英语高手请进:俺是菜鸟,帮忙翻译一下,谢谢啊!急啊!
来源:学生作业帮 编辑:作业帮 分类:英语作业 时间:2024/08/28 21:54:52
英语高手请进:俺是菜鸟,帮忙翻译一下,谢谢啊!急啊!
(1)The mechanical behaviour of undirectional and 2D-laminate coal-tar pitch-based carbon/carbon composites was investigated in tension and bending conditions (3 and 4-point loading tests) at room temperature. One of the major drawbacks of such highly anisotropic structures is their poor resistance to delamination (high sensitivity to local shear components). In order to improve their interlaminar shear strength, carbon blacks were introduced between the unidirectional plies of the 2D-C/C specimens prior to the pitch infiltration. The damage and the failure mechanisms were identified by microscope observations on both UD and 2D-C/C composites. Two families of damage modes were identified, involving limited interfibre cracks and inter-layer delamination cracks homogeneously distributed within the composite. The fracture process is assigned to the propagation of the macrocrack in the failure envelope through a large intra and interlayer delamination process interrupted by fibres /bundles fracture. Acoustic emission analysis was performed during the tests. An approach using a combination of acoustic emission waveform parameters as indicators of the physical damage of the composite is discussed.
(2)The isotropic phase isolated from a thermally treated coal-tar pitch was studied as a possible precursor for carbon fibres.Extraction with different solvents was performed in order to increase its softening point and so enable higher stabilisation temperatures to be used, with a significant reduction in time. The extraction conditions were selected studying the softening temperatures of the residues, the results of their thermogravimetric analysis and reactivity in air studied by means of differential scanning calorimetry. The residue obtained with a mixture of 40% acetone–60% acetonitrile was found to be the most suitable precursor for the fibres. The carbonised fibres showed a homogeneous surface and diameter, and had tensile properties comparable to other isotropic fibres described in the literature.
(3)Unidirectional carbon/carbon composites were developed using high-pressure impregnation/carbonization technique with PAN and pitch based carbon fibers of varying microstructure as reinforcements and different types of pitches as matrix precursors. The composites have been given final heat treatment to 2500–2700 \1C. Microstructure of these composites has been evaluated using scanning electron
microscope and polarized light optical microscope. Thermophysical properties, i.e., thermal conductivity, coefficient of thermal expansion and specific heat have been evaluated. It is found that the type of fibers and matrix present in the composites influences the absorption (specific heat) and transmission (conductivity) of thermal energy. The temperature dependence of thermal diffusion, specific heat, thermal
conductivity and coefficient of thermal expansion has been studied and correlated with microstructure of carbon/carbon composites.
(1)The mechanical behaviour of undirectional and 2D-laminate coal-tar pitch-based carbon/carbon composites was investigated in tension and bending conditions (3 and 4-point loading tests) at room temperature. One of the major drawbacks of such highly anisotropic structures is their poor resistance to delamination (high sensitivity to local shear components). In order to improve their interlaminar shear strength, carbon blacks were introduced between the unidirectional plies of the 2D-C/C specimens prior to the pitch infiltration. The damage and the failure mechanisms were identified by microscope observations on both UD and 2D-C/C composites. Two families of damage modes were identified, involving limited interfibre cracks and inter-layer delamination cracks homogeneously distributed within the composite. The fracture process is assigned to the propagation of the macrocrack in the failure envelope through a large intra and interlayer delamination process interrupted by fibres /bundles fracture. Acoustic emission analysis was performed during the tests. An approach using a combination of acoustic emission waveform parameters as indicators of the physical damage of the composite is discussed.
(2)The isotropic phase isolated from a thermally treated coal-tar pitch was studied as a possible precursor for carbon fibres.Extraction with different solvents was performed in order to increase its softening point and so enable higher stabilisation temperatures to be used, with a significant reduction in time. The extraction conditions were selected studying the softening temperatures of the residues, the results of their thermogravimetric analysis and reactivity in air studied by means of differential scanning calorimetry. The residue obtained with a mixture of 40% acetone–60% acetonitrile was found to be the most suitable precursor for the fibres. The carbonised fibres showed a homogeneous surface and diameter, and had tensile properties comparable to other isotropic fibres described in the literature.
