高熵合金增强Cu基复合材料的研究

发布时间：2018-03-27 14:31

  本文选题：AlFeCrCoNi高熵合金　切入点：铜基复合材料　出处：《西安工业大学》2015年硕士论文

【摘要】：铜基复合材料广泛应用于航空、航天、军事及火箭发动机等领域,而高熵合金是最近发展起来的具有高强度、高硬度及耐高温稳定性能的一种新型合金。为了了解高熵合金/Cu复合材料的性能,本文采用电弧熔炼法和机械合金化法制备AlFeCrCoNi高熵合金强化相,采用粉末冶金法制备高熵合金/Cu复合材料。借助金相显微镜、扫描电镜、硬度测试以及压缩试验等,研究了高熵合金制粉工艺及烧结工艺对高熵合金/Cu复合材料组织与性能的影响,得出主要结论如下：球料比为10：1,转速为300r/min,真空氩气氛保护不锈钢球磨罐内,正庚烷作为过程控制剂,球磨18h后,形成BCC体系的AlFeCrCoNi高熵合金,其晶粒尺寸为58A。对其800℃退火1h、1.5h和2h后随炉冷却发现,退火保温时间对合金的晶体结构和物相没有影响。通过电弧熔炼法制备的AlFeCrCoNi高熵合金,晶格常数为a=b=c=2.877,熔点为1384.3℃,压缩屈服强度为1290MPa,压缩断裂强度为2310MPa,断口形貌为解理台阶和河流花样,断裂机理为解理断裂。800℃退火后形成了BCC1相、BCC2相和HCP相。随着AlFeCrCoNi高熵合金强化相含量的增加,Cu基复合材料的致密度降低,电导率降低,硬度增大,抗压强度先增大后减小。随着烧结温度、烧结压强的增加,Cu基复合材料的致密度、硬度、抗压强度均增加,但电导率却有所下降。用350r/min的速度球磨74h(转12min停6min)所制备的高熵合金通过细小粒度选择后作为强化相,强化相20%的复合材料冷压150KN保压6min,热压烧结在973K、100MPa时保温保压2h后,其综合性能最优。电弧熔炼法制备的AlFeCrCoNi高熵合金,线切割成薄片之后,球料比为40：1,转速为400 r/min,球磨20h时制备成1-5μm的细小颗粒。以其为强化相,制备Cu-20wt.%AlFeCrCoNi复合材料,在973K,100MPa烧结1h后水冷,其压缩屈服强度为310 MPa,与纯铜相比增加了1.38倍,同时压缩率达到了60%以上。
[Abstract]:Copper matrix composites are widely used in aviation, aerospace, military and rocket engines, and high-entropy alloys have recently been developed with high strength. In order to understand the properties of high entropy alloy / Cu composite, AlFeCrCoNi high entropy alloy strengthened phase was prepared by arc melting and mechanical alloying. High entropy alloy / Cu composites were prepared by powder metallurgy method. Metallographic microscope, scanning electron microscope, hardness test and compression test were used. The effect of high entropy alloy powder making process and sintering process on the microstructure and properties of high entropy alloy / Cu composite was studied. The main conclusions are as follows: the ratio of ball to material is 10: 1, the rotational speed is 300 r / min, and the vacuum argon atmosphere protects the stainless steel ball mill tank. AlFeCrCoNi high entropy alloy of BCC system was formed after 18h ball milling of n-heptane as process control agent, and its grain size was 58A. annealing at 800 鈩，

本文编号：1671921