Influence of Dislocation Mobility on Room and High Temperature Ductility of -Oriented Nial Single Crystals

1994 ◽  
Vol 364 ◽  
Author(s):  
M. A. Morris ◽  
J. P. Perez ◽  
R. Darolia
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
Room Temperature ◽  
Tensile Tests ◽  
Slip Systems ◽  
Dislocation Mobility ◽  
Screw Dislocations ◽  
Large Density ◽  
Thin Foils

AbstractThe dislocation configurations produced by room and high temperature compression of <100> oriented single crystals of binary NiAl and in those containing iron and hafnium additions have been analysed and compared to those obtained by hardness indentation and TEM insitu tensile tests. Kinking occurs during room temperature compression such that <100> dislocations are activated in all cases but the iron-containing alloy also exhibited a large density of <111> screw dislocations. The latter however, appear immobile when they are created by hardness indentations of thin foils, while only pile-ups of <100> segments can propagate. Similarly, although different slip systems are present after high temperature compression, only <100> dislocation segments have been confirmed to be mobile after room temperature hardness indentation of these predeformed thin foils. The improvement in ductility observed at room temperature in the predeformed specimens of the binary and the iron containing alloys has been attributed to the increased production of these mobile <100> dislocations.

scholarly journals Room-temperature deformation of single crystals of ZrB2 and TiB2 with the hexagonal AlB2 structure investigated by micropillar compression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenghao Chen ◽  
Bhaskar Paul ◽  
Sanjib Majumdar ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
...  
Keyword(s):  
Single Crystals ◽  
Plastic Flow ◽  
Room Temperature ◽  
Resolve Shear Stress ◽  
Temperature Deformation ◽  
Slip Systems ◽  
Compression Tests ◽  
Plastic Deformation Behavior ◽  
Bulk Single Crystals ◽  
Micropillar Compression

AbstractThe plastic deformation behavior of single crystals of two transition-metal diborides, ZrB2 and TiB2 with the AlB2 structure has been investigated at room temperature as a function of crystal orientation and specimen size by micropillar compression tests. Although plastic flow is not observed at all for their bulk single crystals at room temperature, plastic flow is successfully observed at room temperature by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> in ZrB2 and by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> in TiB2. Critical resolve shear stress values at room temperature are very high, exceeding 1 GPa for all observed slip systems; 3.01 GPa for {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> slip in ZrB2 and 1.72 GPa and 5.17 GPa, respectively for {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> slip in TiB2. The identified operative slip systems and their CRSS values are discussed in comparison with those identified in the corresponding bulk single crystals at high temperatures and those inferred from micro-hardness anisotropy in the early studies.

Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi
Keyword(s):  
Single Crystals ◽  
Deformation Behavior ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Temperature Range ◽  
Al Content ◽  
Partial Dislocations ◽  
Increasing Temperature ◽  
Critical Resolved Shear Stress

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

Manufacturing and High Temperature Mechanical Properties of Inconel 713C by Using Metal Injection Molding

2012 ◽  
Vol 602-604 ◽  
pp. 627-630 ◽  
Author(s):  
Kyu Sik Kim ◽  
Kee Ahn Lee ◽  
Jong Ha Kim ◽  
Si Woo Park ◽  
Kyu Sang Cho
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Injection Molding ◽  
Room Temperature ◽  
Tensile Tests ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Molding Process ◽  
High Temperature Mechanical Properties ◽  
Inconel 713C

Inconel 713C alloy was tried to manufacture by using MIM(Metal Injection Molding) process. The high-temperature mechanical properties of MIMed Inconel 713C were also investigated. Processing defects such as pores and binders could be observed near the surface. Tensile tests were conducted from room temperature to 900°C. The result of tensile tests showed that this alloy had similar or somewhat higher strengths (YS: 734 MPa, UTS: 968 MPa, elongation: 7.16 % at room temperature) from RT to 700°C than those of conventional Inconel 713C alloys. Above 800°C, however, ultimate tensile strength decreased rapidly with increasing temperature (lower than casted Inconel 713C). Based on the observation of fractography, initial crack was found to have started near the surface defects and propagated rapidly. The superior mechanical properties of MIMed Inconel 713C could be obtained by optimizing the MIM process parameters.

Effect of High Temperature Caliber Rolling on Microstructure and Room Temperature Tensile Properties of Mg-3Al-1Zn (AZ31) Alloy

2013 ◽  
Vol 209 ◽  
pp. 6-9 ◽  
Author(s):  
Rajendra Doiphode ◽  
S.V.S. Narayana Murty ◽  
Nityanand Prabhu ◽  
Bhagwati Prasad Kashyap
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Yield Strength ◽  
Strain Rate ◽  
Tensile Properties ◽  
Room Temperature ◽  
Tensile Tests ◽  
Az31 Alloy ◽  
Rolling Temperature ◽  
Grain Sizes

Mg-3Al-1Zn (AZ31) alloy was caliber rolled at 250, 300, 350, 400 and 450 °C. The effects of caliber rolling temperature on the microstructure and tensile properties were investigated. The room temperature tensile tests were carried out to failure at a strain rate of 1 x 10-4s-1. The nature of stress-strain curves obtained was found to vary with the temperature employed in caliber rolling. The yield strength and tensile strength followed a sinusoidal behaviour with increasing caliber rolling temperature but no such trend was noted in ductility. These variations in tensile properties were explained by the varying grain sizes obtained as a function of caliber rolling temperature.

