CrAISiN涂层与不同材料配副时的摩擦学特性

目的 研究CrAlSiN涂层分别与304不锈钢、TC4钛合金、Al2O3陶瓷和GCr15钢四种不同材料配副时的摩擦学特性.方法 采用阴极电弧离子镀技术在M35高速钢上制备了CrAlSiN涂层,采用扫描电镜(SEM)、显微硬度计、划痕仪、球-盘式摩擦磨损试验仪和3D轮廓仪分别测试了涂层的结构和性能.结果 CrAlSiN涂层与304不锈钢、TC4钛合金和GCr15钢配副时的磨损形式为粘着磨损和磨粒磨损,其中与亲和性高的304不锈钢、TC4钛合金粘着磨损严重.CrAlSiN涂层与不锈钢对磨时,摩擦系数最高,达到0.71;与GCr15钢对磨时,摩擦系数最低,但摩擦系数波动大;与钛合金对磨时,摩擦系数介于两者之间.CrAlSiN涂层与亲和性较差的Al2O3陶瓷之间的磨损形式为磨粒磨损,随着磨损的进行,摩擦系数逐渐降低.结论 CrAlSiN涂层与亲和性较高的材料对磨时,磨损形式为粘着磨损和磨粒磨损,与亲和性较差的Al2O3对磨时为磨粒磨损.     

Influence of TiB2 addition on friction and wear behaviour of Al2024-TiB2 ex-situ composites

Present work encapsulated the friction and wear behaviour of aluminium matrix composites reinforced with different mass fractions of titanium diboride (TiB₂) particles, synthesized by stir casting. A pin on disc tribotester was employed for conducting the dry sliding wear tests of Al2024-TiB₂ composites. The tests were performed adopting various parameters like load, sliding distance and sliding velocity for investigating the effect of tribological parameters on the prepared composites. Microstructural characterization confirmed uniform dispersion of TiB₂ particles and good matrix-reinforcement bonding. Results of the experiments revealed that, low friction and wear rates were observed in the developed composites compared to Al2024 alloy, whereas wear rates of both Al2024 alloy and fabricated composites increased with the increase in load, sliding velocity and sliding distance. However, friction coefficient of both Al2024 alloy and fabricated composites reduced with the increase in applied load but rose with the increase in sliding velocity and sliding distance. SEM studies of the worn surfaces and debris depicted that enhancement in wear resistance can be ascribed to finer debris formation.     

钛合金表面辉光离子渗Mo合金化层在航空煤油环境中的摩擦学行为(英文)

为改善钛合金在航空煤油中的摩擦学性能,采用辉光离子渗技术在Ti6Al4V合金表面制备Mo合金化层。分析合金化层的表面形貌和微观结构,测试合金化层的显微硬度和元素沿层深的分布,对比研究钛合金基体、渗Mo合金化层和5CrMnMo工具钢在航空煤油中分别与GCr15钢及QSn4-3铜合金配副对磨时的耐磨性能,并探讨渗Mo合金化层的表面粗糙度对摩擦磨损行为的影响。结果表明:经表面抛光处理后,钛合金表面辉光离子渗Mo合金化层不仅显著降低了钛合金的摩擦因数,而且有效增强了摩擦配副的耐磨性。渗Mo合金化层的摩擦性能优于5CrMnMo工具钢。实验还发现铜合金配副的磨损体积损失与Mo合金化层的表面粗糙度成正比,这主要是由合金化层与配副表面之间微凸体的磨粒磨损作用决定的。     

OXIDATION OF PM ALLOY Al-10Ti DURING SLIDING WEAR

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Dry sliding wear of MA/PM Al-10Ti alloy

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速度和压力对SiCp增强铝基复合材料摩擦磨损性能的影响

研究了颗粒增强铝基复合材料及其基体的摩擦磨损性能。基体和复合材料的耐磨性有明显差异，复合材料的主要磨损形式是磨粒磨损，基体材料的主要磨损形式是粘着磨损。复合材料具有低的磨损率和稳定的摩擦因数，因此具有良好的耐磨性。     

