Effect of reinforcement content on the adhesive wear behavior of Cu10Sn5Ni/Si3N4 composites produced by stir casting

The main objective of this paper was to fabricate Cu10Sn5Ni alloy and its composites reinforced with various contents of Si3N4 particles (5wt％,10wt％,and 15wt％) and to investigate their dry sliding wear behavior using a pin-on-disk tribometer.Microstructural examinations of the specimens revealed a uniform dispersion of Si3N4 particles in the copper matrix.Wear experiments were performed for all combinations of parameters,such as load (10,20,and 30 N),sliding distance (500,1000,and 1500 m),and sliding velocity (1,2,and 3 m/s),for the alloy and the composites.The results revealed that wear rate increased with increasing load and increasing sliding distance,whereas the wear rate decreased and then increased with increasing sliding velocity.The primary wear mechanism encountered at low loads was mild adhesive wear,whereas that at high loads was severe delamination wear.An oxide layer was formed at low velocities,whereas a combination of shear and plastic deformation occurred at high velocities.The mechanism at short sliding distances was ploughing action of Si3N4 particles,which act as protrusions;by contrast,at long sliding distances,direct metal-metal contact occurred.Among the investigated samples,the Cu/10wt％ Si3N4 composite exhibited the best wear resistance at a load of 10 N,a velocity of 2 m/s,and a sliding distance of 500 m.     

第二代丙烯酸酯类胶粘剂固化体系的研究

本文应用DSC法对SGA的固化体系进行了研究,探讨了两种氧化—还原引发体系及其用量变化对体系固化速度的影响,测定了该固化体系的活化能E_0值。     

防震膨胀胶的研制

本文以氯丁橡胶、树脂等为主要原料,通过添加增粘剂、填料、泡孔控制剂研制出了一种溶剂型的防震膨胀胶,它适用于未去油污的金属缝隙等处的粘接,以起到消音减震作用。文中主要研究了增粘剂、填实、混合溶剂的配比及泡孔控制剂对该胶性能的影响。     

沥青与矿料粘附性的测定方法

探讨采用粘附功试验表征沥青与矿料粘附性的可行性,以润湿-吸附理论为基础,讨论了沥青与矿料的粘附性与粘附力的内在关系;分析了沥青矿料表面润湿性能对界面粘结强度的影响,提出了以粘附功作为沥青与矿料粘附性的表征指标,设计了以沥青表面张力γ以及沥青在矿料表面接触面θ为基本参数的试验方法;最后对微观分析和水煮试验结果进行了比较.结果表明,粘附功试验表征沥青与矿料粘附性是可行的,试验数据精确,可达到0.01×10-3 N/m.     

固载TiO2光催化剂的制备与光催化性能

以玻璃纤维布为载体,分别用浸渍法和黏结剂法制备了负载型TiO2光催化剂,用SEM观察了2种方法中TiO2在玻璃纤维表面的负载情况。实验中以甲基橙为对象,以紫外线高压汞灯为光源,用所制备的2种玻璃纤维固定化TiO2光催化剂对甲基橙进行了光降解研究;分析了黏结剂法中黏结剂对TiO2光催化性能的影响;并分析了2种负载型光催化剂涂层与基体间的结合牢固性。结果表明,2种负载型光催化剂对甲基橙都有较好地脱色效果,而且两者与基体结合牢固性均良好。     

定向电结晶法制备纳米针锥晶布阵材料

通过定向电结晶方法制备了镍基针锥晶布阵材料.用扫描电子显微镜(SEM)研究发现,在电沉积初始阶段形成大量晶核,随着沉积过程的进行,晶核不断纵向生长,从而形成针锥晶.透射电子显微镜(TEM)结果表明,定向电结晶法获得的镍基针锥晶材料的每一个针锥晶体均为单晶体.由于针锥结构的物理镶嵌咬合等作用,针推晶表面与TiO2膜即使在高温烧结后也无开裂、起皮现象,针锥晶布阵材料与陶瓷薄膜表现了良好的结合性能.     

Size effect in nanoadhesion of fibrillar structure

The gecko has incredible climbing ability for its nanoscale hierarchical fibrillar structure foot-hair. Can we fabricate a new type of adhesive by mimicking the gecko mechanism? In this paper, we consider a simplified case of an elastic cylinder with hemispherical shape terminals adhering to a rigid substrate. By using the classical JKR model to calculate the adhesive strength, we find that the strong size effect arises when the cylinder's radius is in nanoscale. This finding may help us to design a biomemetic adhesive.     

卡森流体管流的减阻机理及减阻率计算

分析了流体与固体管壁之间的粘附功,揭示了卡森流体管内流动时的减阻机理,认为流体在流动过程中滑移的产生是减阻的本质. 推导出了卡森流体的减阻率表达式,讨论了各参量对减阻率的影响,并提出了实现卡森流体减阻的措施.     

CR/MMA/SBS三元接枝共聚胶粘剂的研制

针对CR和CR／MMA二元接枝共聚胶粘粘力低，剥离强度低这一问题，研制了CR／MMA／SBS三元接枝共聚胶粘剂，并测定了该胶粘剂的有关物性，结果表明：该胶粘剂的粘结强度（尤其是初粘强度）和剥离强度有明显的提高，文中叙述了该胶粘剂的制备方法以及主要反应条件对接枝共聚的影响。     

荧光分析法研究偶联剂与牙体组织的联结机理

为了进一步探讨牙体组织与粘接剂的粘接机理，我们研制了具有荧光的粘接偶联剂CGE（N）－1，用固体荧光分析方法对CGE（N）－1，牙体组织，及CGE（N）－1丙酮溶液处理后的牙体组织进行了分析测试。结果表明：用偶联剂处理后的牙面其荧光光普与未处理的相比发生了明显的红移；说明偶联剂同牙体组织之间发生了化学结合，溶液中的测试结果也证明了上述结论。