scholarly journals Loading rate and temperature effects on the fracture toughness of a high strength bearing steel

2021 ◽  
Vol 245 ◽  
pp. 107600
Author(s):  
B. Alfredsson ◽  
S. Hazar ◽  
J. Lai
2018 ◽  
Vol 13 ◽  
pp. 877-885 ◽  
Author(s):  
A.A. Alabi ◽  
P.L. Moore ◽  
L.C. Wrobel ◽  
J.C. Campbell ◽  
W. He

2008 ◽  
Vol 33-37 ◽  
pp. 351-356 ◽  
Author(s):  
Ze Jian Xu ◽  
Yu Long Li ◽  
Masanori Kikuchi

The Mode I and Mode II dynamic fracture toughness (DFT) values, KId and KIId for high strength steels 40Cr and 30CrMnSiNi2A were evaluated using a combined experimental-numerical method. The tests were performed on three point bend (3PB) and shear specimens with Hopkinson pressure bar. The time of crack initiation was determined by a strain gauge. With the assistance of 3-D transient finite element analysis, the temporal evolution of the dynamic stress intensity factor under different loading rates was obtained, and the DFT was determined by the fracture initiation time. In Mode I tests, a brittle transgranular fracture was found in 40Cr, while evidence for ductile fracture was observed on the failure surface of 30CrMnSiNi2A. In Mode II tests, both tensile cracks and adiabatic shear bands were found for the two steels. The effect of ligament size on fracture toughness was discussed. The correlations of KId and KIId with loading rate were also investigated. The micromechanisms of loading rate effect on the DFT were discussed for both modes.


Author(s):  
D.M. Vanderwalker

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.


Author(s):  
J. Tong ◽  
L. Eyring

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.


2018 ◽  
Vol 60 (11) ◽  
pp. 1077-1083 ◽  
Author(s):  
Zhaoming Zhou ◽  
Xishui Guo ◽  
Tiejun Lin ◽  
Desen Mao

Alloy Digest ◽  
1994 ◽  
Vol 43 (11) ◽  

Abstract CARLSON ALLOYS C600 AND C600 ESR have excellent mechanical properties from sub-zero to elevated temperatures with excellent resistance to oxidation at high temperatures. It is a solid-solution alloy that can be hardened only by cold working. High strength at temperature is combined with good workability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Ni-470. Producer or source: G.O. Carlson Inc.


Alloy Digest ◽  
1994 ◽  
Vol 43 (1) ◽  

Abstract INCONEL ALLOY 725 is an age-hardenable alloy that displays high strength along with excellent ductility and toughness. Its corrosion resistance is comparable to alloy 625. Good flattening properties are exhibited in age-hardened tubing. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating and machining. Filing Code: Ni-445. Producer or source: Inco Alloys International Inc.


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