内燃机活塞环的等离子渗氮

本文阐述活塞环等离子渗氮设备、工艺及渗氮层的检测方法。活塞环经过等离子渗氮处理，提高了活塞环的表面硬度，耐磨性好。通过磨损实验发现经等离子渗氮的试样摩擦力矩小，即摩擦系数小，减摩性好。同时磨合接触面的温度低，有利于活塞环在缸套中高速运动时建立润滑油膜，提高了活塞环的抗咬合性，延长了活塞环的使用寿命。     

深冷处理对CrWMn钢组织性能影响

测定了经不同规范热处理后ＣｒＷＭｎ钢组织和性能。结果表明，与常规热处理、冷处理相比较，深冷处理使残余奥氏体量减少，硬度增加，耐磨性提高．但耐磨性并不始终随硬度增加而提高，只有硬度与韧性较好地匹配，才能得到较高的耐磨性．     

氮化处理应注意的一些问题

氮化能使钢件获得比渗碳更高的表面硬度、耐磨性、疲劳强度、红硬性以及抗咬合性,且氮化处理温度低、变形小,适用材料面广,不仅可用于传统的氮化钢,还可以用于工具钢、结构钢、不锈钢、铸铁等,因此氮化在机械制造业中应用甚广。近几年来又有进一步扩大应用范围的趋势,在许多要求变形小,承载、耐磨的零件,通过正确选材,确定合适的技术条件以及合理安排好冷热加工工序等措施,应用氮化处理都取得了令人满意的效果。 [1]正确选用氮化材料 　　不是所有钢材都适宜进行氮化。用普通碳钢进行氮化处理,钢的表面硬度提高不多,耐磨性、疲…     

离子氮化炉的阴极支承装置

众所周知，离子氮化具有渗氮速度快、渗层组织易于控制、热效率高、工件变形小、节约能源、脆性小、无公害污染、劳动条件好、防渗容易、在真空中处理工件不氧化、不脱碳，以及处理后的工件表面质量好等优点。经离子渗氮后的零件，表面硬度高，耐磨性好，且耐腐蚀性和疲劳强度也都有较大的提高，可用于解决摩擦条件下的许多问题，如磨损、疲劳、腐蚀和粘着等。     

新型涂层在高速钢钻头上的应用

本文研究了高速钢表面（TiAI)N涂层的组织结构及硬度和耐磨性，并在φ8mm钻头上进行切削应用试验，其结果表明经涂层处理后，提高了高速钢表面硬度和耐磨性，使钻头寿命成倍提高。     

Ti-V-MO系高硬度耐磨堆焊焊条

焊条药皮中采用石墨、钛铁、钒铁、钼铁等组分，通过电弧冶金反应生成具有高硬度的TiC、VC、MoC等碳化物颗粒，研制出具有硬度高、耐磨性好的耐磨堆焊焊条。探讨了焊条药皮中石墨、钛铁、钒铁、钼铁等组分含量对焊条工艺性及堆焊层硬度的影响。利用X射线衍射、光学显微镜（OM）和电子探针（EMPA）对堆焊层显微组织和碳化物形成进行了分析。研究结果表明，碳化物颗粒为TiC-VC-MoC复合碳化物颗粒，并且碳化物颗粒弥散分布在基体上。焊前不预热，焊后不缓冷连续堆焊不产生裂纹。堆焊层硬度达到HRC59以上，具有高的耐磨性，相对耐磨性优于D317焊条。     

基于TiC-VC的抗磨粒磨损堆焊焊条

用钛铁、钒铁、石墨、人造金红石等组成焊条药皮，通过高温电弧，台金反应生成TiC-VC，研制了硬度高、抗裂性好的耐磨粒磨损堆焊焊条。通过扫描电镜、工艺性能试验、磨粒磨损试验等，系统地研究了焊条药皮组分对堆焊层硬度、工艺性能、耐磨性及显微组织的影响。结果表明：随着药皮中钛铁、钒铁、石墨组分增加，堆焊层硬度提高，但焊接工艺性能恶化。堆焊层显微组织为低碳马氏体和碳化物。堆焊抗裂性优于D618、D667焊条，相对耐磨性可达D667焊条的8倍。     

碳纳米管镍基复合刷镀层的组织和性能

研究了碳纳米管镍基复合刷镀层的组织、显微硬度和耐磨性等。结果表明：与常规镀层相比，含有碳纳米管的复合镀层组织明显细化，显微硬度有较大的提高，硬度热稳定性和耐磨性得到了明显的提高。     

矿用液压支柱激光熔覆不锈钢涂层试验研究

为解决液压支架耐磨性和耐腐性问题,采用激光熔覆技术对液压支柱表面进行熔覆不锈钢涂层,并对激光熔覆液压支柱的硬度、耐磨性和耐腐性等性能进行了测试试验。测试显示,采用激光熔覆不锈钢涂层对液压支柱表面涂层后,液压支柱硬度、耐磨性和耐腐性显著提高。从而说明激光熔覆技术可改善液压支柱的性能,为矿井安全开采提供了技术支撑。     

