摘要:选用脉冲电镀法制备Ni-Mo-Al合金镀层,研究了不同pH值,AlCl3浓度,电流密度,频率,占空比,电镀时间及温度条件下对于Ni-Mo-Al镀层中Al含量的影响,获得了较佳工艺条件, 研究结果表明当pH值为8.2,溶液中AlCl3浓度为3g/L,电流密度为18.5A/dm2,频率为5000Hz,占空比为1/2,电镀的时间为20min,镀液温度为26℃时,Ni-Mo-Al合金镀层中Al含量最大,为2.04%。分别使用扫描电子显微镜(SEM)、电子能谱仪(EDX)、X射线衍射仪(XRD)、摩擦磨损仪及热膨胀仪(DIL)对所得镀层的表面形貌、成分、物相结构、耐磨性能、热膨胀性能进行表征。结果表明:与Ni-Mo合金镀层相比,Ni-Mo-Al镀层表面结瘤变小,且数量有明显减少,结瘤分布不均匀,表面较不平整。 Mo含量减少47.29%,Ni含量增加了16.73%,镀层形态为晶态结构,Ni-Mo-Al镀层衍射峰对应2θ角与Ni-Mo合金镀层衍射峰对应2θ角相比发生较小偏移。镀层的磨损量增加了21.53%,摩擦系数由0.816减小到了0.540,同时Ni-Mo-Al合金镀层具有较好的耐高温性能,镀层的工程热膨胀系数大小排序为:Tα(Ni-Mo-Al)(-5.594×10-5)>Tα(Ni-Mo)(-6.804×10-5)。23945
毕业论文关键词: 脉冲电沉积;Ni-Mo-Al合金镀层;耐高温性能
Study on the process of Mo-Ni-Al planting
Abstract:The preparation of Ni-Mo-Al alloy pulse electroplating, studied the influence of electroplanting conditions on the content of Al in the Ni-Mo-Al coating, and determine better process conditions. The results show that when the value of pH is 8.2, the concentration of AlCl3 is 3g/L, the current density is 18.5A/dm2, the frequency is 5000Hz, the duty cycle is 1/2, time of plating is 20min, the planting solution temperature is 26 ℃, the largest content of Al in Ni-Mo-Al alloy coating is 2.04%.By scanning electron microscope(SEM), electron spectroscopy(EDX),X ray diffraction(XRD),friction wear tester and thermal expansion instrument(DIL) on the coating surface morphology, composition, phase structure, wear resistance, thermal expansion properties was investigated, the results showed that: compared with Ni-Mo alloy coating, Ni-Mo-Al coating surface nodules of reunion coating become smaller ,and has decreased obviously, the surface is not smooth, Mo decreased 47.29%,Ni increased 16.73%, the morphology of Ni-Mo-Al coating is amorphous structure, compared with the 2θ of the diffraction peak in the Ni-Mo alloy coating, 2θ of Ni-Mo-Al diffraction peak has shifted in different degrees, the wear of Ni-Mo-Al coating increased by 21.53%, The friction coefficient is decreased from 0.816 to 0.540,while the Ni-Mo-Al coating has good high temperature performance, engineering thermal coating coefficient order range in 30-1300℃ expansion is:Tα(Ni-Mo-Al)(-5.594×10-5)>Tα(Ni-Mo)(-6.804×10-5)
Keywords: pulse plating; Ni-Mo-Al; coating; High temperature resistant performance.
目 录
1 引言 1
1.1 合金电镀的介绍 1
1.1.1 合金电镀 1
1.1.2 合金共沉积的条件 1
1.1.3 钼及镍钼合金 2
1.2 Ni-Mo合金镀工艺研究现状 2
1.3 热障涂层的介绍 3
1.4 粘结层对热障涂层的作用 4
1.5 Al在粘结层中的应用 4
1.6 工艺条件对电镀法制备合金镀层的影响 5
1.7 本课题研究内容 6
2 实验部分 7
2.1 实验材料及试剂 7
2.1.1 实验材料 7
2.1.2 实验试剂 7
2.2 实验设备与装置 7
2.2.1 实验设备 7
2.2.2 实验装置 8
2.3 工艺过程 8 电沉积Ni-Mo-Al镀层的研究+文献综述:http://www.751com.cn/huaxue/lunwen_17219.html