TiN，AlN／Al2O3复合陶瓷材料的研究

综述了TiN／Al2O3，AlN／Al2O3以及（TiN，AlN）／Al2O3复合材料的研究现状。并指出颗粒增韧是复相陶瓷材料增韧最简单的方式之一，其中纳米复合、纳微米复合、多相复合是实现颗粒增韧的有效途径。在复相陶瓷的制备中，原位反应烧结是很有希望的技术，可以直接在基体中生成弥散分布的超细第二相颗粒，而使复合材料的性能大幅度提高。     

Processing and microstructure of investment casting turbine blade NITAC in-situ composites

Directional solidification was used to produce turbine blades by the Bridgman method. NITAC alloys with various carbon contents were investigated; the optimum range was found to be 0.40 to 0.48%. Within this range, except for the blade locking piece edges, the blade structure consisted predominantly of aligned eutectics. The in- situ eutectics were aligned tantalum fibers embedded in a γ- phase matrix. The blades were produced using an alloy displacement rate of 1.86 x 10 ^{- 6} m/s. Measurements of fiber spacings along the blade height indicated that the rate of displacement of the solidification front exhibited some variations. These variations were closely associated with dimensional changes in the turbine blade cross sections.     

Oxidation behavior of 2.25Cr-1Mo steel with prior tempering at different temperatures

The oxidation behavior of a normalized 2.25Cr-1Mo steel tempered previously for 10 hr at different temperatures between 873 and 1023 K has been studied up to a maximum duration of 1000 hr in air at 773–973 K. The oxidation resistance of the steel was found to decrease significantly with the temperature of tempering. Tempering of this steel is reported to cause microstructural changes involving precipitation of Cr as carbides and a decrease in the effective (free) Cr contents, that could influence the oxidation resistance of the Cr-containing alloys. Relative compositions across the thickness of the oxide scales, as analyzed by SEM/EDX and SIMS, suggest that a less Cr-rich (and less protective) and thicker scale on the steel formed because previous tempering caused extensive depletion of free Cr.     

REACTIVE DIFFUSION BETWEEN Si AND NbC AT 1300℃

ＲＥＡＣＴＩＶＥＤＩＦＦＵＳＩＯＮＢＥＴＷＥＥＮＳｉＡＮＤＮｂＣＡＴ１３００℃Ｃ．Ｒ．Ｋａｏ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｃａｌＥｎｇｉｎｅｅｒｉｎｇＮａｔｉｏｎａｌＣｅｎｔｒａｌＵｎｉｖｅｒｓｉｔｙＣｈｕｎｇＬｉ，Ｔａｉｗａｎ）Ｊ．Ｗｏｏｄｆ...     

高铬铸铁筛板研究

对高铬铸铁合金化和热处理工艺的研究结果表明，选用Ｃｒ／Ｃ比为７左右的Ｃｒ２０型高铬铸铁，在添加适量的Ｍｏ、Ｃｕ、Ｍｎ，并经合适的热处理后，可获得在马氏体基体上分布着较为均匀的Ｍ７Ｃ３型碳化物，使材料达到良好的强韧性配合，耐磨性明显提高，使用寿命明显高于原用筛板，达到与进口筛板相当的寿命，具有明显的经济效益。     

原位钛合金化铝合金摩托车车轮的微观组织和力学性能

研究了变质处理和未变质处理原位钛合金化摩托车车轮的微观组织和力学性能，并与传统A356合金制造的车轮的微观组织和力学性能进行了对比．发现原位钛合金化A356合金车轮的组织均较传统A356合金的细小、不管是否经过变质处理，三种车轮的硅颗粒均得到明显的纤维化，但未变质处理的A356合金车轮的硅颗粒稍粗。利用未变质A356合金制造的车轮力学性能稍低于传统A356合金的，而经变质处理后，车轮的强度与传统车轮的相当，但塑性明显高于传统A356合金车轮的。     

原位合成TiB_2/ZL109复合材料的力学性能

通过原位合成法成功制备了亚微米级TiB_2颗粒增强ZL109复合材料,测量了不同颗粒含量复合材料的弹性模量和25～400℃的抗拉强度(UTS)。结果表明,复合材料的弹性模量随颗粒含量提高而提高,颗粒含量15%(质量分数,下同)时,复合材料的弹性模量比基体合金提高了32%；抗拉强度也明显高于基体合金,10%TiB_2 /ZL109复合材料在260℃时的强度比基体合金提高了105MPa。     

Influence of Tempering Temperature on Cyclic Viscoplastic Behaviour of 55NiCrMoV7 Steel

Low cycle fatigue behaviour of a steel 55NiCrMoV7 under tour tempered conditions is reported. One special type of total swain controlled isothermal cyclic deformation tests were performed in the temperature range 20℃ to 600℃ for the steel tempered 2h at 350℃, 460℃, 560℃ and 600℃. The influence of temperature on cyclic behaviour was investigated. Generally, the cyclic stress response shows an initial exponential softening for the first few cycles, followed by a gradual softening without cyclic softening saturatioo. At 10^-2 strain rate, σmax.Δσ／2 decrease with the test tumperature for all hardness levels. They decrease linearly with tempering temperature when testing temperature is lower than that of tempering, but rest nearly constant when test temperature is equal to or exceed tempering temperature of steel. Cyclic softening intensity increases with testing temperature from 300℃ to 600℃, but the maximal softening intensity occurs at room tumpemture. The strain rate influences notably the cyclic behavioor when T≥50℃, The time dependence of cyclic behaviour is closely related to test temperature and the tempering history of the steel.     

原位TiC粒子增强Al－Si合金的组织及性能

采用新工艺方法──熔铸直接接触反应法制取原位ＴｉＣ粒子增强铸造Ａｌ基复合材料．该方法是将Ａｌ－５．６ｗｔ－％Ｓｉ合金升温至７５０℃，再把Ａｌ－４０ｗｔ－％Ｔｉ－１０ｗｔ－％Ｃ粉末压制块压入，使Ｔｉ和Ｃ在Ａｌ－Ｓｉ合金液中直接反应生成直径为０．１－１．０μｍＴｉＣ颗粒，并均匀地分布在α－Ａｌ基体中，晶界上无明显颗粒聚集，制成品性能优异．     

Cu-Cr原位复合材料组织性能研究

采用感应加热熔炼及通过热锻和线拉变形结合中间热处理制备了Cu-15％Cr原位复合材料，用SEM和TEM等技术对形变Cu—Cr原位复合材料的Cr纤维形成过程、立体形态进行了分析。结果表明，在变形过程中Cr树枝晶发生转动，平行于线轴方向排列；Cr纤维立体形态则为卷边的薄片状。测定了形变Cu—Cr原位复合材料的抗拉强度，分析表明，强度随变形量的增加而提高，与纤维相间距呈Hall—Patch关系。