Physical and Mechanical Properties of Single Crystals of Co-Al-W Based Alloys with L12 Single-Phase and L12/fcc Two-Phase Microstructures

2010 ◽  
Vol 638-642 ◽  
pp. 1342-1347 ◽  
Author(s):  
Haruyuki Inui ◽  
Takashi Oohashi ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Yield Stress ◽  
Liquid Helium ◽  
Elastic Constants ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Helium Temperature ◽  
Two Phase

The values of all the three independent single-crystal elastic constants and polycrystalline elastic constants of Co3(Al,W) experimentally determined by resonance ultrasound spectroscopy at liquid helium temperature are 15~25% larger than those of Ni3(Al,Ta) but are considerably smaller than those previously calculated. Because of the large value of E111/E100 and cij of Co3(Al,W), two-phase microstructures with cuboidal L12 precipitates well aligned parallel to <100> and well faceted parallel to {100} are expected to form very easily in Co-base alloys, as confirmed indeed by experiment. Values of yield stress obtained for [001]-oriented L12/fcc two-phase single crystals moderately decrease with the increase in temperature up to 800°C and then decrease rapidly with temperature above 800°C without any anomaly in yield stress.

Physical and Mechanical Properties of Single Crystals of Co-Al-W Based Alloys with L12 Single-Phase and L12/fcc Two-Phase Microstructures

2008 ◽  
Vol 1128 ◽  
Author(s):  
Haruyuki Inui ◽  
Katsushi Tanaka ◽  
Kyosuke Kishida ◽  
Norihiko L. Okamoto ◽  
Takashi Oohashi
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Yield Stress ◽  
Liquid Helium ◽  
Elastic Constants ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Helium Temperature ◽  
Two Phase

AbstractSingle-crystal elastic constants of Co3(Al,W) with the cubic L12 structure have been experimentally measured by resonance ultrasound spectroscopy at liquid helium temperature. The values of all the three independent single-crystal elastic constants and polycrystalline elastic constants of Co3(Al,W) experimentally determined are 15~25% larger than those of Ni3(Al,Ta) but are considerably smaller than those previously reported. Two-phase microstructures with cuboidal L12 precipitates being well aligned parallel to <100> and well faceted parallel to {100} are expected to form very easily in Co-base superalloys because of the large value of E111/E100 and cij of Co3(Al,W). This is indeed confirmed by experiment. Values of yield stress obtained for both [001] and [¯123] orientations of L12/fcc two-phase single crystals moderately decrease with the increase in temperature up to 800°C and then decrease rapidly with temperature above 800°C without any anomaly in yield stress. Slip on {111} is observed to occur for both orientations in the whole temperature range investigated.

Physical and Mechanical Properties of Co3(Al,W) with the L12 Structure in Single and Polycrystalline Forms

2011 ◽  
Vol 465 ◽  
pp. 9-14 ◽  
Author(s):  
Haruyuki Inui ◽  
Takashi Oohashi ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka
Keyword(s):  
Mechanical Properties ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Single Crystal ◽  
Elastic Constants ◽  
Tensile Elongation ◽  
Physical And Mechanical Properties ◽  
Helium Temperature ◽  
Cauchy Pressure ◽  
L12 Structure

The physical and mechanical properties of Co3(Al,W) with the L12 structure have been investigated both in single and polycrystalline forms. The values of all the three independent single-crystal elastic constants and polycrystalline elastic constants of Co3(Al,W) experimentally determined by resonance ultrasound spectroscopy at liquid helium temperature are 15~25% larger than those of Ni3(Al,Ta) but are considerably smaller than those previously calculated. When judged from the values of Poisson’s ratio, Cauchy pressure and Gh (shear modulus)/Bh (bulk modulus), the ductility of Co3(Al,W) is expected to be sufficiently high. Indeed, the value of tensile elongation obtained in air is as large as 28 %, which is far larger than that obtained in Ni3Al polycrystals under similar conditions.

High Cycle Fatigue Behaviour of Cu/Sn Intermetallic Compounds Prepared by Transient Liquid Phase Bonding Process

2021 ◽  
Vol 1016 ◽  
pp. 268-273
Author(s):  
Agnieszka Betzwar Kotas ◽  
Golta Khatibi ◽  
Farzad Khodabakhshi ◽  
Andreas Steiger-Thrisfeld
Keyword(s):  
Mechanical Properties ◽  
Liquid Phase ◽  
Single Phase ◽  
Transient Liquid Phase ◽  
Physical And Mechanical Properties ◽  
Test System ◽  
Bending Test ◽  
Fatigue Properties ◽  
Phase System ◽  
Two Phase

