Nano-sized dispersoids formed by solid state reactions in mechanically alloyed aluminum based materials

机械合金化铝基材料中固态反应形成的纳米分散体

基本信息

批准号：
08650853
负责人：
KANEKO Junichi
金额：
$ 1.47万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

Mechanically alloying was carried out for the Al-Fe and Al-Mn systems from three different starting materials : (1) powders from prealloyed ingots, (2) mixed powders of pure elements and (3) pure aluminum powder with addition of oxides of alloying elements. Mechanically alloyed powders were consolidated to the P/M materials by vacuum hot pressing and hot extrusion. Structures and mechanical properties were examined on the P/M materials. It has been shown that oxide addition is an effective way to obtain materials of superior mechanical performance since dispersion of Al_2O_3 and aluminide compounds is obtained in situ by the displacement reaction of oxygen during or after mechanical alloying treatment. Furthermore, mechanically alloyed materials were produced in the Al-Cr, Al-Hf, AL-Mo, Al-Ti, Al-W, Al-Zr systems by adding the oxide of alloying elements to aluminum powder. X-ray diffraction revealed that the added oxides were discomposed and Al_2O_3 and aluminide compounds were formed … More in these materials. These aluminum alloy systems are known to be difficult to prepare by the melting and casting method because of significant differences in the density and melting point between aluminum nd slloying elements. It has been confirmed that mechanical alloying with additon of the oxides of alloying elements is an effective alloying method for such alloy systems. Since formation of dispersoids in these materials occurs by solid state reactions, the amount and average size of dispersoids can be more easily controlled than in the liquid state reactions. Thus, oxide addition enables to obtain nano-sized dispersoids formed by solid state reactions in mechanically alloyed aluminum based materials. Hardness increases were observed in many of these materials with the progress of such solid state reactions when consolidated materials were heated at very high temperatures such as 773 or 873K.The highest hardness increase of HV75 was observed in Al-Mo system when its hot-extruded material was heated at 873K for 40ks. Most of the as-extruded materials of these alloy systems showed high tensile strength above 500MPa, and thus dispersoids formed by solid state displacement ractions of oxygen in mechanically alloyed materials are shown to be effective for strengthening aluminum based materials. Less

采用三种不同起始材料对 Al-Fe 和 Al-Mn 系进行机械合金化：(1) 预合金锭粉末，(2) 纯元素混合粉末，(3) 添加合金化氧化物的纯铝粉通过真空热压和热挤压将机械合金化的粉末固结到粉末冶金材料中，并对粉末冶金材料的结构和机械性能进行了检查，结果表明，添加氧化物是一种有效的方法。机械合金化处理期间或之后通过氧的置换反应原位获得Al_2O_3和铝化物的分散体，从而获得机械性能优异的材料。此外，在Al-Cr、Al-Hf、AL中产生机械合金化材料。 -Mo、Al-Ti、Al-W、Al-Zr系在铝粉中添加合金元素的氧化物，X射线衍射结果表明添加的氧化物发生分解，生成Al_2O_3和Al_2O_3。众所周知，这些铝合金系统很难通过熔化和铸造方法制备，因为铝和合金元素之间的密度和熔点存在显着差异。添加合金元素的氧化物是此类合金体系的有效合金化方法，因为这些材料中弥散体的形成是通过固态反应发生的，所以弥散体的数量和平均尺寸比在合金中更容易控制。因此，在机械合金化铝基材料中，添加氧化物能够获得通过固态反应形成的纳米尺寸分散体，当加热固结材料时，随着此类固态反应的进展，观察到许多材料的硬度增加。在非常高的温度下，例如773或873K。当其热挤压材料在873K下加热40ks时，在Al-Mo系统中观察到HV75的最高硬度增加。这些合金系统的挤压材料表现出高于 500MPa 的高拉伸强度，因此机械合金材料中氧的固态置换比例形成的弥散体对于强化铝基材料非常有效。