炸药爆轰合成石墨包覆金属纳米颗粒及其摩擦学性能

Explosive detonation synthesis and tribological performance of graphite coated metal nanoparticles

摘要:

以铁/钴/镍硝酸盐为金属源，与无水乙醇、尿素、黑索今（RDX）混合制得复合炸药，采用爆轰的方式制备出石墨包覆金属铁、钴、镍(Fe@G，Co@G，Ni@G)纳米颗粒并利用XRD，TEM-EDX，XRF的方法对合成产物组成、形貌和显微结构进行分析；同时将石墨包覆金属纳米颗粒按照一定比例（0%、0.2wt%、0.4wt%、0.6wt%和0.8wt%）分别与基础油(SN150)配制成五种混合润滑油，并采用四球磨擦实验研究其摩擦学性能。结果表明爆轰所得产物为核壳结构，直径在10~50nm左右，核心为单质金属，包覆层主要由石墨构成，厚度大约在3~8nm左右；添加了石墨包覆金属颗粒的润滑油摩擦性能有明显变化，摩擦系数和磨痕直径随着石墨包覆金属的含量呈现先减小后增大的趋势；三种石墨包覆金属中，Ni@G作为润滑油添加剂的摩擦学性能最好。

Abstract:

Graphite coated metal (Fe@G, Co@G, Ni@G) nanoparticles were prepared by a detonation method using ethanol, urea, RDX and metal source of nitrate as the composite explosive. The composition, morphology and microstructure of detonation products were analyzed by means of X-ray diffraction (XRD), transmission electron microscopy (TEM)-energy dispersive spectro-scopy(EDX) and X-ray fluorescence (XRF). To clarify the tribological properties, the lubricating mixed oils (SN150 base oil) with five different content (0%, 0.2wt%, 0.4wt%, 0.6wt% and 0.8wt%) of graphite coated metal nanoparticles were prepared, and then the four-ball tests were carried out separately. The results indicated that the product of detonation is core-shell structure with a range of 10-50nm. The core is single metal and the shell is mainly composed of graphite about 3-8nm. From the four-ball tests, the friction coefficient and wear scar diameter decrease first and then increase with the addition of graphite coated metal nanoparticles and Ni@G show the best tribological properties as a lubricant additive of graphite coated metal.