核壳型硼酸钙／SiO2复合微球的制备及摩擦学性能研究

Synthesis and Tribological Properties of Core-shell Calcium Borate/SiO_2 Composites

以硼砂、硝酸钙和正硅酸乙酯为原料,在温和条件下制备核壳型硼酸钙/Si O2复合微粒。利用透射电镜(TEM)、X射线衍射(XRD)和红外光谱(FT-IR)研究复合微球的结构,发现Si O2包覆于硼酸钙的表面。将油酸修饰的复合微粒分散于液体石蜡中,利用四球摩擦试验机在载荷392 N、转速1 450 r/min、时间30 min的条件下考察其摩擦学性能。结果表明,该复合微粒具有良好的摩擦学性能,其中质量分数1.0%的复合微粒可使液体石蜡的磨斑直径从0.7 mm降低到0.5 mm,摩擦因数从0.09降低到0.05。含硼酸钙/Si O2复合微粒的液体石蜡润滑时,磨痕表面生成含B、Fe和Si的摩擦膜,从而起到减摩抗磨的作用。

Core-shell calcium borates/SiO2 composites were synthesized by a facile way, using borax, calcium nitrate and tetraethoxysilane （TEOS） as row materials. The structure and morphologies of calcium borate were investigated by TEM, XRD and FT-IR, finding that SiO2 shell was covered on the calcium borates. The oil acid （OA） modified compos- ites were mixed into liquid paraffin and the tribological properties of the oleic acid modified calcium carbonates were evaluated on four-ball tester at 392 N load, 1 450 r/rain for 30 min. The results show that the composites possess excellent tri- bological properties. The wear scare diameter is decreased from 0. 7 mm to 0. 5 mm and the friction coefficient is dropped from 0. 09 to 0. 05 as 1.0% composites are added into base oil. The wonderful friction reducing and anti-wear properties of calcium borates/SiO2 composites are attributed to the formation of tribological film containing B, Fe and Si on the worn surface.