ZrN涂层刀具的滑动磨损特性研究

山东大学摘要:采用电弧离子镀法在硬质合金刀具表面制备了厚度为2.19~5.23μm的ZrN系列涂层,测定了涂层的显微硬度,并通过划痕试验和摩擦磨损试验考察了涂层与基体的结合强度及其摩擦磨损性能。在扫描电镜下观察磨损表面形貌,结果表明:ZrN系列涂层能够显著提高硬质合金刀具的表面硬度;涂层与基体的结合强度较高,划痕临界载荷高于60N;与此同时,电弧离子镀法ZrN系列涂层可以显著改善硬质合金刀具的耐磨性能。磨损机理主要是磨粒磨损和涂层的微剥落。     

Cu添加对等离子喷涂Al_2O_3涂层和AT13涂层性能的影响

在20钢表面运用等离子喷涂技术分别制备了Cu-Al_2O_3涂层和Cu-AT13涂层,并测试了涂层显微硬度、结合强度以及摩擦学性能。结果表明,Cu-Al_2O_3涂层较Cu-AT13涂层,平均显微硬度提高,结合强度减小,摩擦系数降低,磨损率降低,两种复合涂层的主要磨损机制均为剥落。     

NiTi合金表面改性及其微动磨损性能研究

采用多弧离子镀技术在NiTi形状记忆合金表面制备TiN涂层。利用SRVⅢ摩擦磨损试验机研究NiTi合金表面改性后在37℃Hank’s模拟体液中微动磨损性能,分析法向载荷对TiN合金磨损机制的影响规律。利用SEM扫描电镜及能谱考察磨损表面形貌,结果表明：制备的TiN涂层表面致密均匀,无明显缺陷。说明TiN涂层可有效提高基体的耐磨性能,其磨损机制主要表现为剥落损伤与磨粒磨损并存。TiN涂层显微硬度为784 HV,远高于基体,TiN/NiTi膜基硬度比缓慢下降,涂层与基体结合强度高。     

瓦楞辊表面等离子喷涂Cr2O3涂层性能研究

利用等离子喷涂技术在瓦楞辊材料42CrMo合金钢表面涂镀Cr2O3硬质涂层,以期提高材料表面耐磨性能.用显微硬度仪测试涂层的硬度,用MFT-4000型高速往复摩擦磨损试验机对涂层进行耐磨性能试验.并用扫描电镜(SEM)、X光衍射仪(XRD)分析了涂层的截面形貌和相结构.结果表明:等离子喷涂Cr2O3涂层后试样表面硬度达到HV1 184.1,试样表面摩擦因数减小,抗磨损性能大幅提高.     

高速电弧喷涂Al-Ni-Mm-Co涂层在脂润滑下的摩擦磨损性能

针对铝合金硬度低、耐磨性差的问题,采用电弧喷涂分别在6061铝合金基体表面喷涂Al和Al-Ni-Mm-Co涂层,采用显微硬度计、扫描电子显微镜、X射线衍射仪分别对涂层硬度、涂层显微结构、涂层成分进行分析。采用球-盘式往复摩擦试验机考察涂层在脂润滑下的摩擦学性能,并对磨痕形貌和表面主要元素进行观察。结果表明,Al-Ni-Mm-Co涂层的减摩性和抗磨性能均优于6061铝合金和Al涂层,其优异的摩擦学性能归结为摩擦表面形成的Al2O3、NiO、CoO等氧化保护层,主要的磨损形式为疲劳磨损。     

铝添加对等离子喷涂氧化铝涂层摩擦磨损性能的影响

采用等离子喷涂工艺制备氧化铝涂层,考察其摩擦磨损性能。利用SEM和OM对涂层显微结构和磨损形貌进行分析,考察了涂层的气孔率、显微硬度、结合强度和导温性能等。结果表明:由于金属铝良好的导热和延展性能,适量的添加铝在一定程度上改善了氧化铝涂层的层间结合和导温性能,也提高了涂层的耐磨性能。     

