高温环境下超声深滚静压力对金属陶瓷涂层微观组织结构的影响

为提高金属陶瓷涂层与基体的结合性能，通过对Ni-WC金属陶瓷涂层实施电阻加热和超声深滚耦合处理，探究高温环境下不同超声深滚静压力对Ni-WC金属陶瓷涂层微观组织结构的影响。通过扫描电镜、X射线衍射仪和JADE软件对改性金属陶瓷涂层进行测试，通过分析改性金属陶瓷涂层的表面微观形貌、晶粒尺寸和表面残余应力，探讨改性金属陶瓷涂层结合强度，用ImageJ软件评价改性金属陶瓷涂层孔隙率。结果表明：高温下超声深滚提高了涂层表面光洁度，细化了晶粒，引入了残余压应力，提高了涂层综合性能；随静压力的增大，改性金属陶瓷涂层的表面微观形貌得到明显改善，表面残余压应力逐渐增大，涂层与基体之间形成了部分冶金结合，结合强度大大提高；静压力较大时出现了物相的转变，且随静压力的增大，其孔隙率也逐渐减小。     

PTA重型离心机的修复及改进

某PTA装置重型离心机在经过多年的使用后,存在处理能力严重下降、振动噪声大及运行周期短等制约装置平稳运行的问题。通过对磨损表面的激光焊接以及密封套的表面金属陶瓷强化,并对局部结构做了改进,采用SolidWorks建模、ANSYS应力分析,从理论上分析出设计的不足环节,有效地保证了修复方案的合理性。     

热等静压制备Ti(C,N)基金属陶瓷功能梯度材料

用热等静压（HIP）技术制备了Ti（C，N）基金属陶瓷功能梯度材料，对热等静压氮化处理前后的组织结构、硬度以及密度变化作了比较分析。结果表明：HIP技术能在金属陶瓷表面形成硬质薄膜，表面硬度提高，并且硬度由表及里逐渐减小，这是由于高温高压氮化处理使材料中的孔洞闭合，微裂纹和缺陷的减少使得材料性能显著提高。     

汽车金属摩擦表面再生技术剖析

本文对汽车金属摩擦表面再生技术进行了综合介绍,深入剖析了金属陶瓷层的形成机理、金属陶瓷层的特性和金属摩擦表面再生技术修复的累加特性,分析了我国金属摩擦表面再生技术在当前实际应用中存在的问题和发展前景。     

金属陶瓷表面复合材料制备技术

概述了国内外关于金属陶瓷表面复合材料制备技术的发展状况,介绍了各种制备方法,提出了目前金属陶瓷表面复合材料制备中存在的问题,并对其应用前景做出了展望。     

金属陶瓷喷涂技术用于PASSIM卷接机组胶辊磨损修复

针对PASSIM卷接机组供胶装置存在的问题,采用金属陶瓷喷涂技术,使接装机胶辊表面的耐磨损性和耐腐蚀性得到改善,保证了产品质量,提高了设备的有效作业率。     

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。     

稀土对金属陶瓷涂层微观组织改性作用研究现状和应用进展

介绍了稀土对金属陶瓷涂层微观组织改性作用的研究现状和应用进展.稀土对金属陶瓷涂层改性作用表现为细化晶粒、净化组织、产生固溶强化和弥散强化、降低基体材料对涂层的稀释、改善涂层组织力学性能等方面,从而改善了金属陶瓷涂层的微观组织结构.稀土改性技术应用于热喷涂、复合电镀、激光表面熔覆等金属陶瓷涂层制备工艺中,能有效地提高涂层的强度和硬度,增强涂层与基体的结合强度,改善涂层的摩擦学性能,提高金属陶瓷涂层的使用性能.     

