原位自生(TiB+La_2O_3)/TC4钛基复合材料的显微组织和力学性能

利用钛与镧、硼单质之间的原位反应,经真空自耗电弧熔炼与后续的热加工工艺制备了增强体含量不同的(TiB+La2O3)/TC4钛基复合材料,并研究了它的显微组织和室温拉伸性能。结果表明:该复合材料的基体为网篮状组织,增强体分布均匀,其中TiB呈短纤维状并沿加工方向分布,La2O3呈短棒状或颗粒状;与基体TC4合金相比,复合材料的室温抗拉强度均有所提高,且随着TiB与La2O3增强体含量的增多而增大,增强体起到了较好的增强作用;复合材料的拉伸断裂方式均为韧性断裂。     

原位自生(TiC+TiB)/Ti复合材料的显微组织与残余应力

通过钛、石墨、二硼化钛间的原位反应,并经真空熔炼、锻造、退火后制备得到了不同增强体(TiC,TiB)含量的(TiC+TiB)/Ti复合材料,研究了其物相组成与显微组织,并测试了其残余应力,通过建立残余应力数值拟合公式分析了微观残余应力之间的耦合关系。结果表明:钛基复合材料的基体组织为变形α组织,增强体分布均匀,其中TiC呈等轴状和不规则状,TiB呈短纤维状并沿锻造方向排列;TiC和TiB与钛基体因热膨胀系数不同而产生的微观残余应力分别为拉应力和压应力,当TiC与TiB体积比为1…1时微观残余应力的耦合系数为2.0。     

偶联剂处理碳酸钙晶须对聚醚醚酮摩擦磨损性能的影响

使用耐高温SPEEK偶联剂对碳酸钙晶须进行表面处理,利用热压成型方法制备质量分数为0~30%的碳酸钙晶须增强聚醚醚酮(PEEK)复合材料,在MM-200型磨损试验机上测试复合材料与45#钢环配副的摩擦磨损性能,利用扫描电子显微镜观察磨损表面形貌,分析磨损机制。结果表明,SPEEK偶联剂改善了晶须与PEEK基体的界面结合,提高晶须的力学增强效果,复合材料的减摩和耐磨性能显著提高。填充10%~25%晶须,复合材料具有较好的摩擦磨损性能。碳酸钙晶须提高了复合材料承载能力,减少摩擦副表面粘着,阻止树脂的热塑性变形,复合材料磨损以磨粒磨损和疲劳磨损为主。     

TiC、TiB增强钛基复合材料的高温氧化性能及微观结构

针对钛基复合材料高温应用中的关键问题——高温氧化性能，从理论和实验上研究了不同增强体(TiC、TiB)对钛基复合材料氧化性能和微观结构的影响。结果表明：钛基复合材料的氧化规律为抛物线规律，TiB增强体比TiC增强体更能提高复合材料的高温抗氧化性能，TiB／Ti基复合材料表面氧化膜的状态较TiC／Ti基的致密、均匀，高温氧化后，基体元素Ti和Al会与氧发生反应生成TiO2、Al2O3。     

行进速度对搅拌摩擦加工高熵合金增强铝基复合材料组织与性能的影响

采用搅拌摩擦加工技术制备了FeCoNiCrAl高熵合金颗粒增强AA5083铝基复合材料,研究了行进速度(45,60,75 mm·min-1)对复合材料中高熵合金颗粒分布、显微硬度和耐磨性能的影响.结果表明:制备的复合材料中没有新相生成,复合材料的显微硬度高于铝合金基体的;随着行进速度的增加,高熵合金颗粒的分布均匀性变差,复合材料的显微硬度略微降低;复合材料的平均摩擦因数和磨损率均较铝合金基体的低;随着行进速度的增加,复合材料摩擦因数和磨损率均增大,耐磨性能下降;复合材料和铝合金的磨损机制分别为磨粒磨损和黏着磨损.     

