Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size ...Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot times.To quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated.The results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian distribution.Compared with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy absorption.Besides,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first shot.More concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots.展开更多
A high-entropy alloy–ceramic gradient composite of TiC–TiB_2/75vol% Al_(0.3) CoCrFe Ni was successfully prepared by combustion synthesis under an ultra-high gravity field, which is a low-cost method with high effici...A high-entropy alloy–ceramic gradient composite of TiC–TiB_2/75vol% Al_(0.3) CoCrFe Ni was successfully prepared by combustion synthesis under an ultra-high gravity field, which is a low-cost method with high efficiency. The ceramic particles were gradient distributed in the Al_(0.3) CoCrFe Ni matrix, and the hardness of the composite material gradually decreased along the thickness direction. The anti-penetration performance of the gradient composites was simulated using the ANSYS/LS-DYNA explicit simulation program. The results demonstrate that the distribution of the ceramic particles strongly affected the mechanical properties and the anti-penetration performance of the composites. With the same total ceramic volume fraction, the gradient composites exhibit better anti-penetration performance than the corresponding ceramic–metal interlayer composites. The more uneven the ceramic distribution, the greater the elastic modulus and yield stress of the surface layer and, thus, the better the anti-penetration performance.展开更多
新疆天湖东遗址是目前西北地区发现的年代最早的绿松石采矿遗址,它的发现为研究我国西北地区古代绿松石来源提供了直接的考古学证据。开展天湖东绿松石矿物学特征研究,可为判断该遗址出产绿松石的产源特点和流布提供基础科学数据。鉴于...新疆天湖东遗址是目前西北地区发现的年代最早的绿松石采矿遗址,它的发现为研究我国西北地区古代绿松石来源提供了直接的考古学证据。开展天湖东绿松石矿物学特征研究,可为判断该遗址出产绿松石的产源特点和流布提供基础科学数据。鉴于此,采用偏光显微镜、扫描电子显微镜、X射线粉末衍射、电子探针、拉曼光谱等测试方法开展绿松石样品的表面微形貌、矿物组成、化学成分、拉曼光谱等矿物学和谱学特征的研究。结果表明,新疆天湖东绿松石样品多呈微晶鳞片状及微晶纤维状结构,主要以长柱状、针状、板状相互交织结晶生长,杂质可见石英与黑云母,且出产少见的磷灰石。天湖东绿松石与黑山岭绿松石的拉曼光谱测试结果无明显区别,但电子探针检测的主量化学成分结果显示,天湖东绿松石的Al 2 O 3、P 2 O 5的含量均低于标准值,而黑山岭绿松石却均高于标准值,二者在此存在明显差异。展开更多
基金financially supported by the National Key Research&Development Project(2017YFB1103505)the Military Logistics Research Program(XXXC002)of China。
文摘Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot times.To quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated.The results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian distribution.Compared with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy absorption.Besides,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first shot.More concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots.
基金financially supported by the Fundamental Research Funds for the Central Universities of China (FRF-GF-17-B21)
文摘A high-entropy alloy–ceramic gradient composite of TiC–TiB_2/75vol% Al_(0.3) CoCrFe Ni was successfully prepared by combustion synthesis under an ultra-high gravity field, which is a low-cost method with high efficiency. The ceramic particles were gradient distributed in the Al_(0.3) CoCrFe Ni matrix, and the hardness of the composite material gradually decreased along the thickness direction. The anti-penetration performance of the gradient composites was simulated using the ANSYS/LS-DYNA explicit simulation program. The results demonstrate that the distribution of the ceramic particles strongly affected the mechanical properties and the anti-penetration performance of the composites. With the same total ceramic volume fraction, the gradient composites exhibit better anti-penetration performance than the corresponding ceramic–metal interlayer composites. The more uneven the ceramic distribution, the greater the elastic modulus and yield stress of the surface layer and, thus, the better the anti-penetration performance.
文摘新疆天湖东遗址是目前西北地区发现的年代最早的绿松石采矿遗址,它的发现为研究我国西北地区古代绿松石来源提供了直接的考古学证据。开展天湖东绿松石矿物学特征研究,可为判断该遗址出产绿松石的产源特点和流布提供基础科学数据。鉴于此,采用偏光显微镜、扫描电子显微镜、X射线粉末衍射、电子探针、拉曼光谱等测试方法开展绿松石样品的表面微形貌、矿物组成、化学成分、拉曼光谱等矿物学和谱学特征的研究。结果表明,新疆天湖东绿松石样品多呈微晶鳞片状及微晶纤维状结构,主要以长柱状、针状、板状相互交织结晶生长,杂质可见石英与黑云母,且出产少见的磷灰石。天湖东绿松石与黑山岭绿松石的拉曼光谱测试结果无明显区别,但电子探针检测的主量化学成分结果显示,天湖东绿松石的Al 2 O 3、P 2 O 5的含量均低于标准值,而黑山岭绿松石却均高于标准值,二者在此存在明显差异。