不同喷涂工艺制备的Al_2O_3-13%TiO_2涂层表面自由能与冲蚀磨损性能研究

采用接触角测量仪和冲蚀磨损试验机等设备,研究超声速等离子喷涂与普通大气等离子喷涂两种技术制备的Al_2O_3-13%TiO_2涂层的表面自由能和冲蚀磨损性能,并对涂层的显微硬度、孔隙率及成分进行检测分析。研究结果表明,普通大气等离子喷涂技术制备的涂层,其表面和内部结构疏松,孔隙率及显微硬度分别为6.653%和836.93 HV0.1。而超声速等离子喷涂技术制备的涂层,孔隙率及显微硬度分别为3.467%和1 078.68 HV0.1,相比普通大气等离子喷涂而言,超声速等离子喷涂制备的涂层整体性能较为优异。通过对两种涂层的结构和表面自由能分析发现,超声速等离子喷涂Al_2O_3-13%TiO_2涂层由于结构致密、表面自由能较低而具有较为出色的冲蚀磨损性能。     

ZL104合金表面反应等离子喷涂TiN复相涂层的组织和性能

采用反应等离子喷涂技术在ZL104合金基体上依次沉积NiCrAl黏结层和TiN复相涂层,通过X射线衍射、组织观察、硬度测试、拉伸及磨损试验等方法研究了涂层的物相组成、微观形貌、结合强度、硬度及耐磨性能,并探讨了磨损机制。结果表明:复相涂层由TiN、TiN_(0.3)和少量TiO_2组成,其组织致密,存在少量孔隙和微裂纹;涂层与ZL104合金结合良好,结合强度达17.7MPa;TiN复相涂层的平均显微硬度为1 330HV,约为基体的22倍,磨损量随载荷的增加而增加,且远小于基体的;ZL104合金的磨损机制为微切削磨粒磨损和微疲劳磨损,TiN复相涂层的为微切削磨粒磨损。     

氧化镧掺杂对等离子喷涂Al_2O_3-40%TiO_2涂层组织和耐磨性能的影响

在45#钢基体上大气等离子喷涂制备了Al2O3-40%TiO2(AT40)以及添加不同含量La2O3稀土的陶瓷涂层,利用X射线衍射和扫描电镜对涂层的组织结构和形貌进行了研究,并分析了涂层的显微硬度和磨损性能.研究结果表明:添加稀土的AT40涂层主要是由Al2O3、Al2TiO5和LaAl11O8相组成.基体与粘结层以及陶瓷层与粘结层之间形成良好的机械结合界面.添加稀土的涂层孔隙率降低,显微硬度和断裂韧性略有增加.在相同的摩擦磨损试验条件下,稀土/AT40涂层比AT40涂层具有更好的耐磨性,磨损机制都主要是脆性剥落磨损和粘着磨损.     

铝合金表面添加La_2O_3激光熔覆Ni基WC金属陶瓷涂层研究

添加适量La2O3,采用自配的熔覆材料在ZL108表面激光熔覆制备了Ni基WC金属陶瓷复合涂层,对熔覆层进行了显微组织和能谱分析、显微硬度测量以及室温下的干滑动摩擦磨损试验。结果表明,在铝合金表面激光熔覆处理时添加适量La2O3获得的Ni基WC金属陶瓷增强涂层无裂纹,组织细小,致密,WC颗粒增强相与基体之间结合良好。室温下熔覆层的磨损主要为显微切削和粘着磨损,干摩擦磨损性能优良。     

Tribological behavior of plasma sprayed Cr2O3-3%TiO2 coatings

Tribological behaviors of plasma-sprayed conventional and nanostructured Cr₂O₃-3%TiO₂ ceramic coatings (i.e., CC3T and NC3T, respectively) using pin on disc type dry sliding and pot type slurry erosion test were investigated in the present work. The experimental results indicated that there were two main wear mechanisms, plastic smearing and adhesive tearing, in the worn coatings under dry sliding. Plastic smearing corresponded to a lower average friction coefficient and wear rate, while adhesive tearing corresponded to higher values. The erosive environment selected for the slurry erosion experiments include 10, 20 and 30% of SiO₂ slurry concentrations in water with particle size 75-106 μm. The main damage mechanism observed in all the coatings submitted to slurry erosion were the formation and propagation of brittle cracks resulting in the detachment of coating surface material. Microstructural investigation was also carried to investigate the wear and erosion mechanism of the coatings using FE-SEM and EDS analysis. Properties like microhardness and porosity were also investigated for these coatings. Tribological performance of NC3T was better as compared to CC3T as observed in the present work.     

