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1、南京航空航天大学硕士学位论文PTFE与无机颗粒填充聚甲醛摩擦磨损性能的研究姓名：陶克梅申请学位级别：硕士专业：材料加工工程指导教师：向定汉20070301南京航空航天大学硕士学位论文 i摘 要 聚甲醛（POM）是一种高结晶工程塑料，具有高的机械强度、良好的尺寸稳定性、耐蚀性、耐磨性以及抗疲劳性能，被广泛应用于汽车、电子与精密仪器等领域。然而纯 POM 的滑动摩擦系数较大，不宜用作滑动部件。迄今为止，降低 POM 的摩擦系数最有效的方法是添加聚四氟乙烯（PTFE）制备成POM-PTFE 复合材料。为了进一步改善 POM 的摩擦磨损性能，扩大其应用范围，以 PTFE 为润滑剂分别与石墨、玻璃纤维及
2、高岭土改性 POM，选择商用的POM-20%PTFE 作摩擦对比研究，希望获得更优异的性能。 本研究选择 PTFE-石墨、PTFE-GF 与 PTFE-kaolin 添加到 POM 中，通过单螺杆挤出后， 采用热模压法制备出不同配方的 POM-PTFE-石墨、 POM-PTFE-GF复合材料与 POM-PTFE-kaolin 复合材料。 利用广角 X-射线衍射对 POM 复合材料进行了分析，通过仪器自带的积分软件计算 POM 基体结晶峰与非结晶峰的面积，从而得到 POM 复合材料的结晶度。 将POM-PTFE-石墨与POM-PTFE-GF复合材料在两种不同载荷（6.2 Mpa和3.3 Mpa）
3、条件下，在往复式滑动摩擦实验机上进行实验，实验条件为：相对湿度为(603)%，往复频率为1.0 Hz，往复行程为14.0 mm。结果发现：在载荷为6.2 Mpa 条件下，POM+20%PTFE+10%GF复合材料的耐磨性为POM+20%PTFE复合材料的1.47倍；在载荷为3.3 Mpa条件下，POM+20%PTFE+5%石墨复合材料的摩擦系数比POM+20%PTFE复合材料降低了18%。 将POM-PTFE-kaolin复合材料也在往复式滑动摩擦实验机上进行实验， 结果表明：含高岭土的POM+20%PTFE+7.5%kaolin复合材料的摩擦系数和磨损率最低，与POM+20%PTFE复合材料
4、相比分别降低了10%和18%。 可见， PTFE 与无机颗粒能够协同降低 POM 的摩擦系数和磨损率。 关键词：关键词：聚甲醛（POM） ，聚四氟乙烯（PTFE） ，石墨，高岭土，复合材料，摩擦磨损 PTFE 与无机颗粒填充聚甲醛摩擦磨损性能的研究 iiAbstract Polyoxymethylene (POM) is a high-crystalline engineering plastic, which has high mechanical strength, good stability, corrosion resistance and wear resistance as we
5、ll as anti-fatigue properties. So POM is widely used in automobile, electrical appliance, precision apparatus, etc. However, pure POM against steel exhibits a high coefficient of friction, and which is not suitable for sliding components. So far, the most effective way to reduce coefficient of frict
6、ion of POM is to prepare the PTFE-POM composites filled with polytetrafluoroethylene (PTFE). In order to increase the applicability of the POM in the bearing industry, the graphite, glass fiber, kaolin and PTFE, which was acted as a solid lubrication, were selected for the modifying agents, then the
7、 POM composites were prepared. A commercial POM-20%PTFE composite was chosen to carry out a comparative investigation. It is expected to further improve the tribological properties of POM. The different contents of the PTFE-graphite, PTFE-GF and PTFE-kaolin, respectively, were added into POM, then t
8、hey were extruded with a single-screw extruder.The POM-PTFE-graphite, POM-PTFE-GF and POM-PTFE-kaolin composites were hot-molded into slab specimens. Wide angle x-ray diffraction (WAXD) patterns were taken on a Bruker D8 ADVANCE diffract-meter (Germany) with Cu-filtered Cu k radiation at room temper
9、ature. The crystalline area and the amorphous area were calculated with a software of this apparatus, then the mass fraction crystallinity of the POM composites were obtained. For the POM-PTFE-graphite and POM-PTFE-GF composites, the friction and wear tests were carried out in a reciprocating tribom
10、eter under two different loading conditions. These composites were tested against a 45 carbon steel track, at room temperature in ambient atmosphere (603)%RH. The conditions were a reciprocating frequency of 1.0 Hz. Results show that by comparison to a POM+20%PTFE composite, a POM+20%PTFE+5%graphite
11、 composite exhibited a relatively low coefficient of friction under loading conditions of 3.3 Mpa and a POM+20%PTFE+10%GF composite exhibited a relatively low specific wear rate 南京航空航天大学硕士学位论文 iiiunder loading conditions of 6.2 Mpa. For the POM-PTFE-kaolin composites, the friction and wear tests wer
12、e also carried out in a reciprocating tribometer. It is found that a POM+20% PTFE+7.5%kaolin composite exhibited a relatively low coefficient of friction and high wear resistance compared to a POM+20%PTFE composite. Key words: Polyoxymethylene (POM); Polytetrafluoroethylene (PTFE); Graphite; Kaolin;
13、 Composites; Friction and Wear 南京航空航天大学硕士学位论文 III图表清单 图清单 图 2.1 石墨的晶体结构 .11 图 2.2 POM 复合材料成型过程. 13 图 2.3 POM 复合材料挤出造粒工艺流程. 14 图 2.4 POM 复合材料模压成型工艺流程. 16 图 2.5 滑动摩擦磨损实验试件示意图 . 18 图 3.1 纯 POM (A) 的 XRD 图谱. 21 图 3.2 POM+20PTFE（B） （挤出）XRD 图谱. 22 图 3.3 POM+20PTFE（B） （高混）XRD 图谱. 22 图 3.4 POM+20PTFE+5石墨（D）的 XRD 图谱. 23 图 3.5 POM+20PTFE+10GF（F）的 XRD 图谱. 23 图 3.6 POM +5kaolin（G）的 XRD 图谱. 24 图 3.7 POM +7.5kaolin（H）的 XRD 图谱. 24 图 3.8 POM+20PTFE+5kaolin（J）的 XRD 图谱. 25 图 3.9 POM+20PTFE+7.5kaolin（K）的 XRD 图谱. 25 图 3.10 POM+20PTFE+10kaolin（L）的 XRD 图谱. 26 图 4.1 往复式滑动摩擦实验机与受
