现代炸药—乳胶炸药和重铵油炸药

乳胶体是分散相被全部分散于连续相之中的两相体系。乳胶炸药是由燃料油和氧化剂所组成的混合物。氧化剂是硝酸盐类,燃料油大都是无机的或有机的碳氢化合物。氧化剂与燃料油的配比约为10:1。电子显微镜观察乳胶体的结构表明,被     

相容剂对PA6/PE基体-微纤型共混纤维形态结构的调控

以PA6／PE非相容体系进行了共混纺丝，可得到以PA6为分散相，PE为连续相的基体微纤型结构，再用有机溶剂溶除PE便可制得PA6的超细纤维。将相容剂PO－g－MAH添加于PA6／PE共混纺丝体系，可对其基体－微纤型形态结构进行调控。添加适量的相容剂可增加共混组成物间的亲和性，改善纺丝过程的可纺性；在本研究的添加量范围内，随相容剂添加量的增加，共混纤维中分散相平均直径减小，尺寸均匀提高。过量地添加相容剂会使共混组分两相间作用力过强，这对改善其中某组分的性能有利，但对本研究的内容是不利的，会导致基体－微纤型共混纤维难于溶解剥离为超细纤维，DSC、IR及SEM的分析结果支持了这一结论。     

共轴微通道水相微球制备

本文以竖直共轴微通道为研究对象,采用去离子水为分散相、5W-20润滑油为连续相,二者在微通道内形成两相流,在管外收集到单分散水相微球,分散相流量Qd的变化范围6ml/h~84ml/h,连续相流量Qc的变化范围6ml/h~192ml/h。发现在以连续相流量Qc为横坐标、分散相流量Qd为纵坐标的水相微球直径图中,单分散水相微球的形成区域存在一条穹顶形边界。单分散的水相微球分布在此边界下部,随着连续相流量Qc的增加,单分散水相微球的形成边界呈现出先上升后下降的趋势。形成单分散水相微球的Qd60ml/h。单分散水相微球直径与两相流量比(Qd/Qc)呈现出对数增加的关系。     

尼龙11/MBS/环氧树脂共混合金的力学性能和增韧机理

对尼龙11共混合金体系的力学性能进行了考察,对于尼龙11／EXL－2691核－壳冲击改性剂／相容剂三元共混合金体系加入环氧树脂后,分散相0冲击改性剂在尼龙11基体中的分布更加均匀,两相的相容性提高,但分散相粒子粒径并未随环氧树脂用量的增加而减小,加入1％的环氧树脂后,共混合金体系冲击强度最大,分散相粒子粒径最小,体系的断裂强度随着环氧树脂用量的增加而增大,伸长率则降低,此共混合金体系的增韧机理为分散相引发银纹机理。     

两相不相容共混体系的亚微形态及其影响因素

本文讨论了“海岛”两相分散、分散相纤维化、分散相层化等三种亚微形态的形成条件以及与共混物组成、组份粘度比、加工工艺和增容剂之间的关系。     

SMA增容ABS/PBT共混体系的形态和力学性能——共混过程对体系的影响

以苯乙烯-马来酸酐共聚物(SMA)为增容剂,研究了共混工艺对ABS/PBT共混物聚集态结构和力学性能的影响。结果表明,SMA先与ABS共混再与PBT共混,共混物的分散相尺寸最小、分布最均匀,优于SMA先与PBT共混再与ABS共混的方法。ABS与PBT共混物的相容性差,加入反应性相容剂SMA后,PBT分散相尺寸变小且均匀地分散于ABS中,显著改善了ABS/PBT共混物的冲击、拉伸性能。共混物的聚集态结构强烈地受共混工艺的影响。     

HDPE／PET层状分散合金亚微相态与相容性关系

通过选择相容剂种类及添加量，改变了HDPE/PET共混体系中分散相的尺寸及形态从而获得了以PET为分散相的各种层状分散相态研究了共混体系相容性与相态之间的关系结果表明：PET层化趋势随体系的相容性增大而增强但当相容剂含量超过一定值时，层状分散相态从中心处开始被破坏．根据这一现象，提出了层化相容区的概念     

熔体的粘性和弹性对LDPE／PS共混物形态的影响

研究了粘性和弹性对低密度聚乙烯／聚苯乙烯共混物形态的影响。结果表明，不相容聚合物在均匀剪切流动中的分散程度以及分散相的形状与组分的粘度比、相对弹性和体积分数有关。当分散相的粘性和弹性较基相大得多时，随分散相的体积分数增加，球状的液滴形成葡萄串状。若两组分的粘性和弹性相当，在适中的混合比下，分散相产生高度变形。不管组分的粘反比和弹性比大小，若分散相的体积分数非常低，共混物的主要形态皆为分散相的球状液滴分散在基体中。     