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。     

Influence of Polyfluo-Wax on the Friction and Wear Behavior of Polyimide/Epoxy Resin–Molybdenum Disulfide Bonded Solid Lubricant Coating

Polyimide/Epoxy resin–molybdenum disulfide bonded solid lubricant coatings (denoted as PI/EP-MoS₂) were prepared. The influence of polyfluo-wax (denoted as PFW) on the microhardness and friction and wear behavior of as-prepared PI/EP-MoS₂ lubricant coating was measured using a microhardness tester and a reciprocating ball-on-disc tribometer, respectively. The worn surfaces of the lubricant coatings were observed with a scanning electron microscope, and their wear rate was determined with a Micro XAM surface mapping microscope. Moreover, the transfer films formed on the counterpart steel ball surfaces were analyzed by X-ray photoelectron spectroscopy. Results indicate that the incorporation of a proper content of PFW filler is effective at improving the antifriction performance of the PI/EP-MoS₂ lubricant coating while maintaining better wear resistance. Moreover, the friction coefficient of the lubricant coating decreases with increasing content of PFW from 2 to 10%, and the one with a filler content over 6% PFW has a steady friction coefficient of 0.07. The improvement in the antifriction performance of the lubricant coating with the incorporation of the PFW filler is attributed to the excellent lubricity of homogeneously distributed PFW.     

不同铁含量镍-铁合金镀层的摩擦磨损性能

采用电沉积方法在LY12CZ铝合金表面制备了不同铁含量的镍-铁合金镀层,研究了铁含量对合金镀层硬度和摩擦磨损性能的影响;并根据镀层的磨损形貌探讨了其磨损机理。结果表明:当铁含量低于12.63%(原子分数,下同)时,随着铁含量增加,镀层的硬度增加,摩擦因数减小,耐磨性能提高;当铁含量为由12.63%增至23.59%时,镀层的摩擦因数略有增加,硬度和耐磨性能有所降低;镍镀层的主要磨损机理为显微推碾,随着铁含量的增加,镍-铁合金镀层的磨损机理由显微推碾转变为显微切削。     

Comparison of wear behaviour of plasma-sprayed Al2O3 coatings with and without laser treatment

This paper studies experimentally the effects of CO₂ laser-treatment on the wear behaviour of plasma-sprayed Al₂O₃ coatings, in linear contact sliding (dry, abrasive and lubricated) against SAE 4620 steel. Tests were carried out using a block-on-ring friction and wear tester, under different loads at different speeds. The wear mechanism and the changes in adherence, porosity and microstructure by laser treatment were also investigated. Results show a better wear behaviour for both laser-treated ceramic coating and its paired steel under dry and abrasive conditions, compared with the case without laser treatment. The lubricated wear behaviour of the laser-treated ceramic coating, however, is not improved. The changes in microhardness, porosity and adherence caused by the laser treatment are responsible for the change in wear behaviour of the ceramic coating.     

