Tensile and Creep Properties of the Refractory Nb Base In-Situ Composite

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1608-1614
Author(s):  
Jin Hak Kim ◽  
Tatsuo Tabaru ◽  
Hisatoshi Hirai
Keyword(s):  
Fracture Surface ◽  
Tensile Tests ◽  
Constant Load ◽  
Tensile Creep ◽  
Tensile Fracture ◽  
Creep Tests ◽  
Tensile Fracture Surface ◽  
In Situ Composite ◽  
Temperature Ranges

Niobium-base in-situ composite Nb-18Si-5Mo-5Hf-2C (in mol%) was prepared and heat-treated at 2070 K for 20 hour. The uni-axile tensile tests at high temperature ranges and the constant load tensile creep tests at 1570 K were performed. The specimen tensile-tested at 1470 K exhibited the excellent UTS of 450 MPa, and the brittle to ductile transition temperature is between 1470 and 1670 K. The specimens creep tested showed good creep strength; the stress exponent is about 5. The tensile fracture surface of the in-situ composite is complex and attributed to cleavage of the Nb 5 Si 3, Nb ss / Nb 5 Si 3 interface separation, ductile rupture of the Nb ss and correlations of these. On the otherhand, the fracture surface of creep tested consists of intergranular above 150 MPa and transgranular below 120 MPa with severely deformed Nb ss .

The Fracture Morphology of Composites with Quasicrystalline Phase

2013 ◽  
Vol 203-204 ◽  
pp. 376-379
Author(s):  
Włodzimierz Bogdanowicz ◽  
Jacek Krawczyk
Keyword(s):  
Fracture Surface ◽  
Tensile Test ◽  
Fracture Morphology ◽  
Bridgman Method ◽  
Tensile Fracture ◽  
Quasicrystalline Phase ◽  
Tensile Fracture Surface ◽  
Fe Alloys

The composites of Al-Cu-Fe alloys with fibrous reinforcement, containing quasicrystals, e.i. crystal-quasicrystal composites (CQ composites) were studied. The composites were obtained in situ by the Bridgman method. The plate-like samples were studied by tensile test performed up to rupture. Tensile fracture surface of composite and reinforcement fibers were investigated. The role of voids on the fracture morphology and the reason of its formation were discussed.

Scanning Electron Microscopy Studies of Nitrile Rubber Fractured Surfaces

1980 ◽  
Vol 53 (2) ◽  
pp. 321-326 ◽  
Author(s):  
A. K. Bhowmick ◽  
S. Basu ◽  
S. K. De
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fracture Surface ◽  
Polymer Fibers ◽  
Tensile Fracture ◽  
Flow Lines ◽  
Tensile Fracture Surface ◽  
Test Conditions ◽  
Heat Buildup ◽  
Scanning Electron

Abstract The fracture surfaces of a NBR vulcanizate after different test conditions have been studied by scanning electron microscopy. It has been shown that failure surfaces manifest typical characteristics dependent on the nature of the test. Tensile fracture surface shows occurrence of two different tear rates in the case of a filled NBR vulcanizate, while tear fracture is characterized by a few long flow lines. De Mattia flexing leads to layering of polymer fibers. Heat buildup and abrasion tests generate a ribbed structure on the surface.

Evaluation of Mechanical Properties and Microstructures of Casing-Drilling Steels

2010 ◽  
Vol 146-147 ◽  
pp. 674-677
Author(s):  
Tian Han Xu ◽  
Yao Rong Feng ◽  
Sheng Yin Song ◽  
Zhi Hao Jin
Keyword(s):  
Mechanical Properties ◽  
Fracture Surface ◽  
Impact Energy ◽  
Cleavage Fracture ◽  
Fracture Mechanism ◽  
Tensile Fracture ◽  
Tensile Fracture Surface ◽  
Dimple Fracture ◽  
Drilling Technology ◽  
Casing Drilling

