The mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering (SPS) were investigated. The results showed that the densities of the sintered composites gradually increa...The mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering (SPS) were investigated. The results showed that the densities of the sintered composites gradually increased with increasing sintering temperature and that the highest microhardness and compressive strength were achieved in the specimen sintered at 450A degrees C. CNTs dispersed uniformly in the Al-Si10Mg matrix when the addition of CNTs was less than 1.5wt%. However, when the addition of CNTs exceeded 1.5wt%, the aggregation of CNTs was clearly observed. Moreover, the mechanical properties (including the densities, compressive strength, and microhardness) of the composites changed with CNT content and reached a maximum value when the CNT content was 1.5wt%. Meanwhile, the minimum average friction coefficient and wear rate of the CNT/AlSi10Mg composites were obtained with 1.0wt% CNTs.展开更多
An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the...An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.展开更多
AI 5083//10 wt% SiCp nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering （SPS）. Nano composites produced via this method exhibited near-theoretical density w...AI 5083//10 wt% SiCp nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering （SPS）. Nano composites produced via this method exhibited near-theoretical density while retaining the nano-grained features. X-ray diffraction （XRD） analysis indicated that the crystalline size of the ball milled AI 5083 matrix was observed to be～25 nm and it was coarsened up to～30 nm after SPS. Nano indentation results of nano composites demonstrated a high hardness of～280 HV with an elastic modulus of 126 GPa. Wear and friction characteristics with addition of SiCp reinforcement exhibited significant improvement in terms of coefficient of friction and specific wear rate to that of nano structured AI 5083 alloy. The reduction in specific wear rate in the nanocomposite was mainly due to the change of wear mechanism from adhesive to abrasive wear with the addition of SiCp which resulted in high hardness associated with nano-grained microstructure.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,China) under Grant Number of 51405467Chongqing Research of Application Foundation and Advanced Technology(project No.cstc2016jcyj A0016)the Key Program of the Chinese Academy of Sciences(No.KGZD-EW-T0)
文摘The mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering (SPS) were investigated. The results showed that the densities of the sintered composites gradually increased with increasing sintering temperature and that the highest microhardness and compressive strength were achieved in the specimen sintered at 450A degrees C. CNTs dispersed uniformly in the Al-Si10Mg matrix when the addition of CNTs was less than 1.5wt%. However, when the addition of CNTs exceeded 1.5wt%, the aggregation of CNTs was clearly observed. Moreover, the mechanical properties (including the densities, compressive strength, and microhardness) of the composites changed with CNT content and reached a maximum value when the CNT content was 1.5wt%. Meanwhile, the minimum average friction coefficient and wear rate of the CNT/AlSi10Mg composites were obtained with 1.0wt% CNTs.
文摘An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.
基金supported by Council of Scientific and Industrial Research(CSIR)under its network project(CSIR-NWP-51)entitled"Nanostructured Advanced Materials(NAM)"
文摘AI 5083//10 wt% SiCp nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering （SPS）. Nano composites produced via this method exhibited near-theoretical density while retaining the nano-grained features. X-ray diffraction （XRD） analysis indicated that the crystalline size of the ball milled AI 5083 matrix was observed to be～25 nm and it was coarsened up to～30 nm after SPS. Nano indentation results of nano composites demonstrated a high hardness of～280 HV with an elastic modulus of 126 GPa. Wear and friction characteristics with addition of SiCp reinforcement exhibited significant improvement in terms of coefficient of friction and specific wear rate to that of nano structured AI 5083 alloy. The reduction in specific wear rate in the nanocomposite was mainly due to the change of wear mechanism from adhesive to abrasive wear with the addition of SiCp which resulted in high hardness associated with nano-grained microstructure.