Transient liquid phase (TLP) bonds using Cu-Sn system have been suggested as high strength and temperature resistant joints for power electronics applications. While the physical and mechanical properties of these joints has been investigated to some extent, studies on fatigue properties and long term reliability of TLP joints are scarce. In this work TLP bonding was performed to produce thin Cu-Sn intermetallic joints by using Cu and 97Sn3Cu solder alloy as interlayer. Different processing conditions resulted in three types of thin joints consisting of three phases (Cu3Sn/Cu6Sn5/solder remnants), two phases (Cu3Sn/Cu6Sn5) and a single phase (Cu3Sn) with an overall thickness of ≤ 20 μm. The shear strength of the TLP joint containing one or two high melting point IMC layers showed a significant temperature resistance up to 200°C. Fatigue studies of TLP joints were conducted by using a 3-point-cyclic bending test system operating at 20 kHz. The highest fatigue resistance was obtained for the single-phase Cu3Sn joints with superior shear and flexural resistance. The two phase joints (Cu3Sn/Cu6Sn5) showed a slightly lower lifetime than the three phase system containing IMCs and residual solder. Fracture surfaces analysis in correlation with static and cyclic mechanical properties, provided insight into the failure mechanism of the Cu-Sn TLP joints.

Mechanical Properties of Cr5Si3 with the D8m Structure

2011 ◽  
Vol 1295 ◽  
Author(s):  
Yuji Ochiai ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka ◽  
Haruyuki Inui
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Plastic Deformation ◽  
Thermal Expansion ◽  
Bulk Modulus ◽  
Single Crystal ◽  
Single Crystals ◽  
Elastic Constants ◽  
Deformation Behavior ◽  
Loading Axis

ABSTRACTElastic properties, thermal expansion and deformation behavior of Cr5Si3 with the D8m structure were investigated using single crystals. From the values of Cauchy pressures as well as the ratio of the polycrystalline bulk modulus (B) to shear moduls (G) estimated from single-crystal elastic constants (cij), deformation behavior of Cr5Si3 is expected to be relatively brittle compared to Mo5Si3 with the same crystal structure. However, plastic deformation of Cr5Si3 is confirmed above 900 ~ 1100 °C depending on the loading axis orientations.

DECcalc - A Program for the Calculation of Diffraction Elastic Constants from Single Crystal Coefficients

2011 ◽  
Vol 681 ◽  
pp. 417-419 ◽  
Author(s):  
Thorsten Manns ◽  
Berthold Scholtes
Keyword(s):  
Computer Program ◽  
Single Crystal ◽  
Elastic Constants ◽  
Single Phase ◽  
Proper Function ◽  
Almost All

A Matlab based computer program was developed which gives the possibility to calculate the diffraction elastic constants (DEC) of macroscopically isotropic, single phase materials from their single crystal elastic constants. The proper function of the program was confirmed by means of results from literature. In almost all cases the results from the program DECcalc could reproduce the values and diagrams given in the appropriate publications. Discrepancies could always be assigned to the use of different single crystal coefficients.

The Fabricated Collagen-Based Nano-Hydroxyapatite/β-Tricalcium Phosphate Scaffolds

2012 ◽  
Vol 506 ◽  
pp. 57-60 ◽  
Author(s):  
M. Ebrahimi ◽  
Naruporn Monmaturapoj ◽  
S. Suttapreyasri ◽  
P. Pripatnanont
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Calcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Total Porosity ◽  
Xrd Pattern ◽  
Collagen Coating ◽  
Dimensional Shrinkage

The biphasic calcium phosphate (BCP) concept was introduced to overcome disadvantages of single phase biomaterials. In this study, we prepared BCP from nanoHA and β-TCP that were synthesized via a solid state reaction. Three different ratios of pure BCP and collagen-based BCP scaffolds (%HA/%β-TCP; 30/70, 40/60 and 50/50) were produced using a polymeric sponge method. Physical and mechanical properties of all materials and scaffolds were investigated. XRD pattern proved the purity of each HA, β-TCP and BCP. SEM showed overall distribution of macropores (80-200 µm) with appropriate interconnected porosities. Total porosity of pure BCP (93% ± 2) was found to be higher than collagen-based BCP (85%± 3). It was observed that dimensional shrinkage of larger scaffold (39% ± 4) is lower than smaller one (42% ± 5) and scaffolds with higher HA (50%) ratio experienced greater shrinkage than those with higher β-TCP (70%) ratio (45% ±3 and 36% ±1 respectively). Mechanical properties of both groups tend to be very low and collagen coating had no influence on mechanical behavior. Further studies may improve the physical properties of these composite BCP.

