MC尼龙/钛酸钾晶须复合材料制备及其摩擦学性能研究

为了考察和改善MC尼龙的吸水性对其摩擦学性能的影响,采用单体浇铸工艺制备了MC尼龙/钛酸钾晶须复合材料。经干摩擦实验后发现,未水浴处理试样的摩擦系数易受吸水性的影响而不稳定,而水浴处理试样的摩擦系数则能较快地达到稳定;MC尼龙/钛酸钾晶须复合材料的磨损以磨粒磨损为主,纯MC尼龙则以粘着磨损为主,水浴处理试样的总质量磨损率要小于未水浴处理试样,但吸水性对材料磨损特性的影响并不明显;水浴处理MC尼龙/钛酸钾晶须复合材料能明显改善吸水性对摩擦学性能的影响。     

含油MC尼龙复合材料的摩擦磨损性能研究

制备了一种轴承润滑油填充浇铸尼龙(MC尼龙)复合材料,并对其力学性能和摩擦磨损性能进行了研究。结果表明:润滑油的加入明显改善了MC尼龙的力学性能和摩擦磨损性能,提高了MC尼龙的韧性和摩擦系数;当润滑油用量为5%时,MC尼龙复合材料具有较高的强度和韧性,同时具有较低的摩擦系数和磨损量。     

聚甲亚胺改性MC尼龙复合材料干摩擦磨损特性

通过原位聚合法制备出由两种不同化学结构聚甲亚胺改性的MC尼龙复合材料,利用环-块形式对比研究了与45#钢环对磨时在不同磨损条件下的干摩擦磨损性能,并利用扫描电子显微镜对其磨损机理进行了分析。结果表明:在所测试的条件下,MC尼龙及其复合材料的摩擦系数随载荷的增加而逐步下降,聚甲亚胺在大多数条件下能够改善复合材料的耐磨损性能;在低速低载时,MC尼龙及其复合材料的磨损表面发生了明显的塑性形变,磨损机理为磨粒磨损和粘着磨损;高速高载时,磨损机理主要为粘着磨损和疲劳磨损。     

聚丙烯腈纤维/MC尼龙6原位复合材料摩擦磨损性能研究

本文利用己内酰胺的阴离子原位聚合方法制备了聚丙烯腈纤维/MC尼龙6原位复合材料。对复合材料的摩擦磨损性能进行了测试,通过DSC、SEM等测试手段对复合材料的摩擦磨损机理进行探讨。结果表明原位复合材料的磨损机理是以磨粒磨损为主,同时还有粘着磨损和疲劳磨损。摩擦温度是摩擦系数大小的影响因素。原位复合材料的摩擦系数随载荷的增加而减小,磨损量随着载荷的增加而增加。在低载荷条件下,原位复合材料的摩擦系数大于MC尼龙6,当载荷增加时,聚合物表面软化熔融,起到了润滑作用使得复合材料的摩擦系数下降。     

氧化处理对MC尼龙/C3D复合材料摩擦磨损性能的影响

以己内酰胺单体和经氧化处理的碳纤维三维编织物(C3D)为原料,采用原位聚合方法制备了C3D增强浇铸尼龙(MC尼龙/C3D)复合材料。在磨损试验机上进行了滑动摩擦试验,采用扫描电子显微镜对磨痕和磨屑形貌进行观察和分析,研究了氧化处理对MC尼龙/C3D复合材料摩擦学性能的影响。结果表明,C3D经过氧化处理后所制MC尼龙/C3D复合材料的摩擦系数明显小于C3D未经氧化处理的MC尼龙/C3D复合材料。随着载荷的增加,材料的摩擦系数增大,而磨损率减小;在较高滑动速度下,摩擦系数和磨损率均较小;从磨痕和磨屑形貌观察到,C3D经氧化处理后与基体结合好,而未经氧化处理的C3D与基体剥离,但是C3D经氧化处理的复合材料的磨损率在较高载荷下略有增大。表明,C3D的氧化处理提高了碳纤维与基体间的结合强度,同时在一定程度上提高了复合材料的摩擦学性能。     

碳材料摩擦性能浅谈

在转速和压力变化情况下,碳石墨材料与对磨件进行摩擦磨损试验,研究在不同转速和不同压力下,碳材料的摩擦系数、磨损值及表面状况,并通过试验了解碳材料摩擦磨损情况。结果试验表明:在一定载荷条件下,随着转速的增加,碳材料摩擦磨损性能因转速小先保持良好,但当随着转速增加,因摩擦过程产生热,使摩擦磨损性能变差,造成摩擦磨损趋于恶化。在一定转速条件下,随着载荷的增加,碳材料摩擦系数性能因载荷小先保持良好,但当随着载荷增加摩擦性能因润滑油不能进行入相接触界面,使碳石墨与对磨件形成干摩擦,造成磨损趋于恶化。     