原位自生非连续颗粒增强钛基复合材料的组织和力学性能

以海绵钛、镧粉、TiB2粉和石墨粉为原料,通过原位反应分别制备得到1%(体积分数,下同)La2O3、5%TiB+1%La2O3、5%TiC+1%La2O3等3种增强体增强钛基复合材料,研究了复合材料的显微组织和力学性能,并与相同工艺所得纯钛的进行了对比。结果表明:复合材料的基体组织为α-Ti,原位生成的La2O3呈颗粒状或短棒状,TiB呈短纤维状,并沿锻造方向排列,TiC呈等轴状和不规则形状;所得钛基复合材料的硬度、抗拉强度和屈服强度均显著高于纯钛的,断后伸长率低于纯钛的。     

(TiB+TiC)/TC4钛基复合材料电解加工基础试验研究

针对钛基复合材料及其基体材料展开电解电化学特性研究,测量了TC4及(TiB+TiC)/TC4复合材料在NaNO3溶液中的极化曲线和电流效率.研究发现,(TiB+TiC)/TC4复合材料相较于TC4分解电压更高,电流效率更低.选用合适的加工参数进行(TiB+TiC)/TC4复合材料的电解铣磨粗、精加工.结果表明:粗加工后平整性较差,有明显的接刀痕,反应面存在大量未脱落的晶须状增强相,表面粗糙度Ra为5.262μm.精加工后具有较好的平整性,可以观察到金属光泽与磨削的痕迹,表面粗糙度Ra减小至0.702μm.     

搅拌摩擦加工道次对PI/7075铝基复合材料显微组织和耐磨性能的影响

在7075铝合金表面预置聚酰亚胺(PI)颗粒,利用搅拌摩擦加工(FSP)技术在不同加工道次下制备PI/7075铝基复合材料,研究了加工道次对复合材料显微组织和耐磨性能的影响。结果表明:增加加工道次可以减少复合材料内部缺陷,提高晶粒细化程度以及PI颗粒在铝合金基体中的分散性;复合材料的耐磨性能优于7075铝合金的,且随着加工道次的增加,耐磨性能提高;不同道次搅拌摩擦加工复合材料的磨损表面均存在少量犁沟和较浅的磨痕,其磨损机制均为黏着磨损和磨粒磨损。     

(TiB+TiC)/TC4钛基复合材料电解加工基础试验研究

针对钛基复合材料及其基体材料展开电解电化学特性研究,测量了TC4及(TiB+TiC)/TC4复合材料在NaNO3溶液中的极化曲线和电流效率.研究发现,(TiB+TiC)/TC4复合材料相较于TC4分解电压更高,电流效率更低.选用合适的加工参数进行(TiB+TiC)/TC4复合材料的电解铣磨粗、精加工.结果表明:粗加工后平整性较差,有明显的接刀痕,反应面存在大量未脱落的晶须状增强相,表面粗糙度Ra为5.262μm.精加工后具有较好的平整性,可以观察到金属光泽与磨削的痕迹,表面粗糙度Ra减小至0.702μm.     

真空实型铸造钢基表面复合材料的耐磨冲击性能研究

测试了真空实型铸造工艺制备的碳化硅颗粒增强钢基表面复合材料的耐磨性能和冲击力学性能。结果表明钢基表面复合材料的耐磨性优于基体,磨损系数大于基体;在应变率为600 s-1时,冲击应力比基体高约70 MPa。微观组织分析表明,增强碳化硅颗粒在基体中粒形基本保持完整,分布均匀,且基体与复合层之间没有明显的边界,说明两者的结合强度较高,起到了传递载荷和减缓冲击的作用。     

Comparison of tribological behavior of nylon composites filled with zinc oxide particles and whiskers

Mechanical properties and tribological behavior of nylon composites filled with zinc oxides were investigated in this paper. Different effects of ZnO particles and ZnO whiskers filling on the friction and wear behavior of nylon 1010 (PA1010) composites under dry friction condition were observed. The hardness, tensile strength and scratch coefficients of two kinds of nylon composites filled with the ZnO particles and whiskers were measured. Experimental results show that ZnO particles and ZnO whiskers improve the mechanical and tribological properties of nylon composites without affecting the crystallinity of nylon matrix. Hardness, tensile strength and scratch coefficient of composites are increased by the addition of ZnO particles and ZnO whiskers. Filler shape has little effect on the friction coefficients of nylon-based composites. These composites filled with particles and whiskers have nearly the same friction coefficients which locate between 0.4 and 0.45. The wear rates of composites are strongly dependent on filler shape and filler content. Particle-filled composites exhibit the lower wear rates than whisker-filled composites when the content of filler is lower than 10 wt.%. After that, the case is reversed. Ploughing and adhesion are the main wear mechanisms of composites with the addition of both ZnO particles and ZnO whiskers.     