电磁热处理在普通手用锯条热处理上的应用研究

在锯条热处理过程中，保温时通入一定强度的脉冲电流，放入顺磁场中冷却，处理后T10钢锯条锯齿表面硬度可达到HV825～889，锯身的塑性较普通热处理也有较大提高，高的锯齿硬度和耐磨性加上好的锯身塑性使锯条的使用寿命得以延长。     

高铬铸铁自保护堆焊药芯焊丝的研制

研制了一种新型高铬铸铁堆焊药芯焊丝,其单道单层堆焊室温硬度为HRC48左右,便于切削加工,焊道层金属具有良好的抗裂性。该焊丝的最大特点是堆焊时采用普通埋弧焊机,不需加入任何保护气体和焊剂即能顺利进行堆焊,节省了保护气体或焊剂,简化了操作过程。介绍了焊丝设计原理及堆焊层金属的有关性能。     

Comparison of the machinability and wear properties of magnesium alloys

AZ and AS series magnesium alloys were used in this study and had different contents (i.e., 0 to 9 wt.% Al). The effect of zinc (Zn) and silicon (Si) on wear resistance and machinability was analyzed in AZ and AS series magnesium alloys. Zn amount in AZ series (1 %) and Si amount in AS series (1 %) were kept at a fixed rate. The effect of the changes in Al amount on hardness, wear resistance, and machinability in AZ and AS series magnesium alloys was comparatively analyzed. A higher increase was observed in the wear resistance of alloys in AS series magnesium alloys due to the rise in Al amount compared with AZ series. Intermetallic phases found in the microstructure of alloys (β-Mg₁₇Al₁₂ and Mg₂Si) were established to have an impact on the wear resistance and machinability of alloys.     

Tool wear and surface quality in milling of a gamma-TiAl intermetallic

Advanced structural materials for high-temperature applications are often required in aerospace and automotive fields. Gamma titanium aluminides, intermetallic alloys that contain less than 60?wt.% of Ti, around 30–35 wt.% of aluminum, and other alloy elements, can be used as an alternative to more traditional materials for thermally and mechanically stressed components in aerospace and automotive engines, since they show an attractive combination of favorable strength-to-weight ratio, refractoriness, oxidation resistance, high elastic modulus, and strength retention at elevated temperatures, together with good creep resistance properties. Unfortunately such properties, along with high hardness and brittleness at room temperature, surface damage, and short and unpredictable tool life, undermine their machinability, so that gamma-TiAl are regarded as difficult to cut materials. A deeper knowledge of their machinability is therefore still required. In this context the paper presents the results of an experimental campaign aimed at investigating the machinability of a gamma titanium aluminide, of aeronautic interest, fabricated via electron beam melting and then thermally treated. Milling experiments have been conducted with varying cutting speed, feed, and lubrication conditions (dry, wet, and minimum quantity lubrication). The results are presented in terms of correlation between cutting parameters and lubrication condition with tool wear, surface hardness and roughness, and chip morphology. Tool life, surface roughness, and chirp morphology showed dependence on the cutting parameters. Lubrication conditions were observed to heavily affect tool wear, and minimum quantity lubrication was shown to be by far the method that allows to extend tool life.     

镍基高温合金高速切削加工性

镍基高温合金具有优良的高温强度以及良好的热稳定性和抗热疲劳性能,广泛应用于航空发动机、燃气涡轮机等领域。但其可加工性极差,切削过程中刀具迅速磨损,加工效率较低。本文介绍了镍基高温合金高速切削加工性的研究进展,重点阐述了适宜高速切削镍基高温合金的陶瓷和PCBN刀具及加工参数,并总结了切削过程中刀具的失效形式和磨损机理,以及利用辅助加工方法等实现陶瓷刀具对镍基高温合金精加工的可能性。为高速切削镍基高温合金加工刀具的快速选择及加工工艺的改进提供了参考。     

Friction and Wear Performance of Boron Doped,Undoped Microcrystalline and Fine Grained Composite Diamond Films

