稻壳基陶瓷颗粒制备及其对铝基复合材料摩擦学特性的影响

发布时间：2018-10-25 08:20

【摘要】：本文以稻壳为原料,采用高温炭化法制备出稻壳基陶瓷颗粒(RHC)。利用化学镀方法制备出镀镍稻壳基陶瓷颗粒(Ni-RHC),研究实现RHC颗粒表面均匀化学镀镍的最优工艺;然后用镀镍颗粒制备成坯体,研究其摩擦学性能;并将镀镍颗粒作为铝基复合材料的增强体,研究其含量对复合材料摩擦学性能的影响。采用单因素和正交试验对RHC颗粒表面镀镍工艺进行优化,考察不同工艺参数对施镀效果的影响。结果表明:影响镀镍的因素顺序是:次亚磷酸钠浓度温度pH时间;RHC颗粒表面镀镍的优化工艺参数为:60℃、180 min、pH=11、次亚磷酸钠浓度为180 g/L。利用扫描电子显微镜,傅里叶红外光谱,X射线衍射等现代分析手段对颗粒表面与结构进行分析,结果表明:傅里叶红外光谱显示RHC有-OH、-CH_3、-CH_2-、-C_6H_5等官能团;X射线衍射图显示RHC中无定形碳居多,含有少量的石墨微晶,Ni-RHC中镍的X射线衍射特征峰表明施镀取得成功;SEM/EDS结果再次验证了RHC颗粒表面已成功镀上镍层,颗粒主要含有碳、硅、磷、镍和氧5种元素。利用冷压制成型技术将RHC和Ni-RHC颗粒制备成稻壳基陶瓷坯(RHA)和镀镍稻壳基陶瓷坯(Ni-RHA)摩擦材料;研究载荷和转速对其摩擦性能的影响。结果表明,同等条件下,Ni-RHA磨损体积相对于RHA降低100倍左右,在高载荷和速度条件下Ni-RHA减摩性能较RHA好。研究发现,在RHA对磨件钢球表面有一层黑色附着物,主要组成元素为C和O,对钢球表面碳进行拉曼分析。结果表明RHA对偶钢球表面碳发生了一定程度的石墨化。Ni-RHA由于在摩擦过程中镍首先剥落到摩擦界面形成连续的保护层,进而起到抗磨的功效。将制得RHC和Ni-RHC颗粒作为增强相,通过冷压烧结工艺得到RHC/Al和Ni-RHC/Al复合材料。研究不同颗粒添加量对复合材料的摩擦性能影响,结果表明当添加量为15 wt%时,磨损体积最小。复合材料的硬度测试结果表明,Ni-RHC/Al复合材料的硬度同比高于RHC/Al。进一步添加5 wt%MoS_2,该复合材料抗磨性能有了进一步的提升,这归因于MoS_2的抗磨减摩功效。磨损机理的研究结果表明,纯基体材料在摩擦过程中产生严重的塑性变形和粘着磨损。添加RHC硬质颗粒由于具有一定的承载能力,使得整体复合材料的抗磨性能得到有效的提升,但同时也容易导致摩擦过程中由于颗粒剥落产生磨粒磨损。添加Ni-RHC颗粒,摩擦作用首先使得颗粒表面金属镍剥落,从而有效改善了摩擦界面的进一步磨损。
[Abstract]:In this paper, using rice husk as raw material, rice husk based ceramic particle (RHC). Was prepared by high-temperature carbonization method. Ni-coated rice husk based ceramic particles (Ni-RHC) were prepared by electroless plating, and the optimal process of uniform electroless nickel plating on the surface of RHC particles was studied, and then the billet was prepared by nickel plating particles, and its tribological properties were studied. The effect of nickel-plated particles on the tribological properties of aluminum matrix composites was studied. Single factor and orthogonal test were used to optimize the nickel plating process on the surface of RHC particles, and the effect of different process parameters on the plating effect was investigated. The results show that the order of the factors influencing nickel plating is the concentration of sodium hypophosphite at pH time, the optimum technological parameters of nickel plating on the surface of RHC particles are as follows: 60 鈩，

本文编号：2293149