Cr3C2/Ni3Al复合材料的微观组织和室温耐磨性

采用药芯焊丝法制得Ni-Al-Cr3C2复合焊丝,将该焊丝堆焊于工件表面,在堆焊过程中,利用氩弧物理热和Ni-Al反应热,Ni与Al化合反应生成Ni3Al金属间化合物,Cr3C2则发生分解,除少部分[C]与[Cr]固溶于Ni3Al基体中外,大部分反应重新析出细小的Cr3C2相,均匀地分布于Ni3Al基体中.室温磨粒磨损和微动磨损实验结果表明,Cr3C2/Ni3Al复合材料的耐磨性为Stellite12合金的2倍左右,较高的硬度、高的碳化物体积分数以及碳化物与Ni3Al基体间良好的界面结合力是Cr3C2/Ni3Al复合材料耐磨性优良的主要原因.     

Low stress abrasive wear behavior of a hardfaced steel

A plain carbon steel was overlayed with a wear-resistant hardfacing alloy by manual arc welding. Low stress abrasive wear tests were conducted with an ASTM rubber wheel abrasion tester using crushed silica and as the abrasive medium. The wear rate decreased with sliding distance, and there was an overall improvement in the abrasive wear resistance as a result of overlaying. The wear behavior of the samples has been discussed in terms of microstructural features while the examination of wear surface and subsurface regions provides insight into the wear mechanisms.     

AISI 316不锈钢和Ti6Al4V合金在海水环境中的腐蚀与腐蚀磨损行为(英文)

采用立式万能销盘腐蚀磨损试验机研究AISI 316不锈钢和Ti6Al4V合金在海水中与Al2O3陶瓷对磨时的腐蚀与腐蚀磨损行为,重点讨论腐蚀磨损之间的交互作用。结果表明,摩擦作用使得Ti6Al4V合金和316不锈钢的开路电位大幅下降,腐蚀磨损过程中的电流密度远高于静态腐蚀时的电流密度,摩擦明显促进了合金的腐蚀。两种合金在海水中的磨损量远大于在纯水中的磨损量,腐蚀促进了磨损,并且Ti6Al4V合金的耐磨性优于316不锈钢的耐磨性,腐蚀磨损之间的交互作用是材料损失的一个重要因素。本实验所用的摩擦装置为单向滑动的面面接触方式,这使得摩擦对腐蚀的促进作用在总磨损量中所占的比例很小。     

镀Zn钢-6016铝合金异种金属的激光熔钎焊及数值模拟

熔钎焊是抑制或减少钢/铝异种金属激光焊接过程中FeAl脆性金属间化合物产生的有效工艺方法。采用光纤激光器,不添加任何钎料,对1.2 mm厚DC56D+ZF镀锌钢和6016铝合金平板试件进行激光搭接焊试验,利用MATLAB软件,针对焊接过程的实际情况,在一定的基本假设下建立准稳态下钢/铝异种金属激光焊接熔池形状的数学模型,基于准稳态形状控制方程数值计算获得的熔池几何形状分布,结合试验来调整焊接工艺参数,获得最佳焊接成形,利用卧式金相显微镜、扫描电镜和X射线衍射仪等手段研究焊接接头各区域的金相组织、主要元素分布与物相组成。结果表明:焊接激光束照射搭接在钢板上的铝板对接焊缝时,焊接功率和焊接速度对熔池几何形状的影响较大,随着激光功率的增大,熔深增加;而随着焊接速度的增加,熔深却变浅。当焊接功率为1 600~1 800 W、焊接速度v=30 mm/s、离焦量D=0 mm时,焊缝成形性良好,无明显裂纹、气孔等缺陷,焊接接头区域存在一个台阶状结构,在平台区域,钢/铝两钟金属存在明显的界限,界面结合依靠液态的铝在钢母材表面上的润湿、填充和铺展等作用;下凹区域,钢/铝熔合较好,Fe和Al元素的混合区宽度较大,未形成明显的FeAl脆性金属间化合物,Fe和Al的热扩散是该区域界面结合的主要原因。     