纳米颗粒增强摩擦材料摩擦学性能研究

以丁腈橡胶改性酚醛树脂为基体,芳纶纤维、玻璃纤维为增强纤维,选用不同类型的纳米颗粒作为填料设计摩擦材料组分配比,并通过热压烧结制备摩擦材料。通过摩擦磨损试验机测试其在干摩擦条件下的摩擦学性能,并用扫描电镜(SEM)对材料的磨损形貌进行观察分析,以研究不同类型的纳米颗粒对摩擦材料性能的影响。研究表明:在干摩擦条件下,经过纳米颗粒改性的摩擦材料摩擦系数、硬度比未改性的材料有不同程度的提高,同时磨损率有很大程度的降低;纳米颗粒改性的摩擦材料摩擦系数、磨损率变化趋势具有一致性,均随着实验载荷、滑动速度的增大而逐渐减小;纳米颗粒改性后的摩擦材料磨损机理表现为疲劳磨损与磨粒磨损并存,而未改性的材料磨损机理主要表现为疲劳磨损。     

坡缕石/铟复合纳米添加剂对菜籽油的摩擦性能影响

为研究坡缕石/铟复合纳米添加剂对润滑油摩擦性能的影响,选取精炼菜籽油作为基础油,分别对加入不同配比添加剂的试油进行四球摩擦磨损试验机的极压试验和长磨试验。结果表明,当坡缕石/铟复合纳米添加剂在润滑油中的配比为1.5%时,润滑体系的摩擦性能最佳,与基础油相比,无卡咬最大负荷PB值提高了30.77%,烧结负荷PD值提高了一倍,磨斑直径WSD降低了32%,摩擦系数μ降低了17.24。     

碳纤维增强尼龙复合材料的摩擦性能研究

根据碱催化阴离子聚合原理 ,制备了连续长碳纤维增强单体浇铸尼龙复合材料 (简称CL/PA)。在MM -2 0 0型磨损试验机上考察了碳纤维含量和试验条件对其摩擦性能的影响 ,并利用扫描电子显微镜对其摩擦性能和磨损机制进行了考察。分析结果表明 :碳纤维的体积分数在 35 %左右时增强效果最好 ,CL/PA复合材料的摩擦系数和磨损率随着载荷的增加而减小。其磨损机制主要表现为粘着磨损和碳纤维的破碎和磨平的特征     

碳纤维增强尼龙复合材料的摩察性能研究

根据碱催化阴离子聚合原理，制备了连续长碳纤维增强单体浇铸尼龙复合材料（简称CL/PA）。在MM-200型磨损试验机上考察了碳纤维含量和试验条件对其摩擦性能的影响，并利用扫描电子显微镜对其摩擦性能和磨损机制进行了考察。分析结果表明：碳纤维的体积分数在35%左右时增强效果最好，CL/PA复合材料的摩擦系数和磨损率随着载荷的增加而减小。其磨损机制主要表现为粘着磨损和碳纤维的破碎和磨平的特征。     

MC尼龙6/纳米ZnO复合材料的研究

采用硅烷偶联剂KH-550修饰纳米ZnO,制备了MC尼龙6/纳米ZnO复合材料。力学性能测试表明,当纳米ZnO质量分数为1%时复合材料的力学性能最优,拉伸强度比纯MC尼龙6提高25.6%,断裂伸长率提高165.6%,简支梁冲击强度提高70.1%,这说明纳米ZnO可起到同时增强增韧的作用。扫描电子显微镜分析表明,纳米ZnO质量分数为1%时,纳米ZnO在MC尼龙6基体中分散最好,达到了纳米级分散;由X衍射分析发现,纳米ZnO没有改变MC尼龙6的结晶形态,纳米ZnO质量分数为1%时复合材料的结晶形态结构优越。     

载荷对各向同性热解炭干态摩擦磨损行为的影响

在室温干态条件下,利用环-块滑动摩擦实验研究了不同载荷下各向同性热解炭材料(IPyC)与热处理40Cr钢配副的摩擦磨损行为.结果表明:材料的摩擦性能受到载荷的影响,不同的载荷条件下,各向同性热解炭的摩擦系数为0.10～0.12,体积磨损量为0.15-0.30mm3.研究表明,不同载荷下形成的磨屑膜和转移膜是影响材料摩擦...     

