Self-propagating high-temperature synthesis of TiAl-SiC and TiAl-Al2O3 intermetallic composites
Self-propagating high-temperature synthesis of TiAl-SiC and TiAl-Al2O3 intermetallic composites
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TiAl-SiC和TiAl-Al2O3金属间复合材料的自蔓延高温合成
DOI：
10.1007/bf00721021
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
J. Rawers
中科院分区：
文献类型：
--
作者：
W. Wrzesinski;J. Rawers
自蔓延高温合成 (SHS) 对于陶瓷、金属间化合物和复合材料的形成具有重要意义 [1, 2]。此类材料可以完全由国内矿物制成，是战略和关键金属的潜在替代品。在 SHS 反应期间，强放热反应在外部热源（例如火炬或电弧）引发后通过元素粉末反应物的压实组合物传播。一旦开始，反应就会以燃烧波的形式继续穿过材料，直到反应物耗尽，形成近净形状的烧结形式。 SHS 技术的主要优点是处理时间更短，可以减少钢筋的劣化，并且无需传统材料制造中使用的高温炉。由于高温合成过程可以挥发污染物，因此可以获得纯度更高的产品[3, 4]。早期研究显示 SHS 工艺的可行性，通常生产出具有多孔、海绵状外观的材料；然而，最近的研究表明，可以使用 SHS 技术与热压相结合来制造高密度 TiC 产品（约 5% 孔隙率）[5, 6]。矿业局有兴趣开发金属间复合材料，不仅作为战略金属的替代品，而且在恶劣的采矿和选矿环境中实现更好的性能。添加 SiC 或 Al 2 O 3 的 TiAl 金属间复合材料可以提供比单独使用 TiAl 的材料具有改进的高温性能的材料。针对此类复合材料开发 SHS 工艺可以提供一种简单且廉价的材料加工方法。本研究使用等原子比例的钛和铝组合物形成化学计量金属间化合物 TiAl，并添加 0、2、5、10、25 和 50% 的碳化硅或 Al2O3。粉末成分由纯度为 99.9% 的元素钛（-100 目）、铝（-325 目）、SiC（7# m）和氧化铝（10# m）粉末配制而成。称重钛和铝粉末，并使用衬有氧化铝的球磨机和氧化铝研磨球在甲醇中球磨至少 4 小时。然后将研磨粉末与 SiC 或 Al2O3 混合并单轴压实至约 75% 的理论密度。将添加了氧化铝或碳化硅的钛和铝粉末样品压制成平均直径为 1.9 厘米的圆柱形压块
Self-propagating high-temperature synthesis (SHS) is of considerable interest for the formation of ceramics, intermetallics and composite materials [1, 2]. Such materials can be made entirely from domestically available minerals and are potential substitutes for strategic and critical metals. During an SHS reaction, a strongly exothermic reaction propagates through a compacted composition of elemental powder reactants following initiation from an external heat source, such as a torch or arc. Once started, reactions continue in the form of a combustion wave through the material until the reactants are depleted resulting in a near net shape sintered form. Principal advantages of the SHS technique are shorter processing times, possible reduction in reinforcement deterioration, and elimination of the need for the high-temperature furnaces used in conventional material fabrication. Since the hightemperature synthesis process can volatilize contaminants, a product with increased purity can be obtained [3, 4]. Early investigations that showed the feasibility of the SHS process generally produced materials that had a porous, sponge-like appearance; however, more recent studies have indicated that a highly dense TiC product (approximately 5% porosity) could be fabricated using SHS techniques in combination with hot pressing [5, 6].The Bureau of Mines is interested in developing intermetallic composites not only as substitutes for strategic metals, but to achieve better performance in hostile mining and mineral-processing environments. Intermetallic composites of TiA1 with SiC or A1203 additions may provide a material with improved hightemperature properties over those of TiA1 alone. Development of the SHS process for these types of composites could provide a method for processing materials in an easy and inexpensive manner. Compositions of titanium and aluminium in equal atomic proportions to form the stoichiometric intermetallic compound TiAl along with 0, 2, 5, 10, 25 and 50 tool% additions of silicon carbide or A1203 were used in this study. Compositions of powder were formulated from 99.9% purity elemental titanium (-100 mesh), aluminium (-325 mesh), SiC (7# m) and alumina (10# m) powders. Titanium and aluminium powders were weighed and ball-milled for a minimum of 4 h in methanol using an alumina-lined ball mill and alumina grinding balls. Ground powder was then blended with SiC or A1203 and compacted uniaxially to approximately 75% theoretical density. Samples of titanium and aluminium powders plus additions of alumina or silicon carbide were compacted into cylindrical compacts averaging 1.9 cm in diameter