understoo...
20 CitationsSource
#1Guoai HeH-Index: 11
#2Feng LiuH-Index: 13
Last. Liang JiangH-Index: 13
view all 4 authors...
Hot compression tests on a newly designed hot extrusion Nickel-based powder metallurgy superalloy are conducted at various deformation conditions. The contact friction coefficient (f) between the die and forged part is determined as 0.30–0.40 by analyzing the results of simulation and the real experiment. A new coefficient B is introduced to evaluate the bulging levels and relate the value of f. The critical strains to prevent peripheral cracks are found to relate closely to the processing param...
13 CitationsSource
#1Minqiang Jiang (CAS: Chinese Academy of Sciences)H-Index: 25
#2Gerhard WildeH-Index: 58
Last. Lanhong Dai (CAS: Chinese Academy of Sciences)H-Index: 34
view all 7 authors...
At temperatures well below the glass transition temperature, the failure of metallic glasses is generally induced by shear banding, which is a result of the self-organized shear transformation zones (STZs). Here, we demonstrate that, upon cooling down to liquid helium temperature (4.2 K), a Zr-based bulk metallic glass under quasi-static uniaxial tension can fracture via cavitation, rather than by shear banding, showing a transition from shear- to dilatation-dominated failure. This transition is...
32 CitationsSource
#1Yanchun Zhu (NPU: Northwestern Polytechnical University)H-Index: 5
#2Weidong Zeng (NPU: Northwestern Polytechnical University)H-Index: 32
Last. Kaixuan WangH-Index: 7
view all 6 authors...
Abstract It is well known that once plastic deformation reaches a certain limit, metal materials may undergo ductile fracture, which will affect the workability of engineering materials. The accurate prediction of a material ductile fracture is thus of practical importance in the optimization of processes and improvement of products. The knowledge of the strain paths at a critical fracture site of a deforming material is helpful to study the detailed mechanics in the workability. Therefore, an a...
25 CitationsSource
#1Yanfei Gao (UT: University of Tennessee)H-Index: 38
#2Lu Wang (UT: University of Tennessee)H-Index: 4
Last. T.G. Nieh (UT: University of Tennessee)H-Index: 86
view all 4 authors...
Abstract This paper shows that it is inappropriate to relate the angle between the loading axis and the shear-band (or fracture) plane in metallic glasses under uniaxial loading conditions to the coefficient of internal friction in the Mohr–Coulomb model. Shear bands in metallic glasses are a result of material instability (which can be predicted from constitutive parameters and loading conditions), which does not correspond to the material yield condition. Specifically, the shear-band direction...
50 CitationsSource
#1Caijun SuH-Index: 4
#2James A. LaManna (UT: University of Tennessee)H-Index: 2
Last. George M. Pharr (UT: University of Tennessee)H-Index: 84
view all 5 authors...
Deformation behavior of amorphous selenium near its glass transition temperature (31 C) has been investigated by uniaxial compression and nanoindentation creep tests. Cylindrical specimens compressed at high temperatures and low strain rates deform into drum-like shape, while tests at low temperatures and high strain rates lead to fragmentation. These results agree nicely with the stress exponent and kinetic activation parameters extracted from the nanoindentation creep tests by using a similari...
12 CitationsSource
#1Fujio AbeH-Index: 52
#2Torsten-Ulf KernH-Index: 1
Last. Ramaswamy ViswanathanH-Index: 4
view all 3 authors...
Part 1 General: Introduction The development of creep-resistant steels Specifications for creep-resistant steels: Europe Specifications for creep-resistant steels Production of creep-resistant steels for turbines. Part 2 Behaviour of creep-resistant steels: Physical and elastic behaviour of creep-resistant steels Diffusion behaviour of creep-resistant steels Fundamental aspects of creep deformation and deformation mechanism map Strengthening mechanisms in steel for creep and creep rupture Precip...
190 CitationsSource
#1Jason R. Trelewicz (MIT: Massachusetts Institute of Technology)H-Index: 15
#2Christopher A. Schuh (MIT: Massachusetts Institute of Technology)H-Index: 78
Abstract The deformation behavior of nanocrystalline Ni–W alloys is evaluated by nanoindentation techniques for grain sizes of 3–150 nm, spanning both the range of classical Hall–Petch behavior as well as the regime where deviations from the Hall–Petch trend are observed. The breakdown in strength scaling, observed at a grain size of 10–20 nm, is accompanied by a marked transition to inhomogeneous, glass-like flow (i.e. shear banding) at the finest grain sizes approaching the amorphous limit. As...
211 CitationsSource
Cited By5
Newest
#1Xue Wang (UT: University of Tennessee)H-Index: 3
view all 3 authors...
Source
#1Vaclav Sklenicka (CAS: Academy of Sciences of the Czech Republic)H-Index: 18
#2Petr Král (CAS: Academy of Sciences of the Czech Republic)H-Index: 44
Last. Luboš Kloc (CAS: Academy of Sciences of the Czech Republic)H-Index: 11
view all 6 authors...
Abstract The objective of the present study was to provide new relevant information on creep behaviour and fracture processes in a sponge-based modified Zr1%Nb cladding alloy (modified E110 alloy) in the α-Zr and (α+β)-Zr phase regions. To this end, constant load creep tests were carried out in argon at testing temperature intervals from 350°C to 950°C, and applied tensile stresses ranging from 5 MPa to 210 MPa, corresponding to the power-law breakdown creep regime and/or high testing temperatur...
Source
An investigation of flow behavior and the deformation mechanism for Ti-6Al-4V alloy during the superplastic deformation process is presented in this paper. Constant strain rate tensile tests were performed at 890–950 °C and strain rates of 10−2, 10−3, and 10−4/s. Then, surface observation by Optical Microscope (OM), Scanning Electron Microscopy (SEM), and Electron Back-scattered Diffraction (EBSD) was applied to obtain the microstructure mechanism. With pole figure maps (PF) for α-phase, obvious...
Source
#1Qingqing Ding (ZJU: Zhejiang University)H-Index: 9
#2Hongbin Bei (ZJU: Zhejiang University)H-Index: 62
Last. Ze Zhang (ZJU: Zhejiang University)H-Index: 77
view all 5 authors...
Abstract The GH3536 (Hastelloy X) superalloy is one of the most widely used Ni-based sheet alloys for gas turbine hot parts. In order to investigate its relationship among the processing, microstructure, and mechanical properties, GH3536 alloy was fabricated from pure constituent elements by arc melting and drop casting. The drop-cast ingots were homogenized, cold rolled and recrystallized to obtain single phase microstructure with average grain size of ∼ 12 μm. Tensile tests were then performed...
3 CitationsSource
#1Ahmed O. MoslehH-Index: 9
#2Anton D. KotovH-Index: 13
view all 5 authors...
1 CitationsSource
#1Yanfei Gao (UT: University of Tennessee)H-Index: 38
#2Wei Zhang (UT: University of Tennessee)H-Index: 132
Last. Yifei Zhong (SHU: Shanghai University)H-Index: 16
view all 5 authors...
Abstract Among various mechanisms responsible for the strength-ductility trade-off in metallic materials, the leading strategy is to delay the onset of necking by improving the work hardening rate via a number of metallurgical approaches such as heterogeneous or gradient microstructures. Recent research activities on high-entropy alloys also witness a wide range of alloy design capabilities that permit these microstructural designs such as the dual-phase lamellar microstructures. This work addre...
1 CitationsSource