The friction and wear properties of clay filled PA66

Polyamide 66(PA66)/clay nanocomposites were prepared by direct melt compounding. The mechanical and tribological properties were evaluated. It was found that addition of clay into PA66 increased the bending strength and microhardness of PA66. And also, the incorporation of clay can reduce the friction coefficient of PA66. The nanocomposites which have the mass fraction less than 5% show less wear rate compared with neat PA66. High fraction of clay can cause severe agglomerated abrasives. The differences in the friction and wear behaviors of PA66 and PA66/clay nanocomposites are attributed to the differences in their surface morphologies, transfer film characteristic. The agglomerated abrasives on the worn surface contribute to the increase of wear rate of nanocomposites of higher mass fraction clay. The friction and wear behaviors of PA66 and its nanocomposites under high temperature exhibit similar tendency with those under 25°C. POLYM. ENG. SCI., 48:203–209, 2008. © 2007 Society of Plastics Engineers     

Polydimethylsiloxane/monomer casting nylon copolymers: Preparation,flame-retardant properties,and wear-resistant properties

In order to improve the toughness, wear resistance, and combustion properties of the monomer casting nylon (MC nylon) materials, the polydimethylsiloxane (PDMS) segment is bonded to the nylon molecular chain by copolymerization. PDMS/MC nylon copolymers are prepared via in situ anionic polymerization with macro-activator based on PDMS terminated with hexamethylene diisocyanate. The effects of different macro-activator content on the mechanical properties, water absorption, thermal stability, friction and wear properties, and combustion properties of the copolymers are characterized. The results show that the impact strength of the copolymer improves significantly (optimally increases by 2.6 times) and the water absorption rate decreases with the increase of PDMS content. The introduction of the silicon–oxygen structure reduces the peak heat release rate of copolymer materials (optimally decreases about 28.7%), while it promotes the decomposition of the system, resulting in a slight decrease in the thermal stability of the materials. Adding 5 wt % PDMS can decrease the wear loss of MC nylon from 6.2 mg of pure nylon to 1.6 mg. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48753.     

Preparation and tribological properties of poly(methyl methacrylate)/styrene/MWNTs copolymer nanocomposites

Poly(methyl methacrylate)/styrene/multi‐walled carbon nanotubes (PMMA/PS/MWNTs) copolymer nanocomposites with different contents have been prepared successfully by means of in situ polymerization method. The structure and the microhardness of PMMA/PS/MWNTs copolymer nanocomposites were characterized. The tribological behaviors of the copolymer nanocomposites were investigated by a friction and wear tester under dry conditions. The relative humidity of the air was about 50% ± 10%. Comparing with pure PMMA/PS copolymer, the copolymer nanocomposites showed not only better wear resistance but also smaller friction coefficient. MWNTs could help the nanocomposites dramatically improve the wear resistance property. The mechanisms of the improvements on the tribological properties of the PMMA/PS/MWNTs copolymer nanocomposites were also discussed in detail. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and properties of wear-resistant and flame-retardant polyphenylsulfoneurea/monomer casting nylon copolymers

A poly(phenylsulfone)-urea (PPSUU) macro-activator is synthesized by in situ anionic polymerization of 4,4′-diaminodiphenylsulfone and hexamethylene diisocyanate. The PPSUU segment is embedded into the nylon molecular chain through copolymerization to improve the wear resistance and flame retardancy of monomer cast nylon 6 (MC PA6) materials. The mechanical properties, thermal stability, friction and wear properties and combustion heat release rate of copolymers with different macro-activator contents are tested. Results indicate that a small amount of PPSUU can improve the wear resistance and impact properties of nylon materials. The wear loss of MC nylon is 54.8% less than pure MC nylon from 1.049 × 10⁻⁸ to 0.474 × 10⁻⁸ g/Nm with 6 wt% PPSUU. Moreover, better flame retardancy is verified. The peak of HRR reduced 36.8% from 654 to 413 kw/m² with 4 wt% PPSUU, accompanied by advanced ignition time and flame extinction time, thus reducing the risk of fire.     

MC尼龙／Sm2O3纳米复合材料的制备及性能研究

用原位分散聚合法制备了一系列MC尼龙/Sm2O3纳米复合材料,并对其结构和力学性能进行了表征.结果表明,纳米Sm2O3使MC尼龙晶格尺寸发生了一定程度的改变;纳米Sm2O3的加入可以明显改善MC尼龙的力学性能,对MC尼龙同时具有增强和增韧双重效果;MC尼龙/Sm2O3纳米复合材料的力学性能随着纳米Sm2O3用量的增加呈先升高后降低的趋势.当纳米Sm2O3的质量分数为0.5%时,复合材料的拉伸强度和断裂伸长率达到最大值,分别比MC尼龙提高了18.8%和91.5%,当纳米Sm2O3的质量分数为1.0%时,复合材料的缺口冲击强度、穹曲强度和弯曲弹性模量达到最大值,分别比MC尼龙基体提高了36.6%、11.2%和11.5%.     

碳纤维增强MC尼龙复合材料吸湿行为研究

采用液态原位聚合法制备了碳纤维(CF)增强浇铸尼龙(MC尼龙)复合材料,研究了其吸湿行为?分别考察了CF体积分数、CF编织结构和外加载荷对MC尼龙／CF复合材料吸湿行为的影响。结果表明,随着CF体积分数的增加,复合材料的平衡吸湿率减小;三维编织结构的CF增强MC尼龙复合材料的吸湿速率及平衡吸湿率均低于长的CF增强MC尼龙;外加载荷使该复合材料的吸湿能力降低。