Fatigue strength and fracture behavior of steels with and without interstitial carbon at room temperature in air

2007 ◽  
Vol 98 (3) ◽  
pp. 209-216 ◽  
Author(s):  
Mohammed Aminul Islam ◽  
Yo Tomota
Keyword(s):  
Fatigue Strength ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Interstitial Carbon

Superplastic Bulging of Nanocrystalline Ni-Co Alloy with Different Heating Methods

2012 ◽  
Vol 735 ◽  
pp. 136-139
Author(s):  
Guo Feng Wang ◽  
Shao Song Jiang ◽  
Zhen Lu ◽  
Kai Feng Zhang
Keyword(s):  
Nanocrystalline Materials ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Hot Spot ◽  
Tensile Tests ◽  
Complex Stress ◽  
Resistance Heating ◽  
Furnace Temperature ◽  
Temperature Heating ◽  
Room Temperature Strength

Superplasticity of nanocrystalline materials is a hot spot in the field of scientific research. In this paper, Ni-Co alloy was produced through pulse electrodeposition. Tensile tests were carried out to study the room temperature strength, high temperature plasticity. The superplastic formability under complex stress was evaluated through the superplastic bulging tests. The tests were studied through the methods of resistance heating and furnace temperature heating. The maximum ratios of height and diameter with different heating method were compared. Fracture behavior and microstructure were observed by the method of SEM.

Effects of Mg Content on the Fatigue Strength and Fracture Behavior of Al-Si-Mg Casting Alloys

2018 ◽  
Vol 27 (11) ◽  
pp. 5992-6003 ◽  
Author(s):  
Ming-Ze Wu ◽  
Ji-Wang Zhang ◽  
Yan-Bin Zhang ◽  
Hua-Qiang Wang
Keyword(s):  
Fatigue Strength ◽  
Fracture Behavior ◽  
Casting Alloys ◽  
Mg Content

Anomalous Tensile Strength and Fracture Behavior of Polycrystalline Iridium from Room Temperature to 1600 °C

2018 ◽  
Vol 20 (7) ◽  
pp. 1701114 ◽  
Author(s):  
Jieren Yang ◽  
Hu Wang ◽  
Rui Hu ◽  
Shuangming Li ◽  
Yi Liu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fracture Behavior ◽  
Room Temperature

Ductility and Fracture Behavior of Single Crystalline Ni3Al with Boron Additions

1988 ◽  
Vol 133 ◽  
Author(s):  
F. E. Heredia ◽  
D. P. Pope
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strengthening Effect ◽  
Single Crystalline ◽  
B Additions ◽  
High Temperature Tensile ◽  
Tension Compression Asymmetry ◽  
Positive Effect

ABSTRACTLow and high temperature tensile tests were performed on single crystals of pure Ni3Al and Ni3Al+B in order to determine the effect of B additions on the ductility and fracture behavior. Tests were carried out in air at a constant strain rate of 1.3 × 10−3 s−1. The orientations tested were [001] for which the yield stress in tension is always greater than in compression, and those for which the tension/compression asymmetry is zero ([T=C]) for each particular composition. At room temperature, the results show a positive effect of B additions on both the fracture stress and on the ductility. The ductility at 800K appears to decrease monotonically with B additions. The largest ductilities are found for [T=C] at room temperature where an improvement of about 26% (resolved strain) for an addition of 0.2 at% B was obtained. However, the most dramatic increase in ductility occurs for the [001] oriented samples at room temperature where a 55% improvement was measured over that of pure Ni3Al. Fracture surfaces show a combination of massive slip, some cleavage, and heavily dimpled areas. These observations show that B additions not only increase the ductility of polycrystalline Ni3Al, as has been previously observed by many investigators, but also that of the already-ductile single crystalline material, indicating that a “bulk effect” should be added to the grain boundary strengthening effect of B when explaining the improvement in ductility of polycrystalline Ni3Al due to B additions.

Ductility and Fracture Behavior of Polycrystalline Ni3Al Alloys

1986 ◽  
Vol 81 ◽  
Author(s):  
C. T. Liu
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Grain Shape ◽  
Tensile Ductility ◽  
Dynamic Effect ◽  
Al Alloys ◽  
Gaseous Oxygen ◽  
Comprehensive Review ◽  
Room Temperature Ductility

AbstractThis paper provides a comprehensive review of the recent work on tensile ductility and fracture behavior of Ni3AI alloys tested at ambient and elevated temperatures. Polycrystalline Ni3Al is intrinsically brittle along grain boundaries, and the brittleness has been attributed to the large difference in valency, electronegativity, and atom size between nickel and aluminum atoms. Alloying with B, Mn, Fe, and Be significantly increases the ductility and reduces the propensity for intergranular fracture in Ni3 Al alloys. Boron is found to be most effective in improving room-temperature ductility of Ni3Al with <24.5 at. % Al.The tensile ductility of Ni3Al alloys depends strongly on test environments at elevated temperatures, with much lower ductilities observed in air than in vacuum. The loss in ductility is accompanied by a change in fracture mode from transgranular to intergranular. This embrittlement is due to a dynamic effect involving simultaneously high localized stress, elevated temperature, and gaseous oxygen. The embrittlement can be alleviated by control of grain shape or alloying with chromium additions. All the results are discussed in terms of localized stress concentration and grain-boundary cohesive strength.

