钨酸铅高温润滑特性的研究

Study on the High Temperature Lubricating Properties of the Lead Tungstate

作者在对PbWO_4进行化学反应热力学计算的基础上,利用高温栓-盘式摩擦试验机、差热、X-射线衍射与能谱等多种手段,又对PbWO_4的高温润滑特性及其有关的摩擦化学现象进行了考察,指出PbWO_4具有良好的高温热安定性和摩擦-温度特性,而于500℃以上加热后可以发生少量的正方晶形向斜方晶形的转变;在高温下PbWO_4可以与摩擦偶件中的Ni、Fe元素的氧化物发生化学反应生成少量的NiWO_4、FeWO_4及PbO_1.44,这有利于提高PbWO_4膜与底材的结合强度。

The high temperature lubricating properties of lead tungstate (PbWO4) and the relevant tribochemistry phenomena were studied with a high temperature pin-disc tester, differential thermal analysis, X-ray diffraction method and spectrometry in this paper. The results are as follows: a. The elemental valences of Pb,W and O have not been altered even PbWO4 storing at 700℃ for 2hours. It is indicated that PbWO4 possesses good thermal stability, but a small amount of square crystal is transformed into iris. b. The heat pretreatment from the room temperature to 700℃ can strengthen the adhesion between PbWO4 and substrate, and the adhesive amount of PbWO4 powder increases with temperature. c. After the friction test at above 600℃, a continuous, compact brown film with good anti-friction effect is formed on the rubbing trace, thus the PbWO4 is of the good high temperature lubricating property. d. Above 600℃ temperature,PbWO4 can react chemically with nickel and iron oxides to produce small amount of NiWO4, FeWO4 and PbO1.44, these are beneficial to the increase of the adhesive strength between PbWO4 and substrate.