A computerized digital speckle-interferometry(SPI)system has been set up to determine the in-plane distribution of displacement and strain at crack tip of CF specimens.The principle and the experimental method of this...A computerized digital speckle-interferometry(SPI)system has been set up to determine the in-plane distribution of displacement and strain at crack tip of CF specimens.The principle and the experimental method of this technique are described in detail.The effect of corrosion factors on plastic deformation at crack tip in CF process has been examined by comparing the near-tip strain fields of steel A537 before and after hydrogen charging,and of pure copper before and after applying an anodic current in 3.5% NaCl. The results shows that the clasic finite element mathematical models are not suitable to describe the near-tip deformation under the experimental conditions.Hydrogen charging made the crack tip plasticity decreased for steel A537 and the anodic dissolution enhance the near tip deformation of pure copper specimen.展开更多
In order to further understand the wear mechanisms of cemented carbide cutter head of conical pick, six wornout cutter heads were investigated detailedly through scanning electron microscopy（SEM） and energy dispersi...In order to further understand the wear mechanisms of cemented carbide cutter head of conical pick, six wornout cutter heads were investigated detailedly through scanning electron microscopy（SEM） and energy dispersive spectrometry（EDS）. Abrasion wear and tipping were found to be the main wear mechanisms of the worn out cutter heads. Thermal stress and impact load played important roles in the wearing process of cutter heads. The intermixed mineral particles in the worn out areas aggravated the wear on the surface of cemented carbide. The spherical particles and vine-like structures were found to distribute in the wornout areas arbitrarily, and the compositions of which were detected using EDS.展开更多
文摘A computerized digital speckle-interferometry(SPI)system has been set up to determine the in-plane distribution of displacement and strain at crack tip of CF specimens.The principle and the experimental method of this technique are described in detail.The effect of corrosion factors on plastic deformation at crack tip in CF process has been examined by comparing the near-tip strain fields of steel A537 before and after hydrogen charging,and of pure copper before and after applying an anodic current in 3.5% NaCl. The results shows that the clasic finite element mathematical models are not suitable to describe the near-tip deformation under the experimental conditions.Hydrogen charging made the crack tip plasticity decreased for steel A537 and the anodic dissolution enhance the near tip deformation of pure copper specimen.
基金Funded by the National Natural Science Foundation of China(No.51475346)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20131420120002)the Shanxi Province Science Foundation(No.2013011025-1)
文摘In order to further understand the wear mechanisms of cemented carbide cutter head of conical pick, six wornout cutter heads were investigated detailedly through scanning electron microscopy（SEM） and energy dispersive spectrometry（EDS）. Abrasion wear and tipping were found to be the main wear mechanisms of the worn out cutter heads. Thermal stress and impact load played important roles in the wearing process of cutter heads. The intermixed mineral particles in the worn out areas aggravated the wear on the surface of cemented carbide. The spherical particles and vine-like structures were found to distribute in the wornout areas arbitrarily, and the compositions of which were detected using EDS.