An investigation into the mechanical properties of K55，N80 and P110 steels was carried out for casing-drilling technology. The obvious presence of bright facets on broken K55 Charpy V-Notch (CVN) sample surfaces was indicative of the effect of microstructure on the cleavage fracture. The appearing of bright facet surfaces of K55 was attributed to the microstructure of ferrite and pearlite. The fracture surfaces of N80 and P110 CVN samples included quasi-cleavage fracture mechanism and dimple fracture mechanism, respectively. The tensile fracture surface of all three types of casing-drilling steels included dimple fracture mechanism, both the N80 and P110 specimen show higher UTS and impact energy values compared to the K55 specimen.

Mechanical Properties and Fracture Study of Alumina Dispersion Hardened Copper-Based Nano-Composite at Elevated Temperatures

2013 ◽  
Vol 829 ◽  
pp. 583-588 ◽  
Author(s):  
Ali Dalirbod ◽  
Yahya A. Sorkhe ◽  
Hossein Aghajani
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fracture Surface ◽  
Yield Strength ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Testing Temperature ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Different Temperatures

Alumina dispersion hardened copper-base composite was fabricated by internal oxidation method. The high temperature tensile fracture of Cu-Al2O3 composite was studied and tensile strengths were determined at different temperatures of 600, 680 and 780 °C. Microstructure was investigated by means of optical microscope and field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS). Results show that, ultimate tensile strength and yield strength of copper alumina nanocomposite decrease slowly with increasing temperature. The yield strength reaches 119 MPa and ultimate tensile strength reaches 132 MPa at 780 °C. Surface fractography shows a dimple-type fracture on the fracture surface of the tensile tests where dimple size increases with increasing testing temperature and in some regions brittle fracture characteristics could be observed in the fracture surface.

Effect of Long-Term Aging and Creep Exposure on the Microstructure of TiAl-Based Alloy for Industrial Applications

2004 ◽  
Vol 842 ◽  
Author(s):  
Juraj Lapin ◽  
Mohamed Nazmy ◽  
Marc Staubli
Keyword(s):  
Chemical Composition ◽  
Constant Load ◽  
Industrial Applications ◽  
Tensile Creep ◽  
Creep Tests ◽  
Fine Needle ◽  
Term Creep ◽  
Applied Stresses ◽  
Creep Exposure

ABSTRACTThe effect of long-term aging and creep exposure on the microstructure of a cast TiAl-based alloy with nominal chemical composition Ti-46Al-2W-0.5Si (at.%) was studied. The aging experiments were performed at temperatures between 973 and 1073 K for various times ranging from 10 to 14000 h in air. Constant load tensile creep tests were performed at applied stresses ranging from 150 to 400 MPa and at temperatures between 973 and 1123 K up to 25677 h. During aging and creep testing the α2(Ti3Al)-phase in the lamellar and feathery regions transforms to the γ(TiAl)-phase and fine needle-like B2 precipitates. Microstructural instabilities lead to a softening of the alloy. The effect of this softening on long-term creep resistance is negligible at temperatures of 973 and 1023 K.

Functionally Graded Ti-Ni Shape Memory Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 3169-3172 ◽  
Author(s):  
Tae Hyun Nam ◽  
Cheol Am Yu ◽  
Yun Jung Lee ◽  
Yinong Liu
Keyword(s):  
Temperature Gradient ◽  
Shape Memory ◽  
Tensile Tests ◽  
Constant Load ◽  
Functionally Graded ◽  
Scanning Calorimetry ◽  
Treated Sample ◽  
Ni Alloy ◽  
Temperature Ranges ◽  
Cold Worked

Shape memory characteristics and superelasticity of an temperature gradient annealing(TGA) treated equiatomic Ti-Ni alloy have been investigated by means of differential scanning calorimetry(DSC), thermal cycling tests under constant load and tensile tests. By annealing 25% cold worked alloy under the temperature gradient from 658 K to 466 K, 7 K variation in TR*and 19 K variation in Ms* were obtained along the length of sample(150mm). Temperature dependence of transformation elongation(dε/dT) of TGA treated Ti-Ni alloy wires was in the range of 0.05 %/K and 0.01 %/K depending on annealing temperature ranges. The dε/dT obtained from TGA treated sample under the temperature gradient from 658 K to 466 K was 0.03 %/K. TGA treated alloy showed the clear superelastic recovery.

