粉末冶金法制备SiC_p/Al复合材料的研究现状

详细阐述了SiC_p/Al复合材料的粉末冶金制备工艺,包括混粉工艺(如球料比、球磨时间、球磨机转速),冷压成形(如压制压力、保压时间、静置时间等参数的选择),除气(如除气方法),热固结技术(如真空热压法、常压烧结热挤压法、粉末热挤压法)等;简述了增强体(SiC_p)尺寸、界面对SiC_p/Al复合材料性能的影响以及SiC_p/Al复合材料的强化机制;最后展望了SiC_p/Al复合材料的发展方向。     

热压法制造金刚石—硬质合金复合柱齿的研究

采用添加Ni-P活化烧结WC-Co硬质合金的特殊工艺,用热压法成功地烧结出了新型的金刚石-硬质合金复合柱齿。研究分析了热压烧结工艺(烧结温度、烧结压力和保温保压时间)对新型金刚石-硬质合金复合柱齿性能的影响。     

热压法制造金刚石—硬质合金复合柱齿的研究

采用添加Ni-P活化烧结WC -Co硬质合金的特殊工艺 ,用热压法成功地烧结出了新型的金刚石 -硬质合金复合柱齿。研究分析了热压烧结工艺 (烧结温度、烧结压力和保温保压时间 )对新型金刚石 -硬质合金复合柱齿性能的影响。     

根据我国镍资源特点选择优化羰基法精炼镍工艺

叙述了国外具有工业规模的羰基法精炼镍的典型工艺流程。评述了常压法、低压法、中压法及高压羰基法精炼镍工艺的优缺点。总结了国内近30年羰基法精炼镍工艺的研究成果,并根据钢铁研究总院多年对国内镍资源进行的羰基法精炼镍工艺流程的研究,提出了最适合我国镍资源特点的羰基法精炼镍工艺———中压羰基法精炼镍技术。     

高炉熔渣干式显热回收技术研究进展

高炉熔渣含有大量的热，将其回收利用具有极大的经济和社会效益。传统的水淬工艺对熔渣显热基本没有回收，干式显热回收技术得到国内外研究者越来越多的关注。为此，分析了熔渣显热回收的基本问题和技术难点；列举了已研究的各种干式显热回收典型工艺；介绍了旋转杯熔渣粒化技术、水蒸汽 甲烷重整渣热回收技术等最新研究进展，对不同回收工艺进行了综合评价；并展望了熔渣显热回收技术的发展前景。     

先进氧化物弥散强化钢制备技术研究进展

采用先进氧化物弥散强化(ODS)技术制备出的氧化物弥散强化钢具有优异的力学性能和耐蚀性能。对ODS钢铁材料的配粉技术、制备工艺、微观结构、力学性能和强化机制进行了阐述。ODS钢原料中高品质第二相粒子和金属粉体是制备基础，将纳米结构氧化物粒子添加到金属基体中，常采用球磨合金化法制备出金属粉末原料，其中Y₂O₃、Al₂O₃等纳米氧化物是ODS钢常用的弥散强化粒子。ODS钢铁材料的组织和性能取决于其制备工艺，传统冶炼铸造法制备ODS钢较困难，而粉末冶金法制备ODS钢较为常用，包括热挤压法、热等静压法、放电等离子烧结法等；增材制造工艺是制备ODS钢的新途径，特别是选区激光熔化法已经用于研制ODS不锈钢。Y₂O₃粒子ODS钢中，易与氧结合的金属元素(Ti、Al、Zr等)与固溶到基体中的Y和O元素发生反应后，以复杂氧化物形式析出并赋存于微观组织中。大量弥散分布的第二相粒子钉扎晶界和位错，阻碍位错运动，从而起到弥散强化效果，提高了先进ODS钢的力学性能和耐蚀性能，扩大了...     