硫酸钙晶须填充PTFE复合材料的摩擦学性能研究

用硫酸钙晶须(CSW )填充改性聚四氟乙烯(MVE),采用模压成型工艺制备不同硫酸钙晶须含量的PTFE/CSW复合材料;利用摩擦磨损试验机研究硫酸钙晶须对PTFE/CSW复合材料摩擦学性能的影响,利用扫描电子显微镜对PM复合材料的磨损表面进行微观分析.结果表明:填充硫酸钙晶须提高PTFE复合材料的耐磨损性能,但复合材料的摩擦因数略高于纯PTFE;纯PTFE的磨损机制为黏着磨损,而PTFE/CSW复合材料的磨损机制为轻微磨粒磨损和黏着磨损共同作用.当硫酸钙晶须质量分数大于10%时,PTFE/CSW复合材料的磨损机制逐渐转变为严重的磨粒磨损.     

Tribology of titanium boride-coated titanium balls against alumina ceramic: Wear, friction, and micromechanisms

The tribological performance of titanium alloy (Ti–6Al–4V) balls coated with a dual boride layer comprised of titanium diboride (TiB₂) and titanium boride (TiB) whiskers mated against alumina ceramic disks has been determined using lubricated ball-on-disk wear testing. Measurements of coefficient of friction values and volumetric wear were made and electron microscopic investigation of wear spots and tracks was performed. The wear rate of the boride-coated titanium alloy balls was 40 times less than that of 97% dense alumina balls. Measurements of wear track width and depth corroborated this result. The superior wear resistance is attributed to the hardness and the unique structure of the dual (TiB₂ + TiB) whisker layer and the consequent smoothness of the wear surface created during the wear process. The material removal mechanism is abrasive in nature in the boride-coated balls compared to grain fracture and pullout in alumina.     

硫酸钙晶须填充UHMWPE复合材料的摩擦磨损性能

以硫酸钙晶须(CSW)作为填料填充改性超高分子量聚乙烯(UHMWPE),采用热压成型法制备了不同硫酸钙晶须含量的UHMWPE/CSW复合材料;在销-盘摩擦磨损试验机上考察了硫酸钙晶须对UHMWPE/CSW复合材料摩擦学性能的影响,利用扫描电子显微镜对UHMWPE复合材料的磨损表面进行了微观分析。结果表明:随着硫酸钙晶须填充量的增加,复合材料的硬度逐渐增大,耐磨性能逐渐增加,摩擦因数逐渐减小;当硫酸钙晶须填充质量分数为20%时,UHMWPE/CSW复合材料的摩擦学性能最好。     

Tribological behaviors of hierarchical porous PEEK composites with mesoporous titanium oxide whisker

Hierarchical porous PEEK self-lubricating composites were prepared by mold-leaching and vacuum melting process under high temperature. The tribological behaviors were investigated for the porous PEEK composite and the porous composite after incorporating micro-porogen (NaCl) and mesoporous titanium oxide whiskers. If only micro-porogen was incorporated, the lowest steady state specific wear rate was observed for PEEK composites filled with 30% NaCl. Based on this porous PEEK composite, the effects of mesoporous titanium oxide whiskers and non-perforated titanium oxide whiskers on the friction and wear properties of PEEK composites were studied. Results showed that nano-micro porous PEEK composites with 30 wt% micro-porogen and 5 wt% mesoporous titanium oxide whiskers reached the lowest friction coefficient and specific wear rate, which were recorded as 0.0194 and 2.135×10^–16 m³/Nm under the load of 200 N. Compared with 15 wt% carbon fiber-reinforced PEEK composite which is widely used in industry, the wear resistance of the designed hierarchical porous PEEK composite increased by 41 times, showing outstanding wear resistance.     

