高速压制法制备Al_2O_3弥散强化铜合金

Al_2O_3 dispersion strengthened copper alloy prepared by high-velocity compaction

采用高速压制(HVC)方法成形Al2O3质量含量分别为0.34%、1.00%和3.19%的3种弥散铜合金粉末,研究不同粉末HVC的成形效果和压坯的烧结性能。结果表明:压坯致密度随冲击能量的增加而增加,随Al2O3含量的增加有所降低。在最大冲击能量为927.5 J时,3种粉末压坯的最大致密度分别达到98.4%、96.2%和93.4%。压坯在氢气中经1080℃烧结1 h后,致密度并无明显变化,但导电率显著提高,同时硬度略有降低。所制备的3种Al2O3弥散强化铜合金的导电率分别为81.0%(IACS)、64.1%(IACS)和48.3%(IACS),硬度分别为77.3、85.7和81.3 HRB。3种烧结合金在氢气中经1080℃处理2 h后,其硬度基本保持不变。整体而言,采用HVC法制备含0.34%Al2O3的弥散铜合金具有良好的导电率、硬度和抗高温软化性能,可基本满足点焊电极的实际应用需求。

The high-velocity compaction(HVC) was applied to press three kinds of dispersion copper alloy powders with Al2O3 mass fraction of 0.34%, 1.00% and 3.19%, respectively. The forming effects of powders and the following sintered properties were studied. The results show that the relative density of green compact increases with increasing the impact energy, and decreases with increasing the Al2O3 content. When the largest impact energy is 927.5 J, the maximum relative densities of compacts of the three powders reaches 98.4%,96.2% and 93.4%, respectively. After being sintered at 1080 ℃ in hydrogen for 1 h, the relative density of compacts has no obvious change, the electrical conductivity is significantly improved and the hardness slightly decreases. The electrical conductivity and hardness of the prepared three Al2O3 dispersion strengthened copper alloys are 81.0%(IACS), 64.1%(IACS) and 48.3%(IACS), and 77.3, 85.7 and 81.3 HRB, respectively. After being heat-treated in hydrogen at 1080 ℃for 2 h, the hardness of three sintered alloys is almost unchanged. In general, the dispersion strengthened copper alloy with 0.34% Al2O3 prepared by HVC has good comprehensive performances and its electrical conductivity, hardness and softening resistance at high temperature can meet the basic requirement of the practical application used as spot welding electrodes.