The brittle–ductile transition(BDT) widely exists in the manufacturing with extremely small deformation scale, thermally assisted machining, and high-speed machining. This paper reviews the BDT in extreme manufacturi...The brittle–ductile transition(BDT) widely exists in the manufacturing with extremely small deformation scale, thermally assisted machining, and high-speed machining. This paper reviews the BDT in extreme manufacturing. The factors affecting the BDT in extreme manufacturing are analyzed, including the deformation scale and deformation temperature induced brittle-to-ductile transition, and the reverse transition induced by grain size and strain rate. A discussion is arranged to explore the mechanisms of BDT and how to improve the machinability based on the BDT. It is proposed that the mutual transition between brittleness and ductility results from the competition between the occurrence of plastic deformation and the propagation of cracks. The brittleness or ductility of machined material should benefit a specific manufacturing process, which can be regulated by the deformation scale, deformation temperature and machining speed.展开更多
Morphology and structure of a faulted zone not only express the present status but also preserve the evidences of early seismo-tectonic occurrences. The present paper aims to assess the morphological as well as subsur...Morphology and structure of a faulted zone not only express the present status but also preserve the evidences of early seismo-tectonic occurrences. The present paper aims to assess the morphological as well as subsurface evidences of early seismo-tectonic occurrences in an earth- quake prone zone of Baromura Hill, Tripura. Tectonically this is a part of Tripura-Mizoram fold belt and fall within Zone V of BIS seismic map. In the present research the tectonic lineaments of Baromura Hill was identified by using satellite data. For that purpose, Landsat TM shortwave in- frared, midwave infrared and near infrared was selected for preparing suitable band combination. A classified thermal infrared was used for final operation. From the remote sensing operation five clear tectonic lineaments were found. During the field work rock samples were collected for labora- tory testing. Thin sections of the rocks show that complex stress pattern was developed during the geological past which caused strong seismo-tectonic occurrences. From the study it can be assessed that though the nature of the paleo-seismic occurrences were almost same but the level of impact varied through spatial and temporal scales due different physical properties and arrangements. It is also clear from the study that the geological evolution of this place is more complex as it seems to be. Tectonic and geomorphic processes worked together through the Tertiary and Quaternary periods and played equally important role for landform evolution.展开更多
基金support from the National Natural Science Foundation of China (Grant No. 51835004)。
文摘The brittle–ductile transition(BDT) widely exists in the manufacturing with extremely small deformation scale, thermally assisted machining, and high-speed machining. This paper reviews the BDT in extreme manufacturing. The factors affecting the BDT in extreme manufacturing are analyzed, including the deformation scale and deformation temperature induced brittle-to-ductile transition, and the reverse transition induced by grain size and strain rate. A discussion is arranged to explore the mechanisms of BDT and how to improve the machinability based on the BDT. It is proposed that the mutual transition between brittleness and ductility results from the competition between the occurrence of plastic deformation and the propagation of cracks. The brittleness or ductility of machined material should benefit a specific manufacturing process, which can be regulated by the deformation scale, deformation temperature and machining speed.
基金University Grants Commission, New Delhi, India for their partial funding (Minor Project) in this research
文摘Morphology and structure of a faulted zone not only express the present status but also preserve the evidences of early seismo-tectonic occurrences. The present paper aims to assess the morphological as well as subsurface evidences of early seismo-tectonic occurrences in an earth- quake prone zone of Baromura Hill, Tripura. Tectonically this is a part of Tripura-Mizoram fold belt and fall within Zone V of BIS seismic map. In the present research the tectonic lineaments of Baromura Hill was identified by using satellite data. For that purpose, Landsat TM shortwave in- frared, midwave infrared and near infrared was selected for preparing suitable band combination. A classified thermal infrared was used for final operation. From the remote sensing operation five clear tectonic lineaments were found. During the field work rock samples were collected for labora- tory testing. Thin sections of the rocks show that complex stress pattern was developed during the geological past which caused strong seismo-tectonic occurrences. From the study it can be assessed that though the nature of the paleo-seismic occurrences were almost same but the level of impact varied through spatial and temporal scales due different physical properties and arrangements. It is also clear from the study that the geological evolution of this place is more complex as it seems to be. Tectonic and geomorphic processes worked together through the Tertiary and Quaternary periods and played equally important role for landform evolution.