Cold spray deposition of a WC-25Co cermet onto Al7075-T6 and carbon steel substrates

This work focussed on the deposition of wear-resistant and corrosion-resistant WC-25Co cermet powders on carbon steel and aluminium (Al7075-T6) substrates by cold gas spraying (CGS). The unique combination of mechanical, physical and chemical properties of WC-Co cermets has led to their widespread use for the manufacture of wear-resistant parts. X-ray diffraction tests were run on the powder and coatings to determine possible phase changes during the spraying process. The bonding strength of the coatings was measured by adhesion tests (ASTM C633-08). The sliding (ASTM G99-04) and abrasive (ASTM G65-00) wear resistance of the coatings were also studied. Corrosion resistance was determined by electrochemical measurements and salt fog spray tests (ASTM B117-03). CGS achieved thick, dense and hard WC-25Co coatings on both aluminium alloy Al7075-T6 and carbon steel substrates, with excellent tribological and electrochemical properties. We thus conclude that this method is very competitive compared with conventional thermal spraying techniques, giving thick, dense and hard coatings on both aluminium alloy Al7075-T6 and carbon steel substrates, with excellent tribological and electrochemical properties.     

Ti6Al4V合金干滑动磨损过程中摩擦层及摩擦氧化物的作用

目的分析Ti6Al4V合金在不同滑动速度下的干滑动磨损行为及磨损特征,研究钛合金的磨损机理,并探讨干滑动磨损过程中摩擦层及摩擦氧化物的作用。方法采用销盘式摩擦磨损试验机,对Ti6Al4V合金在不同滑动速度下进行干滑动磨损实验。采用磨损率和摩擦系数表征钛合金的磨损行为,采用SEM、EDS及XRD分析磨损表面及摩擦层的形貌及成分,采用数字显微硬度仪表征摩擦层的力学性能。结果滑动速度在0.5～4 m/s范围内变化,Ti6Al4V合金的磨损率发生显著变化,尤其是在高载条件下。0.5～1.5 m/s速度范围内,磨损率较低,2.68m/s速度下,磨损率达到最高值,4m/s速度下,磨损率达到最低值。0.75m/s速度下,粘着磨损和磨粒磨损为主要磨损机理,氧化磨损为次要磨损机理;2.68 m/s和4 m/s速度下的磨损机理分别为剥层磨损和氧化轻微磨损。2.68m/s速度下的高磨损率与硬度较低的无氧化物摩擦层对应,而4 m/s速度下的低磨损率与高硬度的多氧化物摩擦层对应。结论试验条件改变,Ti6Al4V合金的磨损行为及磨损机理发生变化。不同试验条件下的磨损行为与不同的摩擦层特征相对应,当摩擦层中包含一定量的摩擦氧化物时,这种陶瓷性的摩擦层具有比基体更高的硬度,能有效保护基体,降低磨损率。     

Research of the Tribological Properties of the Surface on 16Mn Steel by Plasma Nitriding and S-N-C Plasmas Composite Treatment

Sulfide layer with certain thickness was made on the nitrided surface of 16Mn steel by means of plasma S-C-N composite treatment. Under half lubricated condition, friction coefficient and wear loss of LY12 aluminum alloy were measured in sliding against samples of 16Mn treated by cubrizing and sulphiding respectively; In order to avoid the transfer of aluminum to the steel that lead to the inaccurate measurement of wear loss of carburized samples, Grl5 steel was adopted as counterpart face to measure the wear loss of them. SEM and EDAX were used for the morphological and chemical characterization of the wear surface and longitudinal cross-sections beneath sliding surface of LY12 aluminum alloy cirque and the wear tacks of the carburized samples and sulphided samples. Results show: The surface roughness,wear rate, average friction coefficient and magnitude of friction fluctuations of LY12 aluminum alloy cirque sliding against sulphided sample were all lower than sliding against carburized sample; Compared with carburized layer, sulfide layer of 16Mn steel can not only efficiently prevent the occurrence of adhesion when sliding against LY12 aluminum alloy, but also greatly lower the wear loss when sliding against Gr15 steel.     

