Ni-P-WC化学复合镀层的制备及性能研究
发布时间：2018-07-24 10:51
【摘要】：复合化学镀是一种新兴的表面处理技术,将它与热处理、激光处理等技术相结合,形成性能优异的耐磨性镀层已成为人们研究的焦点。本论文采用中性镀液经预镀+复合镀在45钢基体表面制备出孔隙率小、镀层结合力良好、厚度为20μm左右、含磷量为5.99%的中低磷非晶Ni-P-WC复合镀层;研究镀液中WC的添加量对镀速、镀层形貌及硬度等性能的影响,确定复合镀的最佳工艺参数;采用光学显微镜、原子力显微镜、扫描电镜、能谱仪和X射线衍射等手段对镀层表面形貌、成分及相进行分析。结果表明,随着镀液中WC含量增大,沉积速度逐渐下降,镀层表面逐渐变暗变黑,其外观质量变差;镀层起伏由0~2.1μm增加到0~3.7μm,粗糙度增大;镀层硬度随着镀液中WC含量的增多出现先上升后下降的趋势,当WC含量为3g/l时,镀层硬度达到最大。对复合镀层进行200℃、300℃、400℃、500℃热处理,发现,镀层由非晶态向晶态转变,并脱溶析出金属间化合物Ni3P,WC晶粒并未发生变化,镀层硬度提高,且在400℃热处理后硬度达到最高。对镀层采用两种激光器进行处理,发现,镀层分别在450V~750V电压下经纳秒激光器处理,其镀层形貌随着电压增大逐渐呈现出熔融的状态,但整体依然保持胞状形态;镀层硬度随着激光处理电压增大出现先升高后降低的现象,并在电压为550V时镀层硬度达到最高,XRD显示镀层依然保持非晶态;经光纤激光器处理后的镀层表面形貌明显改变,镀层表面出现显微微裂纹,且呈现出一种熔融状态,硬度下降明显,与纯镍相硬度相当,XRD表明镀层有晶态Ni析出。摩擦磨损实验结果发现,经纳秒激光器激光熔覆后的镀层摩擦系数最小,耐磨性最好。对镍磷微粒复合镀的生长机制进行探讨,认为在其在含有WC的地方优先生长,镍磷胞互相堆叠,逐层生长。
[Abstract]:Composite electroless plating is a new technology of surface treatment. Combining it with heat treatment, laser treatment and other technologies, it has become the focus of research on the formation of excellent wear-resistant coatings. In this paper, low and medium phosphorus amorphous Ni-P-WC composite coatings with low porosity, good adhesion, thickness of about 20 渭 m and phosphorus content of 5.99% were prepared on the surface of 45 steel substrate by pre-plating composite plating with neutral plating bath. The optimum technological parameters of composite plating were determined by the influence of the morphology and hardness of the coating, and the surface morphology, composition and phase of the coating were analyzed by means of optical microscope, atomic force microscope, scanning electron microscope, energy spectrometer and X-ray diffraction. The results show that with the increase of WC content in the bath, the deposition rate decreases, the coating surface darkens and the appearance quality becomes worse, the undulation of the coating increases from 0 ~ 2.1 渭 m to 0 ~ 3. 7 渭 m, and the roughness increases. With the increase of WC content in the bath, the hardness of the coating increased first and then decreased. When the WC content was 3g/l, the hardness of the coating reached the maximum. The composite coating was heat-treated at 200 鈩，
本文编号：2141139
[Abstract]:Composite electroless plating is a new technology of surface treatment. Combining it with heat treatment, laser treatment and other technologies, it has become the focus of research on the formation of excellent wear-resistant coatings. In this paper, low and medium phosphorus amorphous Ni-P-WC composite coatings with low porosity, good adhesion, thickness of about 20 渭 m and phosphorus content of 5.99% were prepared on the surface of 45 steel substrate by pre-plating composite plating with neutral plating bath. The optimum technological parameters of composite plating were determined by the influence of the morphology and hardness of the coating, and the surface morphology, composition and phase of the coating were analyzed by means of optical microscope, atomic force microscope, scanning electron microscope, energy spectrometer and X-ray diffraction. The results show that with the increase of WC content in the bath, the deposition rate decreases, the coating surface darkens and the appearance quality becomes worse, the undulation of the coating increases from 0 ~ 2.1 渭 m to 0 ~ 3. 7 渭 m, and the roughness increases. With the increase of WC content in the bath, the hardness of the coating increased first and then decreased. When the WC content was 3g/l, the hardness of the coating reached the maximum. The composite coating was heat-treated at 200 鈩，
本文编号：2141139
本文链接：https://www.wllwen.com/kejilunwen/jinshugongy/2141139.html
教材专著