金属陶瓷表面硬质涂层的制备及其与基体结合强度研究现状

金属陶瓷因既具备金属材料优异的强度、高温导热性和热稳定性，又具备陶瓷材料的耐高温、耐腐蚀等特性而广泛用于制造切削刀具。金属陶瓷耐磨性和硬度不足的问题限制了其应用范围，在其表面制备硬质涂层可以解决这一问题，但是涂层的结合强度弱，易剥落。介绍了硬质涂层的制备方法、涂层与基体结合强度的影响因素，阐述了提高硬质涂层结合强度的方法，最后对金属陶瓷表面硬质涂层的制备技术及结合强度的提高进行了展望。     

金属陶瓷粒子添加剂对摩擦副表面的影响

用MMW-1型销盘式摩擦磨损试验机,对含有金属陶瓷添加剂润滑油对气缸套-活塞环摩擦学特性的影响进行了模拟试验研究;用表面粗糙度仪测量了缸套试样的表面粗糙度;用原子力显微镜对缸套试样表面的微观形貌和摩擦力形貌进行了测试;用韦氏硬度仪测量了缸套试样的表面硬度变化。研究结果表明,气缸套试样表面在这种添加剂作用下,其表面粗糙度和峰高都大幅度降低,展现了金属陶瓷粒子良好的自修复能力,并且这种能力随载荷的增大而增强。表面硬度分析结果也表明,添加剂粒子与摩擦表面的作用也与载荷有关。     

Ultraprecision grinding of TiC-based cermet hemisphere couples

In aerospace industry, TiC-based cermet hemisphere couples are widely used as dry sliding bearing and gyro due to its high resistance to wear and heat. To enhance the grinding precision, this paper presents an ultraprecision grinding technique for machining TiC-based cermet hemisphere couples. The factors affecting the form and dimension accuracy of the hemisphere couples in ultraprecision grinding were analyzed theoretically. The optimization of grinding conditions and ground surface morphology of TiC-based cermets were investigated. In addition, the subsurface damage of ground TiC-based cermet hemisphere couples was observed by focused ion beam FIB. The research results show that position errors have more significant impact on concave in grinding of hemisphere couples. The TiC-based cermet ground surface revealed a smooth surface covered by micropits, traces, and reliefs because of the special material properties, and the surface roughness could be improved by the decrease of feed rate, while the different feed rates did not influence form accuracy. Finally, TiC-based cermet hemisphere couples with 16 nm surface roughness, 0.3 μm PV form accuracy, radius deviation of less than 3 μm, and subsurface damage depth of less than 2.5 μm were obtained.     

微米／纳米复合Ti（C，N）基金属陶瓷刀具切削铸铁的性能研究

利用热压烧结法制备了微米／纳米复合Ti（C,N）／Al2O3金属陶瓷刀具,对研制的三种金属陶瓷刀具（材料编号JT1-JT3）和YG8硬质合金刀具切削铸铁时的切削性能进行了试验研究。结果表明,研制的金属陶瓷刀具适合切削铸铁,其切削性能优于YG8,尤其是JT2刀具不但磨损较小,且加工表面质量较好。分析了刀具的磨损形貌和磨损机理,得出了Ti（C,N）金属陶瓷刀具的主要磨损机理为后刀面磨粒磨损的结论。     

超声辅助电火花粉末沉积WC-Ni金属陶瓷涂层的微观结构及摩擦学性能

针对传统电火花沉积工艺中工具电极预制成本高、工艺复杂、材料选择范围受限等问题,提出了一种超声辅助电火花粉末沉积（Ultrasonic-assisted electro-spark powder deposition,UEPD）的新方法。利用UEPD工艺成功地在316L不锈钢基材上制备了WC-Ni金属陶瓷涂层。所制备的WC-Ni金属陶瓷涂层的厚度为89~159 μm,表面粗糙度约为3.672 μm,并且与基材呈现良好的冶金结合。超声振动的引入能够有效改善涂层的成形质量。涂层的微观组织主要由亚微米级细小枝晶组成,主要物相包括FeNi、Cr₃Ni、WC、W₂C、Cr₂₃C₆和Cr₃C₂等。这些细小的晶粒和强化相使金属陶瓷涂层的硬度明显增加,平均硬度达到980.68 HV,约为基材的4.1倍。摩擦磨损性能测试表明,金属陶瓷涂层的磨损率相比基材和不含WC的Ni基合金涂层分别降低了50.7%和37.7%,并且还表现出明显低于二者的摩擦因数。WC-Ni金属陶瓷涂层的主要磨损机理为疲劳磨损和磨粒磨损,其中高硬度表面和具有颗粒流润滑效果的磨屑层是金属陶瓷涂层实现高耐磨、低摩擦的主要原因。UEPD工艺相比于传统的电火花沉积工艺省却了复杂的工具电极预制过程,其工艺更简单,成本更低廉、材料选择更广泛,并且所制备的涂层也表现出良好的成形质量和性能。这为电火花沉积技术的发展提供了一种新的思路。     