Characterization of the High Temperature Dislocation Substructure of Mosi2

1994 ◽  
Vol 364 ◽  
Author(s):  
J. P. Campbell ◽  
H. Chang ◽  
R. Gibala
Keyword(s):  
High Temperature ◽  
Deformation Behavior ◽  
Dislocation Substructure ◽  
Dislocation Climb ◽  
Slip Systems ◽  
Quantitative Characterization ◽  
Temperature Variations ◽  
Screw Dislocations ◽  
Orientation Distributions

AbstractThe dislocation substructure of polycrystalline MoSi2 deformed in compression at temperatures ranging from 900°C to 1300°C has been investigated. Slip is found to occur primarily by <100> Burgers vectors. A quantitative characterization of the <100> dislocation substructure is developed for several deformation temperatures, including the slip systems present and the relative occurrence of each. Orientation distributions showing the screw/edge character of the <100> dislocations are generated at each deformation temperature. Variations in these distributions with temperature are noted, and the implications of these variations to the deformation behavior of MoSi2 are discussed. Notable observations include the onset of dislocation climb between 900°C and 1100°C, a strong preference for dislocations of mixed character at 900°C, and the complete absence of pure screw dislocations from 900°C to 1300°C.

Deformation Behavior of Polycrystalline AZ31 Alloy at Room and Elevated Temperatures

2005 ◽  
Vol 488-489 ◽  
pp. 775-778
Author(s):  
Tsing Zhou ◽  
Goroh Itoh ◽  
Yohei Iseno ◽  
Yoshinobu Motohashi
Keyword(s):  
Deformation Behavior ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Az31 Alloy ◽  
Slip Systems ◽  
Type Specimens ◽  
Rolled Specimen ◽  
Hot Rolled

The hot-rolled and extruded AZ31 specimens are subjected to tensile tests at room and elevated temperatures. At room temperature, the yield stress of the hot-rolled specimen is significantly higher than that of the extruded, the reason for which is related to the different textures developed in the two type specimens, as well as the different slip systems activated. At elevated temperatures, the strain rate sensitivity and the activation energy are obtained to characterize the deformation mechanism of the alloy during the temperature range of 423~573K.

High Temperature Deformation of Single Crystalline Cr3Si (A15) Intermetallic Compound

1990 ◽  
Vol 213 ◽  
Author(s):  
C. Steve Chang ◽  
D. P. Pope
Keyword(s):  
High Temperature ◽  
Intermetallic Compound ◽  
Single Crystals ◽  
Intermetallic Compounds ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Slip Systems ◽  
Compression Tests ◽  
Single Crystalline ◽  
Slip Traces

AbstractHigh temperature compression tests were performed on Cr 3Si single crystalline and poly crystalline samples. Slip systems were determined to be of the {001}<010> type based on an analysis of slip traces and Laue spots. Single crystals show significant compressive ductility at temperatures above 0.7Tm. The implication of cube slip on the ductility of A15-type intermetallic compounds is discussed.

Plastic Deformation of Ti3Al and Ti3Al/TiA1 Polycrystals

1988 ◽  
Vol 133 ◽  
Author(s):  
S. A. Court ◽  
J. P. A. Löfvander ◽  
M. A. Stucke ◽  
P. Kurath ◽  
H. L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Covalent Bonding ◽  
Relative Activity ◽  
Slip Systems ◽  
Dislocation Mobility ◽  
Two Phase ◽  
Influence Of Temperature ◽  
Transmission Electron

ABSTRACTSamples of polycrystalline Ti3Al-base alloys, and a two phase Ti3Al/TiAl mixture have been deformed at room temperature and at elevated temperatures and examined subsequently by transmission electron microscopy in order to determine the influence of temperature and alloy content on the relative activity of the various slip systems. In particular, the detailed influence of covalent bonding on dislocation mobility in Ti3Al has been identified.

Activities of Non-Basal Slips in Rolled Mg-Li and Mg-Ce Alloys Sheets

2021 ◽  
Vol 1016 ◽  
pp. 917-921
Author(s):  
Haruka Miyano ◽  
Keisuke Takemoto ◽  
Hiromoto Kitahara ◽  
Shinji Ando
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Tensile Tests ◽  
Lithium Content ◽  
Slip Systems ◽  
Alloying Additions ◽  
Alloy Strength ◽  
Critical Resolved Shear Stress ◽  
The Relationship ◽  
Strength And Ductility

In this study, tensile tests of rolled Mg-Li alloy and Mg-Ce alloy sheets were carried out at room temperature to investigate effects of alloying additions on the relationship between mechanical properties and activities of slip systems in magnesium polycrystals. In Mg-Li alloy, ductility increased while strength decreased by lithium addition. Frequency of non-basal slips increased with increasing lithium content. In Mg-Ce alloy, strength and ductility were similar pure magnesium, and non-basal slips were hardly activated. Since critical resolved shear stress of non-basal slips were decreased by lithium addition, ductility of magnesium was increased while its strength was decreased.

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