聚酰亚胺摩擦学性能的研究

对热模压成型的聚酰亚胺(PI)试样在MHK-500型环-块摩擦试验机上测试了不同载荷P(N)、摩擦速度V(m·s-1)情况下,摩擦系数μ与摩擦持续时间t(min)的关系,并探讨了μ值随t,P,V变化的摩擦规律.结果表明V值增加,使第一阶段的μ峰值降低,峰值到来时间加快,峰宽变窄,第二阶段到来时间提前.而P值增加除了使μ峰值降低外,对第一、二阶段的其他参数的影响却相反.摩擦系数μ的表征值分别与P,V没有单值关系,而与单位面积所受的载荷P(MPa)和速度V的乘积pV值(MPa·m·s-1)具有指数关系.     

Tribological Property of Polyimide Porous Materials

Polyi mide(PI)is a kind of macromolecule mate-rial developed since the1950s,having superior physi-cal mechanical properties,resistance to hightempera-ture,resistance to acid and alkali,and excellent selflubricating property.Hence,it is widely applied inhigh and new-technology fields,such as the militaryindustry,electronic industry and aerospace indus-try[1].However,in the current research on the fric-tion performance of PI materials,the most concernedtopic is PI fil m materials,and it is sel…     

石墨对聚四氟乙烯（PTFE）抗静电性能的影响

采用冷压成型、热压烧结工艺制备石墨改性聚四氟乙烯（PTFE）复合材料,利用MS—T3000摩擦磨损试验仪和EST102A振动电容式静电计检测摩擦过程中产生的静电电压,并研究了石墨粒径、添加量对PTFE复合材料抗静电性能的影响。试验结果表明,添加石墨可以改善PTFE复合材料的抗静电性能,且添加小粒径石墨（4μm）的效果要明显优于添加大粒径石墨（30μm）的效果,当石墨含量（4μm）为5％时,抗静电性能最优,摩擦过程的静电电压接近于0V。     

脉冲铜沉积层织构及形貌的研究

采用脉冲电沉积工艺制备了铜沉积层,研究了电流密度、脉冲频率和占空比对铜镀层织构的影响。利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析了铜镀层的织构和形貌。实验结果表明,低电流密度下为(200)晶面择优取向,高电流密度下为(111)晶面择优取向,频率越高则择优取向越强。低频脉冲下制备的沉积层平整致密。     

成品油管线杂散电流调查及排除

通过测量管道对地电位、电位梯度和杂散电流方向,对成品油管线上的杂散电流进行了全面调查.结果表明,杂散电流干扰程度已经超过了标准规定的必须采取排流措施的警戒指标.为此,采取了牺牲阳极接地式排流,排流效率高于99%,并使管道达到了阴极保护     

超声波对聚氨酯泡沫塑料化学镀铜的影响

为了研究超声波对泡沫塑料化学镀铜的影响,比较了聚氨酯泡沫塑料在以Sn-Pd活化后直接加超声波进行化学镀铜以及在形成连续铜层的基础上施加超声波进行化学镀铜的效果.结果表明:直接在连续铜层上施加超声波不但可缩短镀铜诱导期,而且使镀速加快、施镀深度加大,并随超声波功率增加,铜层增重加快变缓.而在聚氨酯上未形成连续铜层前,在预处理以PdCl2敏化的基础上施加超声波,早期可将钯核震掉影响镀速,从而确定了施加超声波的时间至少在预镀5min后进行.     

孔密度和孔隙率对泡沫铜换热性能的影响

采用超声波辅助电沉积工艺制备了9种不同孔结构的泡沫铜,研究了水工质、层流-紊流转捩状态下(0.4~1.3 m/s)泡沫铜的孔密度和孔隙率对换热性能的影响。结果表明:相同孔隙率,孔密度从10 ppi增大到45 ppi时,泡沫铜的黏性系数K1和惯性系数K2分别降低约80%和50%,努赛尔数Nu提高了约1.0倍;相同孔密度,孔隙率从96%降低到90%时,泡沫铜的K1和K2分别降低约30%和20%,Nu提高了约0.5倍;10 ppi孔密度、96%孔隙率的泡沫铜具有最优的综合性能。     

Effects of Forming Pressure on the Porosity of Polyimide Porous Materials

Based on a series of experiments, the theory of relationship between normal pressure and pores＇ characters fit for polymer was set up for the first time. On the study of relation between normal pressure and porosity, experience model of polyimide porous materials was proposed which is similar to the traditional expe- rience model of the metal porous material. While being pressed, polyimide was found soon to come into elasto- plastic deformation progress in this paper, so the theory model of metal porous material based on Hooker＇s law was not fit for the polymer any more. A new elasto-plastic deformation and exhausting model is proposed which shows better agreement with polymer material＇s pressing process.