The friction and wear behaviors of Inconel 690 flat against Si3Ni4 ball were investigated using a hydraulic fretting test rig equipped with a liquid container device. The loads of 20-80 N, reciprocating amplitudes of ...The friction and wear behaviors of Inconel 690 flat against Si3Ni4 ball were investigated using a hydraulic fretting test rig equipped with a liquid container device. The loads of 20-80 N, reciprocating amplitudes of 80-200 μm and two different environments （distilled water and hydrazine solution at temperatures from 25 to 90 ℃） were selected. The results show that the ratio of Ft/Fn is lower in distilled water than that in hydrazine solution at the same temperature in the slip regime. Both the ratio of Ft/Fn and wear volume gradually increase with increasing medium temperature under the given normal load and displacement amplitude. Besides the displacement amplitude and load, temperature also plays an important role for wear behavior of Inconel 690 material. The increase of temperature could reduce the concentration of dissolved oxygen, and promote the absorption reaction of hydrazine and dissolved oxygen. As a result, the oxidative corrosion rate is obviously lowered. Abrasive wear and delamination wear are the main mechanisms of Inconel 690 in distilled water. However, in hydrazine solution the cracks accompanied by abrasive wear and delamination wear are the main mechanisms.展开更多
This discussion paper is an attempt to consider new ideas about the nature of explosive phenomena of the meteorite bodies in the Earth＇s atmosphere. Authors attract approaches, based on the concepts of physics of com...This discussion paper is an attempt to consider new ideas about the nature of explosive phenomena of the meteorite bodies in the Earth＇s atmosphere. Authors attract approaches, based on the concepts of physics of combustion, explosion and detonation in order to explain the explosive collapse of the meteorite. Authors believe that the meteorite explosion may be the result of gas-detonation mechanism of overheated meteoric bodies explosive boiling-up （the ＂vapor explosion＂）, accompanied by the formation of a supersonic front of shock wave. The considered hypothesis regarding the role of the ＂vapor explosion＂ in geological disasters can be used to explain the mechanisms of explosive phenomena in Volcanology： （1） With respect to the description of nature of phreatic eruptions; （2） for interpretation of dynamic regularities of the volcano crater opening and the subsequent shock-wave emission of steam-gas ＂fountain＂ to a height of several kilometers with fragments of magma and rocks as a result of the ＂vapor explosion＂ of overheated magma mass under the dome of the volcano.展开更多
This paper demonstrates the use of a commercial simulator as a tool with which to optimize the SAGD （steam-assisted gravity drainage） start-up phase process. The factors affecting the start-up phase are the prime ta...This paper demonstrates the use of a commercial simulator as a tool with which to optimize the SAGD （steam-assisted gravity drainage） start-up phase process. The factors affecting the start-up phase are the prime targets. Among the key investigated factors are wellbore geometry effects, reservoir heterogeneity and circulation phase length. Each of the parameters was investigated via steam chamber development observation along the well pair length and the cross sections in the mid, toe and heel areas. In addition, the cumulative recovery in given time, steam-to-oil ratio and CDOR （calendar day oil rate） production data are used to backup the observations produced in the simulated model. Furthermore, an additional component developed during the research is a statistical modification of a layer cake model with which to create a heterogeneous reservoir to represent real reservoir conditions, based on Monte Carlo＇s simulation.展开更多
Modeling vapor pressure is crucial for studying the moisture reliability of microelectronics, as high vapor pressure can cause device failures in environments with high temperature and humidity. To minimize the impact...Modeling vapor pressure is crucial for studying the moisture reliability of microelectronics, as high vapor pressure can cause device failures in environments with high temperature and humidity. To minimize the impact of vapor pressure, a super-hydrophobic(SH) coating can be applied on the exterior surface of devices in order to prevent moisture penetration. The underlying mechanism of SH coating for enhancing device reliability, however, is still not fully understood. In this paper, we present several existing theories for predicting vapor pressure within microelectronic materials. In addition, we discuss the mechanism and effectiveness of SH coating in preventing water vapor from entering a device, based on experimental results. Two theoretical models, a micro-mechanics-based whole-field vapor pressure model and a convection-diffusion model, are described for predicting vapor pressure. Both methods have been successfully used to explain experimental results on uncoated samples. However, when a device was coated with an SH nanocomposite, weight gain was still observed, likely due to vapor penetration through the SH surface. This phenomenon may cast doubt on the effectiveness of SH coatings in microelectronic devices. Based on current theories and the available experimental results, we conclude that it is necessary to develop a new theory to understand how water vapor penetrates through SH coatings and impacts the materials underneath. Such a theory could greatly improve microelectronics reliability.展开更多