氧乙炔火焰喷焊制备自熔性合金涂层及其性能研究

目的研究镍基自熔性合金喷焊涂层成形机理,比较不同合金材料制备涂层的综合性能,以获得综合性能最佳的喷焊材料。方法以四种不同成分的镍基自熔性合金粉末作为喷焊材料,通过氧乙炔火焰在45钢基材表面进行喷焊。使用金相显微镜、X射线衍射、扫描电子显微镜等对喷焊层进行显微结构分析,并利用维氏硬度计、磨损试验机等对喷焊涂层性能进行对比分析。结果氧乙炔火焰制备的涂层与基体呈现良好的冶金结合,涂层和基体在喷焊过程中发生元素扩散,生成了金属间化合物,基体的整体性能有显著改善。随着材料中Cr、B、Si等合金元素含量的增加,喷焊时涂层中生成的BCr、Ni17Si3等共晶硬质相含量上升,促使涂层的显微硬度、耐磨性能等得到显著提升。其中,Ni60A涂层提升最为显著,其涂层硬度相当于基体硬度的2.5倍,耐磨性为基体的18.1倍。Ni25A涂层提升最小,其显微硬度是基体的1.3倍,耐磨性是基体的6.6倍。结论喷焊状态下的Ni60A涂层与基体冶金结合良好,涂层表面质量好,涂层性能最佳。     

铬铁原矿粉掺杂制备CrFeNiSiAl0.5高熵合金涂层及其组织性能

目的 以40Cr钢为基体,制备掺杂铬铁原矿粉的CrFeNiSiAl0.5高熵合金涂层,提高其硬度与耐磨性.方法 在Cr、Fe、Ni、Al、Si纯金属粉末中掺杂铬铁原矿粉,矿粉有效原子数分数为0％、5％、10％、15％时,采用激光熔覆技术,在40Cr钢基体上制备CrFeNiSiAl0.5高熵合金涂层.利用X射线衍射仪、金相显微镜、扫描电子显微镜,表征高熵合金涂层的物相结构及微观组织.利用硬度计、磨粒磨损机,对涂层的硬度及耐磨性能进行表征.结果 不含铬铁原矿粉时,高熵合金涂层为单一的BCC相,铬铁原矿粉为10％时,出现FCC相.高熵合金涂层微观组织以胞状树枝晶为主,涂层与结合区存在明显分界,与基体呈良好的冶金结合.不含铬铁原矿粉时,高熵合金涂层平均硬度值为643.5HV;铬铁原矿粉为15％时,涂层平均硬度值为838.1HV,是基体的3.4倍.磨损率随铬铁原矿粉占比的增加而降低,铬铁原矿粉有效原子数分数为15％时,磨损率约为0.14 mg/mm2,耐磨性能最好.结论 在40Cr钢基体上成功制备出了以铬铁原矿粉为掺杂组元的高熵合金涂层,铬铁原矿粉的掺入,提升了CrFeNiSiAl0.5高熵合金涂层的硬度与耐磨性.     

Al/45钢高频感应钎焊焊料的研制

通过对Al/45钢焊料中钎料和钎剂理论要求的研究,选择出有利于钎焊的钎料合金体系、钎剂及粘结剂;然后通过润湿性和溶蚀性试验对不同配比焊料性能作出分析,研制出最有利于Al/45钢高频感应钎焊的一种焊料,试验结果表明:用此种焊料进行的Al/45钢高频感应钎焊,其钎焊结合面钎料润湿效果良好,界面没有发现裂纹等微观缺陷,显微组织大多为等轴晶,可形成牢固的Al/45钢焊接接头.     

