Al-Li P/M materials with dispersion of ceramic or intermetallic compound particles

陶瓷或金属间化合物颗粒分散的铝锂粉末冶金材料

基本信息

批准号：
62550529
负责人：
KANEKO Junichi
金额：
$ 1.22万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

Dispersion of ceramic particles has been studied in Al-Li alloys by applying mechanical alloying process which enables to produce alloys that are difficult or impossible to obtain by conventional melting and casting techniques. The matrix alloys used were Al-2.5Li and Al-2.5Li-1.2Cu-0.7Mg, and ceramic particles of AL_2O3, TiC and A6_4C_3 were added by the amount of 2 or 6 vo1%. P/M materials were produced from mechanically alloyed powders by cold pressing and hot extrusion. processing was all done in an argon atmoshpere so as to minimize oxidation loss of active Lithium. Metallography, tensile testing and age-hardening behavior were examined on obtained P/M materials.Fine and uniform dispersion of ceramic particles in the matrix of Al-Li alloys was attained by mechanical alloying. Obtained P/M materials showed high hardness due to despersion strengthening. However, age hardening was remarkably suppressed probably due to increased heterogeneous precipitation sites such as dislocation, subboundary and interphase boundary. This is not peculiar to P/M materials containing Li, since the same behavior was observed in Al-Cu and Al-CuMg P/M materials processed from mechanically alloyed powder. Nonetheless, these P/M materials showed high strength due to fine dispersion of ceramic particles. Al-Li-Cu-Mg P/M alloy with dispersion of 2 vo1% TiC or AL_2O_3 showed tensile strength as high as 600 MPa in as extruded condition. Further increase of ceramic addition caused decrease of elongation and thus tensile strength. These brittle P/M materials behave more like ceramics rather than metals, since they showed lower tensile strength than the converted values from their hardness. Specific elastic modulus was as high as 30 GPa and specific strength as high as 225 MPa, much higher than those of 7075-T6.

通过应用机械合金化工艺，研究了陶瓷颗粒在铝锂合金中的分散，这使得能够生产通过传统熔炼和铸造技术难以或不可能获得的合金。所用基体合金为Al-2.5Li和Al-2.5Li-1.2Cu-0.7Mg,并添加2或6 vo1%的AL_2O3、TiC和A6_4C_3陶瓷颗粒。 P/M 材料由机械合金粉末通过冷压和热挤压生产。加工过程全部在氩气气氛中进行，以尽量减少活性锂的氧化损失。对所获得的粉末冶金材料进行金相、拉伸试验和时效硬化行为研究。通过机械合金化，使陶瓷颗粒在铝锂合金基体中均匀分散。由于弥散强化，获得的 P/M 材料表现出高硬度。然而，时效硬化被显着抑制，可能是由于位错、亚晶界和相间晶界等不均匀析出位点的增加。这并不是含锂 P/M 材料所特有的，因为在由机械合金粉末加工而成的 Al-Cu 和 Al-CuMg P/M 材料中也观察到了相同的行为。尽管如此，由于陶瓷颗粒的精细分散，这些 P/M 材料表现出高强度。分散有2 vo1% TiC或AL_2O_3的Al-Li-Cu-Mg P/M合金在挤压状态下的拉伸强度高达600 MPa。陶瓷添加量的进一步增加导致伸长率下降，从而导致拉伸强度下降。这些脆性 P/M 材料的行为更像陶瓷而不是金属，因为它们的拉伸强度低于硬度换算值。比弹性模量高达30 GPa，比强度高达225 MPa，远高于7075-T6。