(3)Unidirectional carbon/carbon composites were developed using high-pressure impregnation/carbonization technique with PAN and pitch based carbon fibers of varying microstructure as reinforcements and different types of pitches as matrix precursors. The composites have been given final heat treatment to 2500–2700 \1C. Microstructure of these composites has been evaluated using scanning electron
microscope and polarized light optical microscope. Thermophysical properties, i.e., thermal conductivity, coefficient of thermal expansion and specific heat have been evaluated. It is found that the type of fibers and matrix present in the composites influences the absorption (specific heat) and transmission (conductivity) of thermal energy. The temperature dependence of thermal diffusion, specific heat, thermal
conductivity and coefficient of thermal expansion has been studied and correlated with microstructure of carbon/carbon composites.
(1)undirectional和二维层压煤焦油沥青基炭/炭,考察了紧张和弯曲在室温条件下(3和4点荷载试验)复合材料的力学行为.这类高度各向异性结构的主要缺点之一是他们贫困的抗分层(高灵敏度当地剪切组件).为了改善他们的层间剪切强度,炭黑之间的单向介绍了二维碳/碳标本前铺层沥青渗透.的破坏和失效机理进行鉴定都有UD和二维炭/炭复合材料的显微镜观察.两种模式的家庭确定了损害,涉及有限interfibre裂纹和层间脱层裂纹均匀分布在复合材料.断裂过程是分配给在信封macrocrack繁殖失败,通过一个大区域内和层间分层的纤维中断/束断裂过程.声发射分析测试过程中执行.一种方法使用了声发射作为复合材料的物理损坏指标波形参数组合进行了讨论.
(2)从各向同性相热处理煤沥青分离的研究用于不同碳前驱体溶剂fibres.Extraction可能进行,以提高其软化点和高稳定的温度,以便使被用来与一,在时间显着减少.萃取条件进行了选择学习的残留物的软化温度,在由差示扫描量热分析手段研究了空气中的热重分析和反应的结果.残留物获得了40%的丙酮,乙腈60%被发现是最合适的纤维的先驱.碳化纤维的表面呈均匀和直径,并媲美的文学描述的各向同性纤维的拉伸性能.
(3)单向碳/碳复合材料的制作使用了高压浸渍/与PAN和音高不同的增援和前体为基体显微组织不同类型的球场基碳纤维碳化技术.该复合材料已获得最终热处理2500至2700年?长这些复合材料的微观结构进行了评价,用扫描电子
偏光显微镜和光学显微镜.热物理性能,即热传导,热膨胀系数和比热进行了评价.它是发现,纤维类型和复合材料基体目前影响吸收(比热)和传输(传导热能).的热扩散,比热,热温度依赖性
电导率和热膨胀系数进行了研究,并与炭结构/炭复合材料的相关性.
凑活看吧我也不太懂
(2)从各向同性相热处理煤沥青分离的研究用于不同碳前驱体溶剂fibres.Extraction可能进行,以提高其软化点和高稳定的温度,以便使被用来与一,在时间显着减少.萃取条件进行了选择学习的残留物的软化温度,在由差示扫描量热分析手段研究了空气中的热重分析和反应的结果.残留物获得了40%的丙酮,乙腈60%被发现是最合适的纤维的先驱.碳化纤维的表面呈均匀和直径,并媲美的文学描述的各向同性纤维的拉伸性能.
(3)单向碳/碳复合材料的制作使用了高压浸渍/与PAN和音高不同的增援和前体为基体显微组织不同类型的球场基碳纤维碳化技术.该复合材料已获得最终热处理2500至2700年?长这些复合材料的微观结构进行了评价,用扫描电子
偏光显微镜和光学显微镜.热物理性能,即热传导,热膨胀系数和比热进行了评价.它是发现,纤维类型和复合材料基体目前影响吸收(比热)和传输(传导热能).的热扩散,比热,热温度依赖性
电导率和热膨胀系数进行了研究,并与炭结构/炭复合材料的相关性.
凑活看吧我也不太懂