氧化锌晶须填充尼龙1010复合材料的摩擦磨损性能

采用模具挤压成型的方法制备了氧化锌晶须填充尼龙1010复合材料,使用纳米力学测试系统测试了不同含量氧化锌晶须复合材料的硬度和弹性模量,在UMT试验机上考察了复合材料的摩擦磨损性能,然后对磨损表面进行了SEM观察。结果表明：复合材料的硬度和弹性模量随氧化锌晶须含量的增加而增大;ZnOw在保持尼龙1010摩擦性能的同时,可使其耐磨性能提高60％左右。纯尼龙的主要磨损机制为粘着磨损和熔融,填充ZnOw后复合材料的磨损机制转变为疲劳剥层。     

TiB2陶瓷颗粒增强电弧喷涂涂层滑动磨损性能的研究

采用电弧喷涂含TiB2陶瓷粉末的粉芯丝材,在低碳钢基体上制备了NiCr-TiB2和304L-TiB2金属基复合涂层,在摩擦磨损试验机上研究了按环/块线接触方式作往复运动条件下无润滑时室温下的摩擦磨损性能,利用光学显微镜、扫描电子显微镜和X射线衍射仪对涂层的显微组织结构、磨损表面及其相组成进行分析。结果表明,涂层的相对耐磨性能远高于碳钢基体,约为9到11.5倍。304L-TiB2涂层的低磨损率除了与硬质相有关,还和涂层具有较高的硬度有关。NiCr-TiB2涂层的耐磨性能好,细小的TiB2陶瓷相在局部涂层中连成网状,与基体结合良好,有效提高了涂层的磨损性能。     

材料增强用碳化硼颗粒表面改性涂层的研究

介绍用一种蒸 镀的方法在碳化硼颗粒（B4Cp）表面涂覆一层含钛金属的涂层，使得金属基复合材料的B4Cp-Me体系中的界面结合强度得到改善。 通过X射线衍射、差热分析和热重分析等分析了涂的结构变化，用粉末冶金法制备了B4C颗粒增强Cu、Al基复合材料，通过磨损实验评价了界面结合强度。试验结果表明，经涂覆后B4Cp表面的结构组成由内向外依次为B4C、TiB2、TiN。差热分析也证实了涂覆后的B4Cp表面产生新的物相，热重分析表明经涂覆后的B4Cp的热稳定性较末涂覆的高。磨损实验表明，使用经过涂覆的颗粒所制备的复合材料具有更高的耐磨性。     

The wear properties of an SiC-whisker-reinforced aluminium composite

The wear behaviour of an SiC-whisker-reinforced aluminium (SiC_w-Al) composite is studied by comparative testing. The experimental results show that the SiC_w-Al composite exhibits a fairly good wear resistance, especially for higher sliding velocities and/or higher loads in the test. The results are considered to be due to the high hardness of the SiC whiskers, the rotation of the SiC whiskers and the constraint of the SiC whisker in the aluminium matrix. It is also discovered by experiment that during the wear of oxides the wear volume of both the SiC_w-Al composite and the aluminium is small, but the wear volume of the former is a little larger than that of the latter. The reason may be that the compactness of the oxide on the surface of the specimen is damaged because of the existence of the SiC whiskers.     

原位合成钛基复合材料的高温力学性能

利用钛与B4C反应经普通的熔铸工艺制备了原位合成TiB和TiC增强的钛基复合材料。研究了原位合成钛基复合材料的高温力学性能和断裂机理。结果表明：随着温度的升高，其抗拉强度降低，伸长率提高。但与基体钛合金比较，由于原位合成增强体非常稳定，能有效地强化基体合金，明显提高了复合材料的高温抗拉强度。拉伸断裂机理与温度有关，室温时，增强体断裂是材料失效的主要原因；而随着温度的提高，增强体与基体合金界面脱粘成为材料失效的主要原因。