Y2O3改性石墨/CaF2/TiC/镍基合金复合涂层微观组织与摩擦学性能研究

为提高石墨/CaF₂/TiC/镍基合金（GCTN）复合涂层的力学性能和摩擦学性能,运用等离子喷涂技术在45钢表面制备了Y₂O₃改性GCTN复合涂层,研究了Y₂O₃对复合涂层的微观组织、显微硬度、断裂韧性和摩擦磨损性能的影响。结果表明：Y₂O₃改性GCTN复合涂层主要由γ-Ni、CrB、Cr7C₃、TiC、CaF₂和石墨等物相组成。Y₂O₃在等离子火焰加热作用下与C元素反应生成活性元素Y,Y净化了复合涂层的微观组织,并细化了CrB、Cr₃C7等硬质相晶粒,提高了其致密性。当Y₂O₃质量分数为0.5%时,复合涂层的显微硬度和断裂韧性分别为593.3MPa和6.82MPa·m^1/2,比不含Y₂O₃的复合涂层分别增大了8%和22%,其机理主要是Y₂O₃细化了CrB、Cr₃C₇等硬质相晶粒,起到了细化强化作用。由于GCTN-0.5Y₂O₃复合涂层的显微硬度和断裂韧性显著提高,减少了其黏着磨损和微观断裂磨损,因而GCTN-0.5Y₂O₃复合涂层的摩擦因数和磨损率最小,分别为0.085和0.39×10-3mm3/m。     

纺织机钢丝圈表面类金刚石膜的制备及摩擦特性研究

为提高纺织机高速纺纱工况下钢丝圈表面的磨损性能,采用直流等离子气相沉积法在钢丝圈表面制备类金刚石涂层(DLC),采用原位扫描探针显微镜观测涂层表面形貌,测量并计算涂层硬度。结果发现,DLC涂层颗粒粒径约为100 nm,呈岛状聚集分布,硬度约为18 GPa。采用球-盘式摩擦试验机研究DLC涂层在不同载荷(20~100 N)和不同转速(100~600 r/min)条件下的摩擦特性。结果表明,在低载高速的条件下,DLC涂层具有良好的耐磨特性,符合钢丝圈的实际工况。采用傅里叶变换红外光谱分析涂层的磨损机制,结果发现,在摩擦磨损过程中从薄膜中释放出来的氢和涂层的剪切变形引起了DLC薄膜的石墨化SP^3/SP^2转变,从而降低了摩擦因数和磨损率。     

镶嵌MoS2的Al2O3/TiC基陶瓷刀具材料微孔表面摩擦磨损性能研究

采用Nd:YAG激光器在Al2O3/TiC陶瓷刀具材料表面加工出不同密度的微孔,并涂覆填装MoS2固体润滑剂,在UMT-2摩擦磨损试验机上进行往复摩擦试验,研究其在不同载荷和速度下的摩擦磨损性能,通过白光干涉仪、光学显微镜和扫描电镜观察激光织构化后表面特征和磨损后表面形貌。结果表明:激光织构化后,陶瓷材料表面发生了氧化;在相同的实验条件下,与光滑表面相比较,填装MoS2固体润滑剂的微孔表面能够有效地降低摩擦因数,减小磨损率。这主要是由于填装在微孔中的润滑剂在摩擦作用下涂覆到基体表面,形成润滑膜,起到减摩降磨作用,同时激光加工后微孔周围凸起及氧化后形成的摩擦特性优良的TiO2也能起到良好的减摩降磨效果。通过对磨损形貌分析,光滑表面磨损较为严重,有大量的犁沟产生,主要的磨损形式为磨粒磨损及脆性断裂;微孔表面磨损较为轻微,其主要磨损发生在微孔周围。     

Performance of abrasive wear of WC-12Co coatings sprayed by HVOF

The performance of multimodal and conventional materials in the form of coatings deposited by high velocity oxy-fuel (HVOF) thermal spraying has been studied. WC-12Co coatings were deposited under same conditions using multimodal and conventional WC-12Co powder feedstocks. The phase composition of the feedstock powders and the coatings were analyzed by XRD. Abrasive wear resistances of coatings were carried out on wet sand rubber wheel abrasion tester. The characterizations of spraying feedstock powders, microstructure and surface micrographs of the prophase and anaphase attrition surfaces were performed by SEM. The results indicated the multimodal coating shows slight higher microhardness and better abrasive wear resistance than the conventional counterpart. Also, the thermally sprayed carbide-based coatings have excellent wear resistance with respect to the hard chrome coatings.