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Production of Nonequilibrium Alloy Powders by Ultrasonic and High-Pressure Gas Atomization Method and their Properties

超声高压气体雾化法制备非平衡合金粉末及其性能

基本信息

批准号：
61490003
负责人：
INOUE Akihisa
金额：
$ 3.65万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1988
项目状态：
已结题

项目摘要

A new liquid quenching equipment by utilizing an ultrasonic and high-pressure gas atomization method was designed and constructed with the aim of developing a method which can produce effectively amorphous spherical powders. Many factors of producing amorphous powders in Fe- and Co-based alloy systems were investigated and the atomization condition of producing the amorphous powders was established. Subsequently, the consolidation of the amorphous powders was tried by press-sintering at elevated temperatures. As a result, it was clarified that the consolidation is difficult for the spherical powders and the mixing of flaky powders to the spherical powders is very effective for the formation of amorphous bulks. From this information, the atomization equipment was modified so as to produce flaky powders as well as spherical powders. In the modification, the rotator was set up at the position just below the gas atomization nozzle and small atomized liquid droplets were flattened by the rotator, resulting in the formation of flaky powders with a small thickness of 1 to 3 m. Furthermore, the heat of relaxation was much larger than that for the melt-spun ribbons, indicating the achievement of much higher cooling velocities by the two-stage quenching method. The increase of cooling velocity is probably due to the subsequent cooling of super-cooled liquid droplets produced by gas atomization. In addition, the two-stage quenching technique was found to bring about the glass formation in new alloy systems such as Fe-C binary alloys and a remarkable extension of glass formation range in glass-forming alloy systems. These features of the newly developed two-stage quenching technique consisting of ultrasonic and high-pressure gas atomization followed by impact flattening of the supercooled liquid droplets are concluded to be attractive enough to confirm further progress of the two-stage quenching technique and the resulting nonequilibrium alloy powders.

设计并建造了一种利用超声和高压气体雾化方法的新型液相淬火装置，旨在开发一种有效制备非晶球形粉末的方法。研究了铁基和钴基合金体系中制备非晶粉末的各种因素，确定了制备非晶粉末的雾化条件。随后，通过在升高的温度下加压烧结来尝试非晶粉末的固结。结果表明，球形粉末的固结是困难的，将超细粉末混合到球形粉末中对于形成无定形块状物是非常有效的。根据这一信息，对雾化设备进行了改进，以便生产球形粉末以及球形粉末。在该改进中，旋转器设置在气体雾化喷嘴正下方的位置处，并且小雾化液滴被旋转器压平，导致形成具有1至3 μ m的小厚度的超细粉末。此外，弛豫热远大于熔纺薄带，表明通过两阶段淬火方法实现了高得多的冷却速度。冷却速度的增加可能是由于气体雾化产生的过冷液滴的后续冷却。此外，两段淬火技术还能促进Fe-C二元合金等新合金系的非晶形成，并显著扩大非晶形成合金系的非晶形成范围。这些功能的新开发的两阶段淬火技术组成的超声波和高压气体雾化，然后由冲击压扁的过冷液滴的结论是有吸引力的，足以确认进一步的进展，两阶段淬火技术和由此产生的非平衡合金粉末。