中文摘要：

以添加有纳米TiN颗粒的氨基磺酸盐镀液为基础镀液,采用超声-脉冲电沉积的方法在45钢表面制备了纳米TiN/Ni复合镀层,分析了电流密度对其微观形貌、显微硬度以及表面TiN含量及分布的影响。结果表明：当电流密度在2～5A·dm^-2时,复合镀层结构致密且厚度均匀,其厚度随电流密度的增大而增加;随着电流密度的增大,复合镀层表面晶粒先细化后长大,显微硬度先提高后降低,当电流密度为4A·dm^-2时,镀层表面平整,表面和截面硬度均达到最大,分别为677,763HV;复合镀层表面TiN的含量随电流密度的增大先增加后减少,当电流密度为4A·dm^-2时,其含量最高且分散均匀。

英文摘要：

With the sulfamate bath containing TiN nanoparticles as the basic bath, the nano-TiN/Ni composite coatings were deposited on 45 steel surface by ultrasonic-pulse electrodeposition method. The effects of current densities on the morphology and microhardness of the composite coatings and on the TiN content and distribution at the surface were analyzed. The results show that when the current density changed between 2A·dm^-2 and 5 A·dm^-2, the microstruetures of the composite coatings were compact and the thicknesses were uniform, and the thickness increased with the increasing current density. With the increase of the current density, the surface grains in the composite coatings first refined then enlarged, and the microhardness first improved then decreased. When the current density was 4 A·dm^-2, the surface of the composite coating was plain and the surface and cross-section microhardness reached the largest value of 677 HV and 763 HV respectively. The TiN content in the surface of the composite coating first increased then decreased with the increase of the current density, and achieved the highest value and a relatively uniform distribution at the current density of 4 A·dm^-2.