共查询到20条相似文献,搜索用时 109 毫秒
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针对摩擦磨损引起的材料失效和机械设备损坏状况,基于原位摩擦化学处理技术研制了一种抗磨、减摩和润滑性能优异的摩擦处理剂.采用四球式摩擦磨损试验机和球-盘式高温摩擦磨损试验机设计了摩擦化学处理试验,通过改变加载负荷、温度、摩擦副材质和摩擦副之间的接触形式等试验参数考察了摩擦处理剂的抗磨减摩性能,采用SEM、EDS和XPS分析了摩擦处理剂的摩擦化学作用机理.结果表明在摩擦过程中,摩擦处理剂在金属表面原位形成了含MoS2、FeS和FePO4等减摩润滑效果良好的摩擦化学反应膜,从而显著的改善了金属材料的摩擦学性能,其抗磨性能和减摩性能分别较普通油提高了38%和46%. 相似文献
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《特种铸造及有色合金》2020,(5)
制备了不同Cu含量的球墨铸铁,采用拉伸试验机和布氏硬度计对球墨铸铁进行力学性能测试,采用往复摩擦磨损试验仪进行干摩擦试验,通过金相显微镜和扫描电镜对试样的微观结构进行表征,并探讨了Cu对球墨铸铁耐磨性能的影响。结果表明:Cu能有效提高球墨铸铁的耐磨性能。磨损机制以塑性变形为主,随着珠光体含量增加,磨粒磨损加剧。随着摩擦时间延长,疲劳磨损加剧;随着载荷增大,摩擦因数减小。 相似文献
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采用常规粉末冶金方法制备无铅含铋铜-钢双金属轴承材料,在HDM-20端面摩擦磨损试验机上进行边界润滑条件下的摩擦磨损试验,分析无铅含铋铜-钢双金属轴承材料的减摩、抗粘着性能及其承载能力,并与典型的铜铅轴承材料(Cu10Sn10Pb)及铜锡合金材料的性能进行对比.结果表明:无铅含铋铜轴承材料中的低熔点组元铋(熔点为271℃)能阻碍因油膜破裂而引起的摩擦副局部区域的直接接触,体现出较好的减摩和抗粘着性能;当铋含量为3.0%(质量分数)时,无铅含铋铜基轴承材料的减摩,抗粘着咬合性能良好,承载能力较强,接近或优于典型铜铅轴承材料的性能. 相似文献
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采用激光合金化技术在球墨铸铁QT600-3表面制备镍基合金强化层,通过XRD、SEM和摩擦磨损试验等研究了不同激光扫描速率对合金化层物相、微观结构、力学性能、常温和高温摩擦学性能的影响,并使用Raman光谱仪对磨痕进行分析。结果表明:Ni合金化层与基体冶金结合好、显微硬度高(高达720 HV0.1)、高温摩擦因数低至0.305、高温磨损率低至7.55×10-6 g·N-1·m-1。随着扫描速率的增加,显微组织更加致密,显微硬度先升高后降低,700 ℃耐磨性能提高,但合金化层裂纹率增加。高温摩擦磨损过程中,合金化层的磨损机制以磨粒磨损为主,同时还存在疲劳磨损和氧化磨损。同时,扫描速率的增加可细化晶粒和提高显微硬度。而Ni合金化层表面在高温摩擦过程中形成的氧化产物和碳化物在高温下会对提高其耐磨性能产生积极作用。 相似文献
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为降低球墨铸铁激光熔覆过程中白口组织的含量,改善其高温摩擦学性能和耐腐蚀性能,采用激光熔覆技术,通过添加Ni基过渡层在球墨铸铁表面制备Co基涂层。利用XRD、SEM、EDS表征不同熔覆层的物相组成、微观结构。采用高温摩擦磨损试验机测试不同温度下Co基涂层与球墨铸铁的摩擦磨损性能,分析Co基涂层在不同温度下的磨损机理。利用电化学工作站测试Co基涂层与球墨铸铁的耐腐蚀性能。结果表明:Ni基过渡层的物相为γ-Ni固溶体和Ni3Si陶瓷相。Co基涂层主要由γ-Co固溶体和Cr7C3陶瓷相构成。Ni基过渡层的添加抑制了基材中C元素扩散,降低了结合界面处白口化趋势。由于Cr7C3陶瓷相的强化作用,Co基涂层的显微硬度为球墨铸铁基材的2.1倍。与球墨铸铁基材相比,当温度高于200℃时,Co基涂层在与Si3N4配副对磨时表现出较低的平均摩擦因数与磨损率。在中低温条件下Co基涂层与Si3N4配副对磨时的磨损机制为黏着磨损与磨粒磨损,高温条件下的磨损机制为形成连续光滑的氧化层起到减摩抗磨的作用。C... 相似文献
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为了提高TC4钛合金表面硬度和耐磨性能,通过等离子渗氮技术和多弧离子镀技术相结合的方法对TC4钛合金进行表面改性处理。通过扫描电镜、维氏显微硬度计、三维轮廓仪、高速往复摩擦磨损试验仪和电化学工作站,对比研究了TC4钛合金、渗氮层和CrAlSiN涂层的显微组织、硬度、耐磨性能和耐腐蚀性能。结果表明,经渗氮处理后,TC4合金表面渗氮层硬度提高了约2倍,在此基础上制备的CrAlSiN涂层的平均硬度高达3222 HV0.025,涂层表面存在少许大颗粒和凹坑;CrAlSiN涂层平均摩擦因数为0.22,磨损机理主要为粘着磨损,对磨副的材料粘着到涂层表面,而涂层几乎无磨损,耐磨性能显著提高。CrAlSiN涂层的自腐蚀电位为-0.542 V,比TC4钛合金基体的自腐蚀电位-0.747 V正移了0.205 V,表明在渗氮层基础上沉积CrAlSiN涂层显著提高了合金的耐电化学腐蚀性能。 相似文献
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Deng-Kui Zhang Guo-Qing Wang Ai-Ping Wu Ji-Guo Shan Yue Zhao Tian-Yi Zhao Dan-Yang Meng Jian-Ling Song Zhong-Ping Zhang 《金属学报(英文版)》2019,32(6):684-694
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone. 相似文献
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After nearly two years'tense construction the first phase of industrialized base of Shenyang Research Institute of Foundry 《中国铸造》2008,5(1):63-64
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation. 相似文献
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Z. Sun S.L. Zheng Y. Zhang 《金属学报(英文版)》2007,20(3):187-192
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process. 相似文献
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R. González-Martínez 《金属学报(英文版)》2007,20(4):235-240
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke. 相似文献
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The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C). 相似文献
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The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel. 相似文献
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This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before. 相似文献
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Chao Yang He-Fei Huang Massey de los Reyes Long Yan Xing-Tai Zhou Tian Xia De-Liang Zhang 《金属学报(英文版)》2015,28(7):809
Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties. 相似文献
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Lei Li Bo Xu Wei-Ping Tong Hui Zhang Chun-Yan Ban Li-Zi He Zhi-Hao Zhao Yu-Bo Zuo Qing-Feng Zhu Jian-Zhong Cui 《金属学报(英文版)》2015,28(6):725
A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed. 相似文献
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综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。 相似文献