鈷的添加對碳化鎢粒子強化銅基複合材料之耐磨耗腐蝕性的影響研究

Effect of Co Additive on the Wear Corrosion Resistance of WC Particulate-Reinforced Copper Matrix Composites

本研究係利用粉末燒結法，製作Cu、Cu-WC及Cu-WC-Co之銅金屬基複合材料，探討不同粒徑（1、3、6、9 µm）、不同含量（10、15、20 wt.%）之碳化鎢顆粒以及鈷的添加（1.5 µm、5wt.%）、對銅金屬基複合材料之耐磨耗性與在3.5% 氯化鈉（NaCl）水溶液中（pH 6.7）之耐腐蝕性及耐磨耗腐蝕性的影響。實驗結果顯示，於銅基材中添加碳化鎢可明顯提升其硬度，而且硬度隨碳化鎢之粒徑減小而增大，亦隨碳化鎢含量的增加而增大。於乾磨耗實驗中，碳化鎢的添加顯著地增加材料之耐磨耗性，而碳化鎢的粒徑較小，則具有較佳之耐磨耗性，並隨碳化鎢含量的增加，耐磨耗性也有明顯的提升，鈷的添加則可明顯增進抗磨耗性。銅基複合材料之耐腐蝕性及耐磨耗腐蝕性隨碳化鎢添加量的增加而變差，然而碳化鎢粒子較大時，銅-碳化鎢複合材料卻顯示較佳的耐蝕性及耐磨耗腐蝕性。鈷的添加使材料產生明顯的鈍化膜，因而增加了耐腐蝕性，並且可明顯地改善銅基複合材料之耐磨耗腐蝕性質。

Wear-corrosion behaviors of Cu-WC and Cu-WC-Co copper based matrix composites, formed by hot pressing, were tested on a block-on-ring test machine in 3.5wt NaCl aqueous solution(pH 6.7). The effects of both particle size and WC and Co contents on dry wear, corrosion, and corrosion-wear behaviors of the composites were investigated. The results indicated that both hardness and dry wear resistance of the composites increased with increasing WC content, and also increased with decreasing particle sizes. Co addition had a beneficial effect on the dry wear resistance. The corrosion and wear-corrosion resistance of Cu-WC composites decreased with increasing WC content. However, Co additive improved significantly both corrosion and wear-corrosion resistance of Cu-WC composites, which was strongly related to the increase of passivity.