scholarly journals Application of a √ area -Approach for Fatigue Assessment of Cast Aluminum Alloys at Elevated Temperature

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1033 ◽  
Author(s):  
Roman Aigner ◽  
Christian Garb ◽  
Martin Leitner ◽  
Michael Stoschka ◽  
Florian Grün
Keyword(s):  
Elevated Temperature ◽  
Fatigue Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Damage Mechanism ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Cast Aluminum ◽  
Fatigue Assessment ◽  
Cast Aluminum Alloys

This paper contributes to the effect of elevated temperature on the fatigue strength of common aluminum cast alloys EN AC-46200 and EN AC-45500. The examination covers both static as well as cyclic fatigue investigations to study the damage mechanism of the as-cast and post-heat-treated alloys. The investigated fracture surfaces suggest a change in crack origin at elevated temperature of 150 ∘ C. At room temperature, most fatigue tests reveal shrinkage-based micro pores as their crack initiation, whereas large slipping areas occur at elevated temperature. Finally, a modified a r e a -based fatigue strength model for elevated temperatures is proposed. The original a r e a model was developed by Murakami and uses the square root of the projected area of fatigue fracture-initiating defects to correlate with the fatigue strength at room temperature. The adopted concept reveals a proper fit for the fatigue assessment of cast Al-Si materials at elevated temperatures; in detail, the slope of the original model according to Murakami should be decreased at higher temperatures as the spatial extent of casting imperfections becomes less dominant at elevated temperatures. This goes along with the increased long crack threshold at higher operating temperature conditions.

scholarly journals Modeling anisotropic ductile fracture behavior of Ti-6Al-4V titanium alloy for sheet forming applications at room temperature

2020 ◽  
Vol 207 ◽  
pp. 178-195
Author(s):  
Bingtao Tang ◽  
Qingfeng Wang ◽  
Ning Guo ◽  
Xinsheng Li ◽  
Qiaoling Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Ductile Fracture ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Sheet Forming

scholarly journals The Evolution of Interfacial Microstructure and Fracture Behavior of Short Carbon Fiber Reinforced 2024 Al Composites at High Temperature

2019 ◽  
Vol 9 (17) ◽  
pp. 3477
Author(s):  
Chi Zhang ◽  
Jinhao Wu ◽  
Qingnan Meng ◽  
Youhong Sun ◽  
Mao Wen
Keyword(s):  
Carbon Fiber ◽  
Fracture Surface ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Aluminum Matrix ◽  
Interfacial Microstructure ◽  
Fiber Content ◽  
Fiber Reinforced ◽  
Short Carbon Fiber ◽  
Short Carbon

The short carbon fiber reinforced 2024 Al composites were fabricated through powder metallurgy. The effect of short carbon fiber content on the interfacial microstructure and fracture behavior of the composites at different temperatures were investigated. The results showed that the dislocation accumulation was formed in the aluminum matrix due to the thermal expansion mismatch between carbon fiber and aluminum matrix. With the testing temperature increasing, the size of interfacial product Al4C3 and precipitates Al2Cu became larger, and the segregation of Al2Cu was found coarsening around Al4C3. The addition of short carbon fiber improved the hardness and modulus of the aluminum matrix in the vicinity of the interface between carbon fiber and aluminum matrix. Compared to the matrix 2024 Al, the yield strength and ultimate tensile strength of the composites first increased and then decreased with increasing short carbon fiber content at room temperature 423 Kand 523 K. The fracture surface of the composites at room temperature was characterized by shear failure of fiber, while the interface debonding and fiber pulled-out became predominant fracture morphologies for the fracture surface at increased temperatures.

Effects of Aged Conditions on the Fracture Surface Fractal Dimension and Mechanical Behavior of an Austenitic Stainless Steel

2000 ◽  
Vol 6 (S2) ◽  
pp. 768-769
Author(s):  
O. A. Hilders ◽  
A. Quintero ◽  
L. Berrio ◽  
R. Caballero ◽  
L. Sáenz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Fractal Dimension ◽  
Fractal Geometry ◽  
Fracture Behavior ◽  
Main Part ◽  
Room Temperature ◽  
Fracture Topography ◽  
Type Stainless Steel ◽  
Strength And Ductility

There have been several attempts to find a relation between the fractal morphology of the fracture surfaces and the mechanical properties of engineering materials., although the current resuls are inconclusive. If there are correlations between the fractal dimension and such properties, this parameter could be very useful to predict them and to improve the resistance to fracture. The main part of the investigations concerned with the fractal geometry and fracture behavior concentrate on the relations between roughness and fracture toughness . In the present work, the effects of thermal aging at 850°C on the fracture topography developed during the rupture in tension at room temperature of a 304 type stainless steel and their relation with the strength and ductility, were studied using the fractal geometry approach.

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