尼龙6/聚苯乙烯共混物融合缝的形态及其对力学性能的影响

采用扫描电镜(SEM)、力学性能测定,研究了尼龙6／聚苯乙烯(PA-6／PS)共混体系融合缝的形态及力学性能．鲒果表明,分散相和连续相的粘度比对融合缝的形态有重要影响．当η分散相／η连续相＞1时,融合缝处分散相的形态不同于本体．融合缝处分散相沿融合缝取向;当η分散相／η连续相＜1时．融合缝处分散相的形态与本体形态相似．均以球形粒子分散于基体中。融合缝的存在使共混体系的力学性能有较大下降,主要由融合缝处分散相形态所致。     

聚丙烯接枝物反应挤出增容PP/PA6共混物的形态结构

采有PP熔融接枝MAH和不饱和羧酸混合单体通过反应挤出增容PP/PA6共混物，研究了增容共混物的形态结构。SEM、TEM观察表明，接枝物能明显降低共混物的分散相尺寸，改善体系的分散状况，提高共混物两相的相容性；增容共混物的两相界面结合改善，相界面变得模糊。WAXD、DSC测试表明，用该接枝物增容后的共混物，组分的Xc下降，分散相微晶尺才减小。研究结果表明该接枝物是PP/PA6共混体系的有效增容剂。     

Massive Si Phase and Its Growth Mechanism in Al-Si Casting Alloy

Optical microscope and scanning electron microscope were used to observe the microstructure of the AI-11.6%Si and AI-11.6%Si-0.4%Mg alloys and the morphology of the massive silicon particles. It is found that the massive silicon phase, observed in the unfully modified alloys with 0.010%Sr, disappears completely in the alloys fully modified with 0.020%Sr. The serrations and reentrant edges shown in the massive silicon particles with the conventional casting indicate that the TPRE mechanism plays an important role in the growth of the massive silicon phase. The ripples and steps suggest that the "lateral microscopic growth" may be another operating mechanism.     

HPVC／PP共混改性研究：Ⅲ低分子量反应性化合物作相容剂

采用低分子量反应性化合物作相容剂，即化学交联体系来改善ＨＰＶＣ／ＰＰ共混物的相容性。考察了在不同共混比下，不同化学交联体系对共混物力学性能的影响，并观察了共混物的微观形态。结果表明，采用低分子量反应性化合物作相容剂，共混物的拉伸强度提高，但冲击强度无改善。分散相尺寸减小，相间粘接得到改善。并比较了３种增容方法的效果，发现ＣＰＥ是ＨＰＶＣ／ＰＰ共混物的最佳相容剂。     

Microstructural investigation of a rapidly solidified Ti-6Al-4V-1B-0.5Y alloy

A Ti-6Al-4V-1B-0.5Y (wt%) alloy has been prepared by consolidation of the melt-spun alloy fibres. The microstructures of the melt-spun fibre and the consolidated alloy were examined by different techniques. It was found that in the consolidated alloy, titanium boride and yttrium oxide particles have a refined particle size and a uniform distribution in the (+) matrix compared with the microstructure of the same alloy obtained by conventional ingot metallurgy. The boride phase in the consolidated alloy mainly has a needle-shaped morphology and has been identified by electron diffraction to be orthorhombic TiB with a B27 structure, while the yttrium oxide has a cuboidal morphology and has been identified as bcc Y₂O₃. Detailed TEM examination also revealed that yttrium addition has a strong influence on the TiB morphology by comparing the microstructures of Ti-6Al-4V-1B alloys with and without yttrium addition. Under similar processing conditions, the TiB phase in the consolidated alloys without yttrium addition mainly has a nearly equiaxed morphology with a finer particle size, while the TiB phase in the consolidated alloy with yttrium addition will mainly have a needle-shaped morphology. This effect of yttrium addition on the TiB morphology has been discussed in terms of heterogeneous nucleation and the reduced undercooling.     

