摘要
为改善镍磷复合化学镀层的性能,利用X射线荧光光谱、X射线衍射等分析方法研究了α-A l2O3在镀层中的含量对镀层硬度、耐磨性、孔隙率及镀层结构的影响。结果表明:镀液中α-A l2O3加入量小于1 g/L时,随镀液中α-A l2O3浓度的增大,镀层中α-A l2O3的含量提高,镀层硬度与耐磨性增大,孔隙率略有增加;当镀液中α-A l2O3含量为1 g/L时,镀层中α-A l2O3的含量达到最大值4.8%,镀态硬度达到750 HV,约为N i-P镀层的1.5倍,耐磨性约是N i-P镀层的5.0倍;镀态镀层为N i-P非晶与α-A l2O3晶体组成的复合镀层,经400℃热处理1 h后,镀层晶化为N i3P晶体、N i基固溶体,表面生成N iO晶体,镀层中α-A l2O3的结构不变。
Ni-P/α-Al2O3 composite coating was prepared using electroless plating. The influences of the content of α-Al2O3 on the micmhardness, wear resistance, porosity, and structure of the electroless Ni-P/a -AI2O3 composite coaling were investigated using X-ray fluorescence spectroscope and X-ray diffractometer. It was found that, as the contenl of a -Al2O3 in the plating hath was less than 1 g/L. the content of α-Al2O3 in Ni-P/α-Al2O3 composite coaling increased with increasing contenl of α-Al2O3 in the plating bath; the microhardness and wear resistance of the romposite coating increased in the same manner, and the porosity of the composile coaling increased slightly. When the content of α-Al2O3 in the plating bath was 1 g/L, the content of α-Al2O3 in the composite coaling reached the maximum of 4.86%, and the microhardness rose to 750 HV, about 1.5 times of that of the electroless Ni-P coating. At the same time, the wear resistance of the composite coating with 4.86% α-Al2O3 was also significantly increased as compared with (he electroless Ni-P coaling. Namely, the wear rate of the composite coaling with 4.86% α-Al2O3 was only about 20% of that of electroless Ni-P coating. Moreover, the as-deposited Ni-P/ α-Al2O3 composite coating was composed of amorphous Ni-P and α-Al2O3 crystal, while heat-treatment of the as-deposited composite coating al 400℃. for 1 h led to crystallization and formation of Ni3P2 NiO2 and nickel-matrix eutectic, with the structure of α-Al2O3 to be unchanged.
出处
《材料保护》
CAS
CSCD
北大核心
2007年第1期13-15,共3页
Materials Protection