Chemical vapor deposition(CVD) diamond films have attracted more attentions due to their excellent mechanical properties. Whereas as-fabricated traditional diamond films in the previous studies don’t have enough adhesion or surface smoothness, which seriously impact their friction and wear performance, and thus limit their applications under extremely harsh conditions. A boron doped, undoped microcrystalline and fine grained composite diamond(BD-UM-FGCD) film is fabricated by a three-step method adopting hot filament CVD(HFCVD) method in the present study, presenting outstanding comprehensive performance, including the good adhesion between the substrate and the underlying boron doped diamond(BDD) layer, the extremely high hardness of the middle undoped microcrystalline diamond(UMCD) layer, as well as the low surface roughness and favorable polished convenience of the surface fine grained diamond(FGD) layer. The friction and wear behavior of this composite film sliding against low-carbon steel and silicon nitride balls are studied on a ball-on-plate rotational friction tester. Besides, its wear rate is further evaluated under a severer condition using an inner-hole polishing apparatus, with low-carbon steel wire as the counterpart. The test results show that the BD-UM-FGCD film performs very small friction coefficient and great friction behavior owing to its high surface smoothness, and meanwhile it also has excellent wear resistance because of the relatively high hardness of the surface FGD film and the extremely high hardness of the middle UMCD film. Moreover, under the industrial conditions for producing low-carbon steel wires, this composite film can sufficiently prolong the working lifetime of the drawing dies and improve their application effects. This research develops a novel composite diamond films owning great comprehensive properties, which have great potentials as protecting coatings on working surfaces of the wear-resistant and anti-frictional components.     

含钒高铬铸铁自保护金属芯堆焊焊丝的研制

研制了一种自保护金属芯堆焊药芯焊丝。堆焊过程飞溅小，焊缝成型美观。堆焊层组织为马氏体＋残余奥氏体＋碳化物硬质相。堆焊层硬度为HRC60，相对耐磨性为Q235钢的21倍。焊丝的熔滴过渡方式为典型的短路过渡。研究焊丝粉芯成分对焊丝的性能发现，石墨可以有效的降低飞溅，当粉芯中的石墨含量为3％时，堆焊过程中的飞溅率最低，此外增加粉芯中钒的含量，堆焊层的硬度和耐磨性上升。     

高抗裂耐磨堆焊焊条的研制

为开发高抗裂高耐磨的堆焊焊条,采用H08A焊芯,通过调整药皮中的组分,设计了4种碱性焊条,然后分别在Q235钢基体上进行堆焊,采用光谱仪、硬度计、光学显微镜、扫描电镜和能谱仪等对堆焊层的化学成分、硬度和显微组织进行了分析,并研究了堆焊层的耐磨性和抗裂性。结果表明:优化成分焊条的堆焊层组织为混合型马氏体+少量残余奥氏体+弥散分布的一次NbC-TiC颗粒,低碳马氏体和高碳马氏体数量相当,硬度为58.1 HRC;堆焊层具有高的抗裂性能,连续堆焊不产生宏观裂纹;堆焊层的耐磨性也较好,约为淬火态45钢的1.41倍。     

Prediction of cutting force, tool wear and surface roughness of Al6061/SiC composite for end milling operations using RSM

The results of mathematical modeling and the experimental investigation on the machinability of aluminium (Al6061) silicon carbide particulate (SiCp) metal matrix composite (MMC) during end milling process is analyzed. The machining was difficult to cut the material because of its hardness and wear resistance due to its abrasive nature of reinforcement element. The influence of machining parameters such as spindle speed, feed rate, depth of cut and nose radius on the cutting force has been investigated. The influence of the length of machining on the tool wear and the machining parameters on the surface finish criteria have been determined through the response surface methodology (RSM) prediction model. The prediction model is also used to determine the combined effect of machining parameters on the cutting force, tool wear and surface roughness. The results of the model were compared with the experimental results and found to be good agreement with them. The results of prediction model help in the selection of process parameters to reduce the cutting force, tool wear and surface roughness, which ensures quality of milling processes.     

采煤机滑靴等离子熔覆高铬铁基合金的摩擦学性能

采煤机导向滑靴工作环境恶劣,受力复杂,导致其经常因为磨损和开裂而失效。为提高采煤机导向滑靴耐磨性,采用等离子熔覆技术在调质45#钢基材表面熔覆一层高铬铁基合金,在保持基体良好的综合机械性能的情况下,得到具有高强度、高硬度、高耐磨、耐腐蚀的高铬铁基合金熔覆层,既节省了合金材料的使用,又满足了煤矿复杂条件下对采煤机滑靴材料性能的要求。高铬铁基合金熔覆层在高载下具有较低的摩擦因数,可降低设备运转时的能量耗损;抗黏着磨损和磨粒磨损能力较强,可提高滑靴的使用寿命。     

两种硬面药芯焊丝堆焊层金属耐磨性的研究

对研制的两种硬面药芯焊丝HDY704、HDY502焊态和焊后热处理堆焊层金属的显微组织及耐磨性能进行了研究,探讨了堆焊层金属的磨损机理。结果表明：合金钢硬面药芯焊丝HDY704和不锈钢硬面药芯焊丝HDY502堆焊层金属的显微组织均为马氏体加少量残余奥氏体;焊后热处理均能提高其耐磨性能;热处理后HDY502堆焊层金属有弥散碳化物析出使硬度增加近10HRC,而HDY704堆焊层金属的硬度不变;堆焊层金属的磨损机理为沙粒在压力作用下被压入基体中沿运动方向的切削破坏。