静电粉末喷涂法制备不同熔融指数聚醚醚酮涂层的机械和摩擦学性能

Mechanical and Tribological Properties of PEEK Coatings with Different Melt Indexes Prepared by Electrostatic Powder Spray Technique

通过静电粉末喷涂法在不锈钢基材上制备了不同熔融指数的聚醚醚酮(PEEK)涂层.熔融涂层在冰水混合物中淬火得到无定形涂层,将无定形涂层在260℃退火处理30 min得到半结晶涂层.X射线衍射(XRD)测试结果表明,退火处理使不同熔融指数的PEEK涂层从开始的无定形结构转变成为半结晶结构.PEEK涂层的硬度和摩擦学性能研究结果表明,在相同条件下结晶处理,PEEK熔融指数越大,结晶度越高.与无定形涂层相比,不同熔融指数PEEK的半结晶涂层的硬度更高,摩擦系数和磨损率更低.熔融指数较大的PEEK-B和PEEK-C均能形成平整的涂层,摩擦系数和磨损率稳定,熔融指数对其影响不大.半结晶涂层B和C的摩擦系数低至0.15以下,磨损率低至20×10-6mm3/(N·m)以下,更适合静电喷涂制备PEEK涂层.

Poly-ether-ether-ketone （ PEEK ） coatings with different melt indexes （ MI ） were prepared on the stainless steel substrate via electrostatic powder spraying method. Amorphous coatings were obtained by quenching the as-melted coatings into the ice-water medium. Semi-crystalline coatings were obtained by an-nealing the amorphous coatings in an oven for 30 min at 260 ℃. The XRD results indicates that the structure of PEEK coatings transforms from amorphous to semi-crystalline via the treatment of annealing. The hardness and the behavior friction of the PEEK coatings were tested. The result demonstrates that by the same treat-ment, the PEEK coatings with larger MI have higher crystallinity. The semi-crystalline PEEK coatings have higher hardness, lower friction coefficient and better wear rate than the amorphous ones. The poor fluidity of PEEK-A with lower MI leads to the rough coatings. Both of the PEEK-B and PEEK-C with larger MI can form smooth coatings and the friction coefficients and wear rates of them are stable. The friction coefficients of semi-crystalline coatings B and C are less than 0. 15, and the wear rates are less than 20＆#215;10-6 mm3/（N＆#183;m）. Therefore PEEK with larger MI is more suitable for the preparation of PEEK coating by electrostatic spraying.