形态稳定相变材料聚乙二醇/聚酰胺6共混物的制备及性能

以聚醚酯酰胺(PEEA)为相容剂,以溶液共混的方法制备了形态稳定的聚乙二醇(PEG)/聚酰胺6(PA6)相变材料,对材料的形态结构、固-固相变、热性能及相变实质进行了研究。结果表明,制备形态稳定的相变材料(PCM),PEG的最大添加量为80%(质量分数);材料的相变温度及相变焓随PEG质量分数的增加和分子质量的增大而提高;材料在相变温度下发生了固-固相转变,其实质是PEG在相变温度下由结晶态到无定型态的相互转变,材料在循环加热的条件下也能一直保持稳定的形态,无熔化泄漏。     

Thermodynamically reversible and irreversible control on morphology of multiphase systems

Morphology and properties of polymer alloys can be controlled by thermodynamically reversible (structure freeze-in) or irreversible (structure lock-in) processes via simultaneously manipulating miscibility, mechanisms of phase separation, glass transition (structural relaxation), and cure kinetics of polymer systems. Using phase diagrams consisting of binodal and spinodal curves, the morphology of epoxy/carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) systems can be controlled by the mechanism of nucleation and growth or by spinodal decomposition. We have found that the particle size of the rubber reinforcement in epoxies is affected by the mechanisms of phase separation. Phase separation by nucleation and growth gives larger rubber particles than the corresponding phase separation by spinodal decomposition. This contrast in the morphology development is the consequence of controlling phase separation through chemorheological behaviour. Modification of the phase separation kinetics in epoxy/CTBN systems was extremely effective at altering both morphology and properties of these alloys. This technique offers a means to shift the glass transition temperature of the rubber-rich phase while leaving the glass transition temperature of the epoxy-rich phase intact. Such control over morphology is the key to ultimately controlling material properties.     

Quantification of the evolution of the 3D intermetallic structure in a 6005A aluminium alloy during a homogenisation treatment

In the case of aluminium alloys, a postcasting homogenisation heat treatment is applied in order to improve extrudability. During this homogenisation, a phase transformation occurs and the intermetallic structure evolves from an interconnected network of plate-like structures into a more discrete distribution of particles. The morphology of these intermetallics has been the subject of many studies employing conventional 2D characterisation. However, recently, it has been shown that 2D analyses can be misleading and that techniques suitable for quantification of 3D structures can provide more reliable information.

In this study, serial sectioning and 3D reconstruction techniques were used to reveal the three-dimensional morphology, connectivity and distribution of the intermetallic microstructure, and the evolution of these parameters during homogenisation. The qualitative and quantitative analysis of the reconstructed intermetallic microstructures, with particular reference to the determination of the spatial distribution of the absolute, mean and Gaussian curvature is discussed.     

AlCoCrNiSi_x高熵合金微观组织结构与力学性能

通过XRD,SEM,EDS分析和显微硬度测试,系统研究了Si含量对AlCoCrNiSix高熵合金铸态组织的相结构变化、微观组织形貌特征和力学性能。结果表明:随Si含量的增加,合金相结构由单一的bcc1固溶体结构逐步转化为bcc1+bcc2结构共存,其中bcc1为AlNi基的固溶体,bcc2为CrSi固溶体。随Si含量的增加,合金的铸态组织由枝晶形态向胞状形态转变。微观组织中Al,Ni主要存在于枝晶内,Si则偏析于枝晶间。Si具有显著提高合金硬度的作用,硬度最大值达到HV991。     

新型增容剂（A）对聚苯醚／聚酰胺共混体系的影响

合成了一种用马来酸酐改性的低分子聚烯烃(A)并将A作为PPO/PA共混体系的一种新型增容剂。从物理机械性能和形态结构两方面研究了A对PPO/PA共混体系的增容效果。结果表明,增容剂A与文献报导的PPO/PA体系的某些增容剂相比,除用量少、增容效果好外,还兼具耐热改性剂和流动改性剂的功能,即A是一种多功能的改性剂,它是通过使PPO/A与PA形成界面过渡层而实现其增容作用的。     

Morphologies of Si phase and La-rich phase in as-cast hypereutectic Al–Si–xLa alloys

In the present study, the diversified morphologies of Si phase and La-rich phase in as-casted hypereutectic Al–Si–xLa alloys are presented and investigated. The morphological features were examined using conventional optical microscopy and SEM for observations conducted on the optical samples and deep-etched samples, respectively. The results show that primary Si crystals show several morphologies, such as feathery, star-shaped, faceted polygonal, platelet and so on. There are three types of fivefolded Si crystals existing in the present study, fivefold symmetry as radial growth alone: thin-branched, coarse-branched and well-defined star-shaped growing from the preferred growth from the tips of branches. The eutectic Si in unmodified Al–Si alloys appears only in fibrous morphology, while discrete and interconnected coral and rodlike eutectic Si particles were observed in alloys with the addition of La. The La-rich phase also grows into a variety of morphologies, such as needlelike, broken rodlike in pores, spherical, and flat platelet. In optical microscopy, La-rich phase is observed to envelope some small polygonal Si crystals.