The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Yong Xiang Zhao - One of the best experts on this subject based on the ideXlab platform.
-
Evolution of Effective Short Fatigue Cracks Density of LZ50 Axle Steel
Key Engineering Materials, 2011Co-Authors: Bing Yang, Yong Xiang ZhaoAbstract:Short fatigue crack density evolution on Specimen surface of railway LZ50 axle steel is studied experimentally by local and overall viewpoints, respectively. Results indicate that the density of effective short fatigue cracks (ESFCs) around dominant crack, which results in the Specimen Failure, evolutes sensitively to the changes of the dominant crack size and tip locations. In accordance with the previous criterion of ESFCs, this density evolution is more suitable for describing the intrinsic and dynamic localization and randomization of fatigue damage. At the same time, statistical deriving is applied to address the randomness of the evolution behavior. It is revealed that the density data increases with the dominant crack growth in the micro-structural short crack (MSC) regime, and keeps declining in the physical short crack (PSC) regime. Coefficient-of-variations exhibit a contrary tendency. Appropriate distribution is further determined using a previous comprehensive statistical comparison method. Random characters and quantitative measurements of the density data have been well depicted.
-
Surface Rolling Effect on Effective Short Fatigue Cracks Density for Railway LZ50 Axle Steel
Advanced Materials Research, 2010Co-Authors: Bing Yang, Yong Xiang ZhaoAbstract:Surface rolling effect on effective short fatigue cracks density, which reflect the affecting capacity on the initiation firstly and then growth of the dominant short crack result finally in Specimen Failure, is experimentally studied by a replica technique. Two groups of smooth hourglass shaped Specimens of LZ50 axle steel with/without rolled surfaces were tested. The crack density of surface rolled Specimens was much lower than that of the other group. This indicates surface rolling technology having the effect of hardening surface layer material to introduce compressive residual stresses. The effect appears to restrain the short crack nucleation and propagation and then, to extend the fatigue life.
H.-g. Sockel - One of the best experts on this subject based on the ideXlab platform.
-
Corrosion fatigue of cemented carbide cutting tool materials
Materials Science and Engineering: A, 2004Co-Authors: V.a. Pugsley, H.-g. SockelAbstract:The influence of a corrosive environment on the fatigue performance of two cemented carbides has been investigated. The corrosive media used were tannic acid and de-ionised water, chosen to simulate the environment encountered during wood cutting and metal cutting, respectively. The results show a corrosive environment to have a strong influence on the fatigue performance of the materials tested, such that Specimen Failure is observed at stress amplitudes equal to one quarter of the strength of the as-received material. The influence of the environment increases with decreasing stress amplitude and frequency. The mode of Failure observed under corrosion fatigue conditions requires the simultaneous action of corrosive attack and cyclic loading.
J G Huang - One of the best experts on this subject based on the ideXlab platform.
-
thermographic investigation of the fatigue behavior of reactor pressure vessel steels
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: B Yang, Hsin Wang, J.y. Huang, P K Liaw, L Jiang, J G HuangAbstract:The fatigue behavior of reactor pressure vessel (RPV) steels during fatigue testing was monitored by an advanced, high-speed, high-sensitivity, nondestructive evaluation (NDE) technique called infrared (IR) thermography. Five stages of temperature profiles during fatigue were recorded: an initial increase of the mean Specimen temperature followed by a temperature decrease, a constant (equilibrium) temperature region, an abrupt temperature increase, and a temperature drop after the Specimen Failure. Using the state-of-the-art IR camera, the temperature profiles were recorded cycle by cycle during 20 Hz fatigue testing. A theoretical model combining the thermoelastic, inelastic, and heat-conduction effects were used to explain and predict the temperature evolution during fatigue. Specifically, the temperature evolution was predicted, and the results were found to be in good agreement with the experimental data.
Kazuo Sato - One of the best experts on this subject based on the ideXlab platform.
-
Measurement for fracture toughness of single crystal silicon film with tensile test
Sensors and Actuators A: Physical, 2005Co-Authors: T. Kasai, Shigeki Nakao, Hiroshi Tanaka, Taeko Ando, Mitsuhiro Shikida, Kazuo SatoAbstract:Abstract We developed a method of measuring the fracture toughness, which is a material constant in the macroscopic domain, of micro-machined single crystal silicon film on the (1 0 0) plane. We notched the thin film Specimen on a single edge and then conducted a uniaxial tensile test to Specimen Failure. The average value of measured fracture toughness was 1.58 MPa m1/2, with scatter. This is slightly higher than, but comparable to, the value for bulk silicon. Scanning electron microscope (SEM) observation of the failed Specimens revealed that the fracture developed mainly along the (1 1 0) cleavage plane.
T Goshima - One of the best experts on this subject based on the ideXlab platform.
-
corrosion fatigue behavior of extruded magnesium alloy az31 in sodium chloride solution
International Journal of Fatigue, 2008Co-Authors: Sotomi Ishihara, T GoshimaAbstract:Abstract In the present study, corrosion fatigue experiments were done using the extruded magnesium alloy AZ31 in the 3% sodium chloride solution to clarify the corrosion fatigue characteristics of the material. Corrosion fatigue lives greatly decreased as compared with those in laboratory air. It was also clarified that most of the corrosion fatigue life (70–80%) at the lower stress amplitude is occupied with the period of the corrosion pit growth. Corrosion fatigue lives were evaluated quantitatively by dividing the corrosion fatigue process into the following two periods, i.e. (1) the corrosion pit growth period preceding the crack initiation from the pit and (2) the crack growth period before the Specimen Failure. In the analysis, the law of the corrosion pit growth proposed by authors was used to deal with the above first period. The evaluated results corresponded well to the experimental results.