马钢300m^2烧结机取消热筛工艺的研究与实践

简要阐述了马钢３００ｍ２烧结机取消热筛工艺的基本研究和工业性模拟试验研究；对马钢３００ｍ２烧结厂取消热筛工艺。在工厂设计中采取的技术保证措施及生产实践作了简要的介绍；并分析了取消热筛工艺能带来的经济效益和社会效益。     

MoSi_2材料的制备及其应用

MoSi2是一种重要的用于制造高温发热元件的材料和航空航天用高温结构材料。比较了MoSi2的几种制备方法:机械合金化、自蔓延高温合成、热等静压法、固态置换反应和原位反应自生复合技术等。结果表明:为实现MoSi2材料的产业化,应采用原位反应热压制备工艺。评述了MoSi2及其复合材料的工业应用情况,提出了其未来研究发展的方向。     

CONSTEEL电炉铁水热装工艺探讨

韶钢炼轧厂CONSTEEL电炉热装铁水工艺有效地降低了冶炼电耗和钢铁料消耗、缩短了冶炼时间；文章探讨热装铁水工艺的热装比例、供电曲线和造渣制度，以期进一步改善有关技术指标．     

纳米复相稀土永磁材料研究进展

综述了纳米复相稀土永磁材料的研究现状;详细介绍了纳米复相永磁体的制备方法及磁性能,在粘结磁体、快淬磁体和磁控溅射磁体的基础上,又详细介绍了制备大块致密磁体的方法:热压法和热挤压法.分析了各种制备方法的优缺点;论述了添加合金元素和热处理工艺对磁性能的影响.并对纳米复相稀土永磁材料的研究前景作了展望.     

Effect of Hot Pressing on Microstructure and Mechanical Properties of Bulk Nanocrystalline Fe3Al Materials Containing Manganese Element

 Bulk nanocrystalline Fe3Al materials containing manganese of 10% were prepared by aluminothermic reaction. Hot pressing of those materials was performed at different temperatures and times. The microstructures of the alloy were investigated by optical microscope (OM) and electron probe microanalyzer (EPMA). The grain sizes of the materials were analyzed by X-ray diffraction (XRD) and transmission electron microscope (TEM). The results showed that the grain sizes of the materials increase after hot pressing. The grain sizes of the materials decrease with increasing the hot pressing times at the same temperature and the grain sizes of the materials increase with increasing hot pressing temperatures at identical times. The hardness and compressibility of the materials were also tested. The results showed that the hardness decreases with increasing hot pressing times at 800 ℃ and hardness increases with increasing the hot pressing temperatures. The variation of hardness with grain size of the nanocrystalline Fe3Al materials after hot pressing is contrary to the Hall-Petch relation. The materials are not broken during hot pressing and exhibit good plasticity and compressibility.     

Thermomechanical properties of electric brush materials produced from Teflon-lead metallic polymer and graphite powders

Conclusions Metallic polymer powders have been obtained which can be employed, with various carbon component additions, as starting materials for the production, by hot pressing, of electric brushes. A study was made of the thermomechanical properties of various electric brush materials of this type. The best properties were found to be exhibited by lead + Teflon + graphite metallic polymers produced by simultaneous heat treatment and subsequent hot pressing at 150°C.Translated from Poroshkovaya Metallurgiya, No. 11(203), pp. 43–47, November, 1979.     

热压加工对含铬、镍块体纳米晶Fe_3Al组织和性能的影响研究

对通过铝热反应熔化制备的含10%(质量分数,下同)的铬和10%镍的块体纳米晶Fe3Al材料在不同温度、不同次数下进行了热压加工。利用XRD研究了热压加工前后纳米晶粒尺寸的变化,并测试了硬度变化和压缩率。结果显示:含10%铬的纳米晶Fe3Al在600℃表现出较好的塑性变形能力,材料在热压加工前后都是由无序bcc结构的Fe3Al相组成;含10%镍的纳米晶Fe3Al在800和1 000℃表现出较好的塑性变形能力,材料在热压加工前为无序bcc结构的Fe3Al相,在1 000℃热加工后,已转变为DO3有序结构;两种材料的压缩率都随着热压加工次数的增加逐渐增大。含10%铬的纳米晶Fe3Al在600℃和含10%镍的纳米晶Fe3Al在1 000℃随着热压加工次数的增加,晶粒尺寸都发生了增大,但材料硬度变化不大。     

Stability of hydroxyapatite while processing short-fibre reinforced hydroxyapatite ceramics

Reinforcement by short fibres has been adapted from modern ceramic processing technologies to achieve an improvement of structural properties of hydroxyapatite. However, the influence of the reinforcement fibres on the thermochemical behaviour of the hydroxyapatite has yet to be clarified comprehensively. Titanium, alumina and 316L-stainless steel, all materials with a proven record as implant materials, were chosen as reinforcement materials. Short fibres of these materials were incorporated in a matrix of hydroxyapatite to toughen the hydroxyapatite. Composites were processed by sintering in air, hot isostatic pressing and a method combining sintering in inert gas atmosphere and hot isostatic pressing.     