SANS Investigation of γ´ Precipitate Morphology Evolution in Creep Exposed Single Crystal Ni Base Superalloy

2010 ◽  
Vol 636-637 ◽  
pp. 1475-1482
Author(s):  
Jozef Zrník ◽  
Pavel Strunz ◽  
Maurizio Maldini ◽  
Vadim Davydov
Keyword(s):  
Single Crystal ◽  
Constant Load ◽  
Scattering Method ◽  
Creep Tests ◽  
Precipitate Morphology ◽  
Gamma Prime ◽  
Directional Coarsening ◽  
Structure Degradation ◽  
Temperature Ranges ◽  
Nickel Base

The creep degraded nickel base single crystal superalloy CMSX-4 of two axial orientations [001] and [111] was investigated with aim to assess the structure degradation. Constant load creep tests were conducted in the stress/temperature ranges of 250–780 MPa/750 – 50°C resulting in rupture time variation from 50 to 4000 hours. A combination of scanning electron microscopy (SEM) and non-destructive small-angle neutron scattering method (SANS) was used to investigate the directional coarsening (rafting) of the gamma prime (γ') precipitates in relation to the stress and temperature applied as well as to the initial crystallographic orientation of the specimens. The SANS results are discussed in terms of the correlation with the raft development, the axial orientation of specimen, the creep parameters and the mechanical properties.

Time Dependent Deformation During Indentation Testing

1996 ◽  
Vol 436 ◽  
Author(s):  
B. N. Lucas ◽  
W. C. Oliver ◽  
G. M. Pharr ◽  
J-L. Loubet
Keyword(s):  
Loading Rate ◽  
Time History ◽  
Tensile Tests ◽  
Constant Load ◽  
Indentation Creep ◽  
Creep Tests ◽  
Constant Rate ◽  
Indentation Tests ◽  
Constant Loading Rate ◽  
Indentation Strain

AbstractConstant loading rate/load indentation tests (1/P dP/dt) and constant rate of loading followed by constant load (CRL/Hold) indentation creep tests have been conducted on high purity electropolished indium. It is shown that for a material with a constant hardness as a function of depth, a constant (1/P dP/dt) load-time history results in a constant indentation strain rate (1/h dh/dt). The results of the two types of tests are discussed and compared to data in the literature for constant stress tensile tests. The results from the constant (1/P dP/dt) experiments appear to give the best correlation to steady-state uniaxial data.

Study of Wettability of Vinyl Resin on Carbon Fiber

2012 ◽  
Vol 217-219 ◽  
pp. 157-160
Author(s):  
Hong Qiang Sun ◽  
Xiao Qing Wu
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Fracture Surface ◽  
Epoxy Resin ◽  
Tensile Modulus ◽  
Epoxy Composites ◽  
Tensile Fracture ◽  
Interface Adhesion ◽  
Tensile Fracture Surface ◽  
Tensile Performance

The tensile performance of the vinyl resin casting body, epoxy resin casting body, carbon fiber(CF) reinforced vinyl composites and CF/epoxy composites has been presented. The morphology of tensile fracture surface of CF/epoxy and CF/vinyl has been compared, and the interface adhesion has been analysed. The results show the tensile strength for vinyl resin casting body is lower than epoxy resin casting body’s, the tensile modulus of them are close. But the tensile strength and modulus of CF/vinyl composites are both close to CF/epoxy composites. And the vinyl has the better interface adhesion and wettability on CF than epoxy.

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