Magnesium-Silicon Substituted Carbonate Hydroxyapatite (Mg-Si CHA): Factors Affecting Sintering

2016 ◽  
Vol 694 ◽  
pp. 88-93
Author(s):  
Ahmad Fauzi Mohd Noor ◽  
Harmiza Zainudin
Keyword(s):  
Mechanical Properties ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Major Effect ◽  
Carbonate Content ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Complex Process ◽  
Powder Properties ◽  
Properties Of Materials

Sintering has major effect on the final properties of materials such as density, porosity and microstructure. Sintering of Mg-Si CHA in particular is a complex process since changes could occur during sintering, which include phase formation, grain size, pore size and carbonate content, and this in turn affects the mechanical properties. Improved mechanical properties of Mg-Si CHA is critical in load bearing implant applications. Poor control of thermal treatment of Mg-Si CHA during sintering would cause carbonate loss, leading to partial or total decomposition of Mg-Si CHA, subsequently would affect the physical and mechanical properties. The influence of powder properties (particle size, porosity, morphology) and sintering parameters (heating rate, firing atmosphere) on the sintered Mg-Si CHA microstructure was studied using scanning electron microscopy (SEM) characterization technique. The SEM results showed that we are able to produce sintered Mg-Si CHA without cracking of the compacted pellets, while keeping the carbonate level in the amount required (2 – 8%). X-Ray diffraction (XRD) was also performed on the sintered samples and the results indicated that a single phase Mg-Si-CHA was obtained, while Fourier transform infra-red (FTIR) spectroscopy result confirmed that as-synthesized Mg-Si CHA powder was a B-type.

The Effect of Solid Solution Impurities on Dislocation Nucleation in a (001) Mo – 1.5 at.% Ir Single Crystal

2010 ◽  
Vol 662 ◽  
pp. 85-93
Author(s):  
Sergey Dub ◽  
Igor Zasimchuk ◽  
Leonid Matvienko
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Shear Stress ◽  
Elastic Modulus ◽  
Single Crystal ◽  
Single Crystals ◽  
Free Volume ◽  
Dislocation Nucleation ◽  
Initial Portion ◽  
G 12

Mechanical properties of (001) Mo and (001) Mo – 1.5 at.% Ir single crystals have been studied by nanoindentation. It has been found that the iridium addition to molybdenum leads to an increase in both hardness and elastic modulus. An abrupt elasto-plastic transition (pop-in) at a depth of about 20 - 40 nm caused by dislocation nucleation in previously dislocation-free volume has been observed in the initial portion of the loading curve. It has shown that the Ir addition essentially affects the dislocation nucleation. Mean shear stress required for the dislocation nucleation increased from 10.8 GPa (G/12) for a Mo single crystal to 18.2 GPa (G/8) for the Mo – 1.5 at% Ir solid solution. Thus, the Ir solution in a Mo single crystal affects not only the resistance to the motion of dislocations (hardness) but the nucleation of them as well. The latter is likely to occur as a result of an increase in the structure perfection of the Mo – 1.5 at% Ir solid solution as compared to the pure Mo single crystal.

Micro pulling down growth of very thin shape memory alloys single crystals

2017 ◽  
Vol 10 (01) ◽  
pp. 1740003 ◽  
Author(s):  
I. López-Ferreño ◽  
J. San Juan ◽  
T. Breczewski ◽  
G. A. López ◽  
M. L. Nó
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloys ◽  
Single Crystal ◽  
Shape Memory ◽  
Single Crystals ◽  
Functional Materials ◽  
Small Scale ◽  
Cylindrical Shape ◽  
Minimum Diameter ◽  
Wide Range

Shape memory alloys (SMAs) have attracted much attention in the last decades due to their thermo-mechanical properties such as superelasticity and shape memory effect. Among the different families of SMAs, Cu–Al–Ni alloys exhibit these properties in a wide range of temperatures including the temperature range of 100–200[Formula: see text]C, where there is a technological demand of these functional materials, and exhibit excellent behavior at small scale making them more competitive for applications in Micro Electro-Mechanical Systems (MEMS). However, polycrystalline alloys of Cu-based SMAs are very brittle so that they show their best thermo-mechanical properties in single-crystal state. Nowadays, conventional Bridgman and Czochralski methods are being applied to elaborate single-crystal rods up to a minimum diameter of 1[Formula: see text]mm, but no works have been reported for smaller diameters. With the aim of synthesizing very thin single-crystals, the Micro-Pulling Down ([Formula: see text]-PD) technique has been applied, for which the capillarity and surface tension between crucible and the melt play a critical role. The [Formula: see text]-PD method has been successfully applied to elaborate several cylindrical shape thin single-crystals down to 200[Formula: see text][Formula: see text]m in diameter. Finally, the martensitic transformation, which is responsible for the shape memory properties of these alloys, has been characterized for different single-crystals. The experimental results evidence the good quality of the grown single-crystals.

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