一种新型难熔金属异型件的制备技术及其应用

主要介绍了粉末高能喷涂成形技术及其在耐高温材质构件上的应用研究。采用真空热压和高压热等静压提高构件的致密度。结果表明:等离子喷涂成形纯钨喉衬的相对密度为85.6%;经真空热压处理后,喉衬相对密度提高到91.7%;经高压热等静压处理后,喉衬相对密度增大至96.7%。由此可见,高压热等静压可大大提高喷涂成形件的致密度。高能喷涂成形技术可制备出形状复杂的耐高温材质构件,如钨/钼复合喷管、钨坩埚?钨发热体、破甲弹药形罩等异形构件和二硅化钼回转体等。     

碳化硼的低温热压

研究了B₄C的热压工艺及Al₂O₃对热压B₄C烧结性能的影响。结果表明,采用1.0μm左右的B₄C粉,添加Al₂O₃作为烧结助剂,在1750℃、35MPa热压条件下可获得烧结致密体。而制造纯B₄C材料的热压温度需高于2100℃,才能使坯体致密。添加5%~30%Al₂O₃可明显降低B₄C材料的热压温度,但随Al₂O₃含量的增加,这种作用不很明显,反而使材料的硬度降低。当Al₂O₃含量为5%~10%(Wt)时,材料的硬度(HRA96.5)与纯B₄C热压材料的硬度(HRA97.0)接近。     

制备工艺对碳化硼陶瓷性能的影响

以活性炭和碳化硅为烧结助剂,采用真空热压工艺,制备了碳化硼陶瓷材料.研究了真空热压工艺、烧结助剂对碳化硼陶瓷性能及断口的影响,结果表明,以活性炭和碳化硅为烧结助剂的碳化硼陶瓷随热压压力增加,开口孔隙度减小,相对密度和抗弯强度增加.添加活性炭的碳化硼陶瓷在热压压力为35MPa下,开口孔隙度有最小值(1.7%),相对密度(91.7%)和抗弯强度(277.6MPa)达最大值;以碳化硅为烧结助剂的碳化硼陶瓷在热压压力为30MPa下,开口孔隙度有最小值(0.66%),相对密度(91.9%)和抗弯强度(173.6MPa)达最大值.添加活性炭的碳化硼陶瓷随保温时间由30min增加到90min,开口孔隙度逐渐减小而相对密度逐渐增加(90min时分别达到0.19%、99.6%),抗弯强度先增加后减小,在保温时间为60min时抗弯强度达到最大值(351.7MPa).在相同的真空热压工艺下,添加活性炭的碳化硼陶瓷与添加碳化硅的碳化硼陶瓷相比,其开口孔隙度低,抗弯强度高.初步探讨了真空热压工艺以及添加剂促进碳化硼陶瓷烧结的机理.     

The effects of hot pressing parameters on the strength of aluminum/stainless steel composites

Stainless steel fiber reinforced aluminum matrix composites have been fabricated by hot pressing under different conditions of temperature, pressure, and time. The variation in tensile strength of these composites has been studied in detail, and the hot pressing parameters have been optimized in order to fabricate composites having maximum strength at any fiber volume fraction. Microprobe analysis and Scanning Electron Microscopy of these composites have revealed interesting features of fiber/ matrix interface. These features have been found helpful in explaining the dependence of strength of the composites on hot pressing parameters.     

Densification kinetics of a porous material based on molybdenum disulfide in hot pressing

Conclusions The relation has been established between the relative density of hot-pressed materials based on molybdenum disulfide and temperature, time, and applied pressure. The process of densification of a mixture of molybdenum disulfide and molybdenum powders in hot pressing is described by a volume viscous-flow equation allowing for the nonlinear dependence of the rate of flow of the solid phase of the porous material on stress. The effective rate of creep of the solid phase in hot pressing (1400°C) is inversely proportional to the gas pressure in the closed pores. Reduced rates of steady-state creep have been calculated, and the exponent n indicative of linearity of flow of the solid phase forming the porous solid has been determined.Translated from Poroshkovaya Metallurgiya, No. 5(209), pp. 36–39, May, 1980.     

热压工艺因素对Al_2O_3－TiC复合陶瓷刀具材料性能的影响

简介了Ａｌ２Ｏ３复合陶瓷刀具的研制工艺，着重分析了热压工艺因素对Ａｌ２Ｏ３复合陶瓷材料性能的影响。