纳米Al2O3 填充聚四氟乙烯摩擦磨损性能的研究

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PTFE 复合材料的摩擦系数比非填充PTFE 的略高,且填充PTFE 复合材料的摩擦系数随填料含量的增加而有所增大. 由于PTFE 复合材料是粘弹性聚合物, 在外力的作用下发生粘弹性变形, 其摩擦系数的变化服从L= K P n- 1 (K 为常数, P 为载荷, 2ö3 < n< 1) [5, 8 ]. 由此可以看出, PTFE 复合材料的摩擦系数随着载荷的增大而减小. 当载荷增大到一定值时, 由于摩擦表面温度升高, 材料的机械强度降低, 承载能力下降, 摩擦系数又会有所增大. 而A l2O 3 含量较高的填充PTFE 复合材料在较高载荷作用下, 填料A l2O 3颗粒可被拉拔脱离PTFE 基体, 从而加剧塑性变形,导致摩擦系数增大.

3　结论a. 　纳米A l2O 3 填料可提高PTFE 的耐磨性. 但纳米A l2O 3 填料加剧复合材料中PTFE 基体的塑性变形, 且A l2O 3 含量越高相应的塑性变形越严重. 在本文试验条件下, 当A l2O 3 的含量为10% 左右时, 填充PTFE 复合材料的耐磨性最佳.b. 　纳米A l2O 3 填充PTFE 复合材料的摩擦系数较PTFE 的摩擦系数大, 且随填料含量的增加,PTFE 复合材料的摩擦系数有所增大.参考文献:[ 1 ]　Tanaka K, Kawakam i S. Effect of various fillers on the fric-tion and wear of PTFE2based compo sites [ J ]. W ear, 1982,79: 221～ 234[ 2 ]　L u X C, W en S Z, Tong J , et al. W ettability, so il adhesion,abrasion and friction wear of PTFE ( + PPS ) + A l2O3compo sites[J ]. W ear, 1996, 193: 48～ 55[ 3 ]　宫德利, 薛群基, 王弘立. PTFE 复合材料磨损机理的研究[J ]. 固体润滑, 1989, 9 (2) : 88～ 94[ 4 ]　李同生, 孙守镁, 胡廷永, 等. 聚四氟乙烯磨损机理的探讨[J ]. 摩擦学学报, 1992, 12 (3) : 222～ 232[ 5 ]　张招柱, 薛群基, 刘维民, 等. 几种金属氧化物填充聚四氟乙烯复合材料在干摩擦条件下的摩擦磨损性能[ J ]. 摩擦学学报, 1997, 17 (1) : 45～ 52[ 6 ]　杨剑, 滕凤思. 纳米材料综述[J ]. 材料导报, 1997, 11 (2) : 6～ 10[ 7 ]　陈夕, 黄丽, 徐定宇. 纳米材料的进展及其在塑料中的应用[J ]. 国外塑料, 1995, 13 (3) : 5～ 12[ 8 ]　王承鹤. 塑料摩擦学[M ]. 北京: 机械工业出版社, 1994

Fr iction andWear Properties of Nanocrystall ineAl2O3 Filled-PTFE Compos itesHE Chun2x ia1, SH IL i2p ing1, SHEN Hu i2p ing2(1. A g ricu ltu ral E ng ineering Colleg e, N anj ing A g ricu ltu ral U niv ersity , N anj ing 210032, Ch ina;2. N anj ing F iberg lass R esearch and D esig n Institu te, N anj ing 210012, Ch ina)Abstract: The f rict ion and w ear p ropert ies of po lytet raf luo roethylene ( PTFE ) compo sites f illed w ithnanocrystalline A l2O 3w ere evaluated w ith anMM 2200 f rict ion and w ear tester. The wo rn su rfaces of PTFEcompo sites w ere exam ined by mean s of scann ing elect ron m icro scopy (SEM ). It has been found that theinco rpo rat ion of nanocrystalline A l2O 3 in to PTFE increases the w ear resistance of PTFE bu t wo rsen s thef rict ion2reduct ion perfo rmance to some ex ten t. The f rict ion coeff icien t of PTFE compo sites increasesw ith theincreasing of A l2O 3 con ten t. The best w ear2resistance of the compo site is reached at a mass f ract ion of A l2O 3abou t 10%. Mo reover, nanocrystalline A l2O 3 as the f iller in PTFE leads to enhanced p last ic defo rmat ion ofPTFE mat rix in the compo site, w h ich sub sequen t ly increases the f rict ion coeff icien t.Key words: nanocrystalline A l2O 3; PTFE; f rict ion and w ear behavio rs