铸铁凝固过程中石墨形态的转变

用热解石墨籽晶在含变质元素铈的碳过饱和铁液中的外延生和共晶成分铸铁在定向凝固过程中加入变质元素的方法分别研究了初生石墨和共晶石墨在生长过程中的形态变化。     

Fabrication of niobium doped Pb（Zr, Ti）O3 fibers by viscous polymer processing

A technique based on viscous polymer processing （VPP） was described, which can produce high ceramic content green fibers. PZT-5 ceramic powders were ball milled to get high dispersibility. The slurry prepared for VPP was a composition of PZT-5 powder, PVA binder and glycerin. High ceramic content PZT-5 fibers were extruded with the slurry. The results show that the ceramic powders have fine mean particle size of 0.54 pan, high specific surface area of 3.55 m^2/g and zeta potential of 8.81 mV after 16 h milling. The fibers sintered at 1 280 ℃ for 4 h have pure perovskite structure and grains of 2-5 μm in size, with little pores or cracks. The ultimate tensile strength of sintered fibers is up to 13.84 MPa compared with 2.88 MPa of green fibers. The remnant polarization （Pr） and coercive field （Ec） of the fibers are 50.65 μC/cm^2 and 2.45 kV/mm, respectively. This fiber can withstand an electric field of 9 kV/mm higher than the ceramic （5 kV/mm）, which shows high directional and compact qualities.     

微孔硅酸钙柔性隔热材料的显微结构和导热性能

微孔硅酸钙柔性隔热材料由以硬硅钙石针状微小晶体构成的微孔硅酸钙球形颗粒和硅酸铝纤维复合而成，其中大部分硅酸铝纤维首先形成柔软的纸型材料，微孔硅酸钙颗粒和其余硅酸铝纤维沉积其上，填充在硅酸铝纤维之间的大孔隙中。由于微孔硅酸钙颗粒被硅酸铝纤维分割，互相之间不能通过氢键直接相连，从而无法形成普通微孔硅酸钙材料所具有的刚性结构，只能借助硅酸铝纤维构成柔性结构。具有大量0．1～1μm直径孔隙的微孔硅酸钙颗粒极大程度地限制了材料内空气的对流传热，同时，实验发现减少大孔隙和适当增加材料的致密度可以降低辐射传热，从而进一步降低材料的导热系数。这种复合材料的表观密度为0．25～0．32g／cm^3，热面温度1000℃下的表观导热系数可低至O．08W／（m·K）。     

用于铸铝模具的中硅耐热铸铁的研制

某铝厂要求制备良好的耐热性及综合力学性能的模具，并尽量降低制造成本，为此进行了试验研究。试验通过添加一定量的Cr、Al、Cu等合金元素制备耐热球墨铸铁，并在此基础上不断调整碳硅含量，使其在一定范围内性价比达到最优。最终得到制备铸铝用模具的优良材料，其配比为（质量分数）：2．7％C，5．0％Si，0．7％Cr，0．6％Ca，0．5％Al。     

TiNb（Y_2O_3）长纤维增强Ti－48Al－2Cr－2Nb合金复合材料的弯曲变形与界面

研究了ＴｉＮｂ（Ｙ２Ｏ３）连续纤维增强Ｔｉ－４８Ａｌ－２Ｇｒ－２Ｎｂ合金复合材料的界面及显微组织。研究发现：复合材料的弯曲强度比基体略有提高，弹性模量和挠度有所下降。在纤维和基体之间形成一层约１０～２０μｍ厚的α２－Ｔｉ３Ａｌ性层，近界面基体组织有片层化倾向。大量变形层错带和孪晶出现及界面位错墙的形成成为塑变及强化的主要机制。     

Preparation of oriented linear copper fiber sintered felt and its performance

Long metal fibers were manufactured in horizontal lathe with a multi-tooth tool. Based on the coarse antler surface structure of copper fibers, a new sintering technology was put forward to manufacture a kind of oriented linear copper fiber sintered felt. The sintering mechanism of oriented linear copper fiber sintered felt was studied. Compared with sintered copper-wire felt, the characteristics of sintered copper-fiber felts were analyzed in details. Owing to the coarse antler surface structure of copper fibers, oriented linear copper-fiber felt was sintered under the condition ofmicro/nano scale range, and copper fibers easily bonded together in the sintering process. Microchannels with micro-scale coarse antler surface structure were constructed. These characters give oriented linear copper fiber felt some new merits： high filtration accuracy, high flow capability, low resistance loss, good capability to resistance pressure, stable and uniform pore, high specific surface area. The properties of oriented linear copper fiber sintered felt were analyzed.     

渗氮石墨炭源合成金刚石的实验研究

叙述了渗氮石墨炭源合成金刚石的效果，氮在金刚石晶体中存在的形式特征。讨论了石墨炭源中的氮含量、合成工艺等实验条件对金刚石合成及其晶体性质的影响，以及晶体中氮集合体（NS）形成机理。指出了进一步提高合成金刚石晶体质量的方法与途径。     

Effects of carbon content and solidification rate on thermal conductivity of grey cast iron

The thermal conductivity or diffusivity of pearlitic grey irons with various carbon contents is investigated by the laser flash method. The materials are cast in controlled thermal environments and produced in three dissimilar cooling rates. The cooling rate together with the carbon content largely influence the thermal conductivity of grey iron. Linear relationships exist between the thermal conductivity and the carbon content, the carbon equivalent and the fraction of former primary solidified austenite transformed into pearlite. The work shows that optimal thermal transport properties are obtained at medium cooling rates. Equations describing the thermal conductivity of pearlite,solidified as pre-eutectic austenite, and the eutectic of grey iron are derived. The thermal conductivity of pearlitic grey iron is modeled at both room temperature and elevated temperature with good accuracy.     

含硼石墨碳源合成金刚石的效果

叙述了含硼石墨碳源合成金刚石的效果。讨论了石墨碳源含硼种类及其掺量对金刚石合成效果及其晶体性能的影响。在对含硼石墨碳源多种性能进行测试与分析的基础上，指出了选择金刚石碳源材料的原则及必要性。     

化学镀制备玄武岩纤维/镍核壳结构及其表征

采用简单易行的化学镀方法，在较低的温度下制备出一种新型的玄武岩纤维／镍核壳结构。SEM、XRD、XPS分析结果表明，金属Ni颗粒吸附在玄武岩纤维表面，形成了一层均匀连续的镍壳层。通过对试验结果进行分析，得出了制备玄武岩纤维／镍核壳结构的最佳温度和pH值分别为50℃和10．0。文中对化学镀核壳结构的形成机理也进行了初步分析。