热处理对Fe-W-ZrO2纳米复合镀层结构和性能的影响

采用复合电沉积方法,在碳钢表面制备质量分数为Fe38.3%、W52.7%、ZrO29%的Fe-W-ZrO2纳米复合镀层,研究热处理对镀层结构和性能的影响。结果表明,镀态下Fe-W-ZrO2纳米复合镀层内部结构致密无裂纹,呈明显非晶态结构特征,具有较高的硬度和耐磨性;复合镀层经500℃热处理后开始晶化,随温度升高,镀层晶化析出α-Fe相,硬度、耐磨性继续提高;700℃时复合镀层晶化完成,M6C型复合碳化物Fe3W3C析出,与α-Fe相两相并存,镀层硬度、耐磨性急剧增大,到800℃时,Fe3W3C硬质相逐渐成为主相,硬度达到最高点1270HV,耐磨性是镀态下的5～7倍;而且纳米微粒ZrO2的引入不会在Fe-W非晶合金镀层中形成新相,在适当的热处理下能有效提高Fe-W-ZrO2纳米颗粒复合镀层的硬度、耐磨性。

Influence of heat-treatment on the structure and characteristics of Fe-W-ZrO2nano-composite coatings

New nano-composite layers of Fe-W-ZrO2 Fe 38.3%(w), W 52.7%(w), ZrO2 9%(w) were obtained on carbon steel by composite electrodeposition. The effects of the heat treatment on structure and characteristics of the coatings were studied. The results show that as-deposited composite films appear cracks free morphology with obvious amorphous characteristics and compact structure. The hardness and wear resistance are higher than those of Fe-W amorphous alloy. Fe-W-ZrO2 composite coatings begin to crystallize when heat treated at 500 ℃, crystal phases α-Fe are formed. With the increase of heating temperature, the crystal phases and the characteristics increase continuously. When the temperature reaches 700 ℃, M6C type compound carbide F3W3C appears with the α-Fe phases, the crystallization course finishes, Meanwhile, the characteristics rapidly increase. When the temperature reaches 800 ℃, F3W3C phase in the coatings increases and becomes the main phase. The hardness of the coatings reaches the peak 1 270HV, the wear resistance is 5-7 times the value of as-deposited. It is also proved that the addition of ZrO2 nano-particles does not cause the formation of new phases, and plays an important role in improving the characteristics of the composite coatings.