超细TiC0.7N0.3基金属陶瓷的切削性能研究

采用超细TiC0 7N0 3 粉制备了超细金属陶瓷刀片。该刀片加工 9CrSi调质钢时 ,寿命比普通金属陶瓷刀片提高 2～ 3倍 ,切削力小 ,切削轻快 ,被加工表面质量显著提高。讨论了该刀片切削性能改善的机理。     

重视热处理自主创新,突破我国制造业发展的瓶颈

热处理是决定制造业产品使用寿命和可靠性的关键工序,但国内存在重产品、轻单元技术和重产能、轻品质的倾向。热处理和表面改性的水平与国际先进水平相比存在很大差距,严重制约我国制造业自主创新能力的提升,难以跻身高端市场,应引起各部门和企业界的高度重视。建议开发和推广数字化的热处理智能技术,以计算机模拟和基于知识工程(KBE)为基础,优化热处理与表面改性工艺,开发高端工艺装备和智能控制技术,实现热处理的优质,高效、节能和清洁生产。     

The performance of ceramic and cermet cutting tools for the machining of austempered ductile iron

In this study, the machinability of austempered ductile iron (ADI) having a ferritic structure was examined. For this purpose, three types of ductile iron materials (as cast, ADI-250, ADI-375) and two different types of cutting tool materials (ceramics and cermet) were used. To emphasize the role of austempering process, ductile iron (DI) specimens are first austenitized in salt bath at 900°C for 120 minutes after which they are quenched in salt bath at 250°C (ADI-250) and 375°C (ADI-375) for 120 min. Machining tests were carried out at various cutting speeds (100–500 m/min) under the constant depth of cut and feed rate. The performance of both ceramic and cermet tools were evaluated based on the workpiece surface roughness and flank wear. Wear conditions of the cutting tools were characterized by scanning electron microscope. The results point out that the lower austempering temperature results in increasing of the cutting forces, while better surface roughness is obtained. Additionally, the results indicate that the tool wear occurs mainly on the flank face. However, higher cutting speed results in chipping formation in cermet cutting tool.     

High-performance circular sawing of AISI 1045 steel with cermet and tungsten carbide inserts

This work investigated the influence of cutting speed and feed rate on cutting forces, surface roughness, and slot width circular sawing of AISI 1045 steel. The effects of tool material (cermet and tungsten carbide) and geometry (chip breaker flute and pre-cutting/post-cutting teeth) were also investigated. Thrust and radial forces generally tended to decrease as the cutting speed increased and tended to increase with the feed rate. The lowest values of thrust and radial forces were obtained using a tungsten carbide saw ground with precutting and post-cutting teeth. With regard to the quality of the machined wall, the lowest surface roughness was obtained by applying the highest cutting speed and lowest feed rate and employing a cermet brazed saw. Under this condition, roughness values comparable to face turning and parting off operations were obtained. The cermet brazed saw was responsible for producing the narrowest slot widths.     

陶瓷润滑油添加剂对渗氮和镀铬缸套作用效果的研究

在含陶瓷添加剂润滑油润滑下,研究了添加剂分别对渗氮和镀铬两种缸套的作用效果,采用显微硬度计、纳米压痕仪、原子力显微镜和扫描电镜对缸套进行了测试分析.结果表明,该陶瓷添加剂大大改善了两种缸套表面粗糙度,使渗氮处理的缸套表面硬度有明显提高,使镀铬处理的缸套表面硬度有些许降低.光学显微照片和扫描电镜照片结果表明,添加剂作用后,镀铬缸套表面形成了一层极薄的分布不很均匀的透明物质,从而大大改善了摩擦表面的性能;添加剂对两种缸套的作用机制并不相同.     

性能优异的切削刀具材料——金属陶瓷

分析比较了金属陶瓷材料的性能特点 ,介绍了超细微粒金属陶瓷、涂层金属陶瓷、超韧金属陶瓷等新型金属陶瓷刀具材料的切削性能及适用范围。