对磨材料对TC11合金高温磨损行为的影响

采用高温磨损试验机对TC11合金在400、500、600℃进行磨损试验,研究对磨材料GCr15和M2钢对TC11合金的磨损行为的影响。结果表明,TC11合金无论与GCr15还是M2钢对磨,磨损率均随温度的升高而降低,TC11合金表现出优异的高温耐磨性。在大多数情况下,TC11合金磨损率随载荷增加均处于较低值且波动较小,但在400℃、超过200 N(与GCr15钢对磨)时和在400、500℃,大于200 N(与M2钢对磨)时磨损率显著增加。与M2钢对磨比与GCr15钢对磨使TC11合金磨损率升高。TC11合金的高耐磨性归因于摩擦氧化物层的保护作用。硬的对磨材料(M2钢)比软的对磨材料(GCr15钢)易于破坏TC11合金表面摩擦氧化物层而损害其保护作用。     

Microstructure and dry sliding wear resistance of CoTi intermetallic alloy

A wear resistant CoTi intermetallic alloy was fabricated by the laser melting deposition process. Microstructure of the alloy was characterized by OM, SEM, XRD and EDS and wear property was evaluated under room-temperature dry sliding wear test condition. Wear resistance of the CoTi intermetallic alloy under dry sliding wear test condition is up to 2 and 3.3 times higher than the hardened high-speed steel W18Cr4V and the bearing steel 1.0%C–1.5%Cr, respectively. The excellent wear resistance of the CoTi alloy is attributed to the inherent good toughness and strong yield-anomaly of the intermetallic CoTi as well as to the unique strong friction-induced hardening in the worn surface and subsurface of CoTi alloy under dry sliding wear process.     

Study On the Tribological Behavior of the Arc-added Glow Discharge Plasma Non-hydrogen Carburization On Titanium Alloy Surfaces

This paper introduces a new titanium alloys surface strengthening treatment by using the arc-added glow discharge plasmas non-hydrogen carburization technique. High purity and high strength graphite is selected as cooling cathode arc source for supplying carbon atoms and particle, which migrate to the titanium alloy(Ti6Al4V) surface and form modified layer. Thus, the hydrogen embrittlement is avoided while the tfibological behavior of the titanium alloy surface is improved in the respects of anti-friction and anti-wear ability.The tribological behavior of the modified layer under dry sliding against SAE52100 steel was evaluated on a ball-on-disc test rig. The results showed that the modified layer obtained a thickness of 30μm at 980℃, 30minutes. The microhardness of the Ti6Al4V alloy surface attained 936 HV, which was much larger than that of the Ti6AI4V alloy. The Ti6AI4V alloy was characterized by adhesion wear and scuffing under dry sliding against the steel, while the surface modified layer experienced much abated adhesion wear and scuffing under the same testing condition. This could be attributed to the carbon dement with different modalities exists in the modified layer.The modified layer showed good friction-reducing and fair anti-wear ability in dry sliding against the steel. Using the SEM,XRD and XPS, the phase structure and morphology of the carburization modified layer was analyzed.     

16Mn钢离子渗氮和离子 S-C-N共渗表面摩擦学性能

16Mn钢在离子渗氮基础上采用S-C-N的离子共渗技术制备出一层硫化物层，在半润滑条件下，以LY12铝合金圆环为对摩下试样，分别与16Mn钢表面渗碳和渗硫试样进行对摩试验；采用了GCr15钢为对摩下试样来测定16Mn钢表面渗碳和渗硫试样的磨损规律：用扫描电子显微镜，EDAX和XRD对磨损试样的磨痕形貌及成分做了分析。结果表明：与渗硫试样对摩的LY12铝合金圆环的表面粗糙度、磨损率、平均摩擦系数以及摩擦系数波动的幅度都比与渗碳试样对摩的要低；与LY12铝合金对摩过程中，渗硫层能够有效地避免粘着磨损，并且GCr15钢对摩过程中，渗硫层能够有效地降低16Mn钢的磨损程度。