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为了提高钛合金表面的疏水性能,采用润湿理论模型与多物理场耦合仿真相结合的方法,建立接触角与掩膜电解加工工艺参数之间的直接映射关系,揭示微坑阵列掩膜电解加工对表面疏水性能的作用。建立接触角与微坑阵列几何尺寸间的表面疏水理论模型,对掩膜电解加工进行多物理场耦合仿真;理论模型与仿真结果相结合,获得了接触角与掩膜电解加工工艺参数之间的直接映射关系。此外,以表面接触角为因变量,以电解质质量分数、掩膜尺寸和电解电压为自变量,进行正交试验仿真和计算,获得了最佳工艺参数组合并进行试验验证。与仿真计算相比,试验测量得到的微坑阵列直径、间距、深度、表面接触角误差分别为2.49%、6.87%、7.40%、6.01%,从而表明该方法在未经低表面能材料修饰的情况下,成功制备接触角约为141°的微坑阵列疏水表面。 相似文献
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《中国腐蚀与防护学报》2018,(5)
利用定向电沉积技术在316L不锈钢表面设计制备了一种超疏水微纳镍镀层,通过对电沉积参数的优化,获得最佳电沉积工艺参数:初次电沉积电流密度5 A·dm~(-2),电沉积时间为480 s,结晶调节剂浓度为1.5 mol/L;二次电沉积条件为10 A·dm~(-2),60s。借助SEM、XRD、电化学测试技术、接触角测试对涂层进行表征,结果表明制备的316L不锈钢表面镍镀层阵列微纳结构具有典型的花瓣状分级结构和较好的超疏水性能,镍镀层阵列微纳结构由具有(110)择优取向晶面的针锥阵列结构组成,随着二次电沉积电流密度的增大,镍镀层阵列微纳结构的生长经历从针锥向花瓣结构转变。 相似文献
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目的 为了解决现有电解加工技术中难以使用同一装置在多种型面零件表面一次性大面积制备高精度微坑阵列的现状。方法 提出一种可用于多种型面零件批量加工微坑阵列的线阴极滚印式掩膜电解加工技术,设计了一种滚筒式掩膜复合线阴极的阴极工具装置,采用铜丝(直径500μm)作为阴极,图形化的聚氯乙烯(PVC)作为掩膜,在10%NaNO3电解液、0.1 mm极间间隙条件下,在不锈钢304材料工件表面进行电解微坑试验,探究电压、阴极工具旋转速度、阴极尺寸对加工微坑阵列形貌的影响,通过超景深显微镜、扫描电子显微镜以及奥林巴斯显微镜对电解后的工件试样表面进行表面微观形貌观测。结果 选用10.5 V的电压、0.2 r/min的旋转速度可在工件表面加工出高精度、高一致性的微坑阵列,其微坑直径分布范围为402.8~440.3μm,深度范围为66.2~74.2μm,微坑粗糙度范围为0.42~0.83μm。与传统的圆环型阴极电解加工结果对比,线阴极电解加工出的微坑阵列直径偏离掩膜孔尺寸小、定域性高。结论 使用线阴极滚印式掩膜电解加工方法可在不锈钢304材料工件平面、内圆柱面及外圆柱面制备大批量、高精... 相似文献
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目的提出一种在金属表面制备可控的微纳结构的方法,改善金属表面的疏水性。方法利用丝网印刷快速制备可控微细图案,电解加工快速加工出微细结构,化学氧化法制备出纳米结构,从而成功地在铜表面制备了具有微米纳米复合结构的超疏水表面。在此过程中,首先通过丝网印刷辅助电解加工制备有序微圆柱阵列,然后利用化学氧化在微圆柱表面制备纳米结构,通过扫描电子显微镜(SEM)和接触角来表征铜表面的超疏水性能,用质量变化法研究了铜表面的抗结霜性能。结果丝网印刷的圆形掩膜直径为140~160μm,电解加工后,圆柱直径为130~140μm,高度为15μm左右。SEM测试结果表明,用15wt%FeCl_3溶液进行蚀刻,在铜表面出现了圆柱阵列的微纳复合结构。用氟硅烷乙醇溶液改性微纳复合结构圆柱阵列铜表面时,最大接触角为155°,表现出超疏水性能。抗结霜测试表明,所测试的超疏水表面的抗结霜性能显著增强。结论印刷电解法可以制备出形状和尺寸可控的微结构,对微结构进一步处理可得到微纳复合结构。该结构可以构成超疏水表面,且具有抗结霜性能。 相似文献
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扫描喷射电沉积纳米晶铜的试验研究 总被引:2,自引:0,他引:2
对扫描喷射电沉积纳米晶铜的工艺特点和沉积层微观结构进行了研究。结果表明,扫描喷射电沉积的电流密度和沉积速度随电压的增大呈线性增大,可用电流密度和沉积速度远高于传统电沉积。电流密度、喷射流量和扫描速度都对沉积层的表面生长形态有较大的影响,使用低电流密度、高喷射流量和快扫描速度有利于获得平整、致密的沉积层,在较大的电流密度范围内可获得晶粒尺寸小于40nm的铜沉积层。电流密度由100A/dm^2增至300A/dm^2时,择优取向晶面由(220)晶面逐渐转变为(111)晶面。 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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B.W. Zhang B.W. Li 《金属学报(英文版)》2007,20(2):129-138
On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes' collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process. 相似文献
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R.Z. Wu Z.K. Qu B.D. Sun D. Shu J. Wang 《金属学报(英文版)》2007,20(3):193-198
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results. 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