基金Project(51075342)supported by the National Natural Science Foundation of China
文摘The friction and wear behaviors of Inconel 690 flat against Si3Ni4 ball were investigated using a hydraulic fretting test rig equipped with a liquid container device. The loads of 20-80 N, reciprocating amplitudes of 80-200 μm and two different environments （distilled water and hydrazine solution at temperatures from 25 to 90 ℃） were selected. The results show that the ratio of Ft/Fn is lower in distilled water than that in hydrazine solution at the same temperature in the slip regime. Both the ratio of Ft/Fn and wear volume gradually increase with increasing medium temperature under the given normal load and displacement amplitude. Besides the displacement amplitude and load, temperature also plays an important role for wear behavior of Inconel 690 material. The increase of temperature could reduce the concentration of dissolved oxygen, and promote the absorption reaction of hydrazine and dissolved oxygen. As a result, the oxidative corrosion rate is obviously lowered. Abrasive wear and delamination wear are the main mechanisms of Inconel 690 in distilled water. However, in hydrazine solution the cracks accompanied by abrasive wear and delamination wear are the main mechanisms.
文摘This discussion paper is an attempt to consider new ideas about the nature of explosive phenomena of the meteorite bodies in the Earth＇s atmosphere. Authors attract approaches, based on the concepts of physics of combustion, explosion and detonation in order to explain the explosive collapse of the meteorite. Authors believe that the meteorite explosion may be the result of gas-detonation mechanism of overheated meteoric bodies explosive boiling-up （the ＂vapor explosion＂）, accompanied by the formation of a supersonic front of shock wave. The considered hypothesis regarding the role of the ＂vapor explosion＂ in geological disasters can be used to explain the mechanisms of explosive phenomena in Volcanology： （1） With respect to the description of nature of phreatic eruptions; （2） for interpretation of dynamic regularities of the volcano crater opening and the subsequent shock-wave emission of steam-gas ＂fountain＂ to a height of several kilometers with fragments of magma and rocks as a result of the ＂vapor explosion＂ of overheated magma mass under the dome of the volcano.
文摘This paper demonstrates the use of a commercial simulator as a tool with which to optimize the SAGD （steam-assisted gravity drainage） start-up phase process. The factors affecting the start-up phase are the prime targets. Among the key investigated factors are wellbore geometry effects, reservoir heterogeneity and circulation phase length. Each of the parameters was investigated via steam chamber development observation along the well pair length and the cross sections in the mid, toe and heel areas. In addition, the cumulative recovery in given time, steam-to-oil ratio and CDOR （calendar day oil rate） production data are used to backup the observations produced in the simulated model. Furthermore, an additional component developed during the research is a statistical modification of a layer cake model with which to create a heterogeneous reservoir to represent real reservoir conditions, based on Monte Carlo＇s simulation.
基金the support of the National High-Tech Research and Development Program of China (863 Program) (2015AA03A101)
文摘Modeling vapor pressure is crucial for studying the moisture reliability of microelectronics, as high vapor pressure can cause device failures in environments with high temperature and humidity. To minimize the impact of vapor pressure, a super-hydrophobic(SH) coating can be applied on the exterior surface of devices in order to prevent moisture penetration. The underlying mechanism of SH coating for enhancing device reliability, however, is still not fully understood. In this paper, we present several existing theories for predicting vapor pressure within microelectronic materials. In addition, we discuss the mechanism and effectiveness of SH coating in preventing water vapor from entering a device, based on experimental results. Two theoretical models, a micro-mechanics-based whole-field vapor pressure model and a convection-diffusion model, are described for predicting vapor pressure. Both methods have been successfully used to explain experimental results on uncoated samples. However, when a device was coated with an SH nanocomposite, weight gain was still observed, likely due to vapor penetration through the SH surface. This phenomenon may cast doubt on the effectiveness of SH coatings in microelectronic devices. Based on current theories and the available experimental results, we conclude that it is necessary to develop a new theory to understand how water vapor penetrates through SH coatings and impacts the materials underneath. Such a theory could greatly improve microelectronics reliability.
