PMMA表面高功率脉冲磁控溅射制备ITO涂层（英文）

采用高功率脉冲磁控溅射技术在PMMA基体上制备了ITO涂层。利用XRD、SEM对涂层进行了相结构的分析,并进行了划痕实验、光电性能测试。结果表明:偏压、氢氩流量比等工艺参数对涂层的相结构、膜基结合力、光电性能均有影响。增大偏压,膜基结合力将增强,偏压达到240 V时,膜基结合力最好(56.5 N)。偏压由0 V增加到160 V的过程中,涂层晶粒增大,透射率变高(由82.24%增至89.82%),电阻率变低(由0.006571减至0.000543?·cm)。当氢氩流量比由0增至0.05,透射率变低(由89.82%减至56.12%)。氢氩流量比由0增至0.03,电阻率变低(由0.000 543减至0.000 212?·cm);氢氩流量比由0.03增至0.05,电阻率变高由0.000 212增至0.000 373?·cm)。     

基体偏压对高功率脉冲磁控溅射制备CrAlN薄膜性能的影响

为了防止氢扩散导致金属材料的失效,通常在其表面制备一层CrN阻氢薄膜。但是CrN涂层的热稳定性较差,抗氧化温度低于600℃。采用高功率脉冲磁控溅射技术,利用Cr和Al双靶共沉积CrAlN薄膜来提高其高温抗氧化性能。试验变量为基体负偏压的大小,分别为-100 V、-200 V、-300 V和-400 V。结果表明,四组CrAlN薄膜均为柱状晶结构,随着基体偏压提高,膜层的致密度提高,但同时薄膜沉积速率下降;CrAlN薄膜的择优生长方向为Cr(200)晶面法线方向。四组CrAlN薄膜的氢抑制率均超过70%,氢原子扩散系数最低比316L不锈钢基体低3个数量级。当基体偏压为-300 V时,可以同时获得最优的氢抑制率(87.4%)和最低的氢原子扩散系数(6.188×10^-10 cm²/s)。600℃、氧气气氛下保温60 min,CrAlN膜基结合面处氧含量仅为表面处的30%左右。相比于CrN薄膜,在相同基体偏压下,CrAlN薄膜的氢原子扩散系数更小;高偏压下制备的CrAlN薄膜氧增重量仅为316L不锈钢基体的10%,抗氧化性能更好。     

ZL109铝合金表面多弧离子镀TiN薄膜的制备及性能

利用正交设计试验探讨了基体温度、偏压、溅射时间、沉积时间对ZL109表面沉积TiN涂层时,对薄膜显微硬度和膜/基结合力的影响.结果表明,在ZL109表面多弧离子镀制备TiN薄膜的最佳工艺为:基体温度260 ℃、偏压200 V、沉积时间30 min、溅射时间8 min、Ti靶电流80 A、炉内总压1 Pa(Ar和N_2流量比为1∶2).在此工艺下制备的TiN薄膜显微硬度达到1500 HV0.05,膜/基结合力达到36 N,膜厚约2～3 μm.     

弧离子镀TiAlN涂层与模具钢基材的结合力的优化

采用弧离子镀方法在SKD61模具钢基体上制备TiAIN薄膜,分析了工艺参数对膜层与模具钢基体结合力的影响.应用正交法.依据涂层与基体的临界载荷越大结合力越好的原则,得出了最优涂层的工艺参数:基体温度220℃、弧流60A、沉积基体偏压-800V、气体压强1.3 Pa、预处理基体偏压-450V和预处理时间15min.优化后的涂层与基体的临界载荷达到56 N,比优化前最大临界载荷增加43%.TiAIN薄膜与模具钢基体结合力的改进主要归功于涂层的高硬度和TiAIN相(111)、(200)和(220)取向的竞争生长.     

脉冲磁控溅射MoS2涂层的组织结构及摩擦学性能

采用单极性脉冲磁控溅射技术在A286基体表面制备MoS₂低摩擦系数涂层(LFC)。利用XRD、SEM等手段表征涂层的成分与微观组织;采用原位纳米力学测试系统、球-盘式摩擦磨损试验机分析涂层的力学和摩擦学性能,并探讨了脉冲偏压对涂层结构、力学和摩擦学性能的影响。结果表明,脉冲偏压由300V增加到600V,MoS₂涂层择优取向发生了(002)向(100)转变,当脉冲偏压增至800V时又恢复(002)择优取向,;随着脉冲偏压的增加,涂层的硬度及弹性模量出现先减少后增大趋势,摩擦系数在0.065~0.076范围内波动,呈现出先增加后减小趋势;偏压为800V的涂层摩擦学性能最佳,其磨损率仅为基体的13.5%。     

离子源预处理工艺对WC基底表面及Ta缓冲涂层的影响

研究了阳极层离子源预处理工艺对WC硬质合金基底表面粗糙度Ra和表面最大峰谷值Pv的影响,以及对后续镀制Ta缓冲涂层表面特征及膜基附着力的影响。结果表明,硬质合金基片表面粗糙度和表面最大峰谷值的增加量随基片偏压升高呈指数增加;而离子源电压对基片表面粗糙度和表面最大峰谷值影响较弱;采用离子源电压1350 V,基片偏压200 V轰击硬质合金基片15 min后镀制Ta膜,膜层表面晶粒细小均匀,表面致密性显著增加;此外,基片表面经离子源处理后,镀制的Ta缓冲层与基底的膜基结合力有较大改善,这将有利于提高后续贵金属保护涂层的附着力及抗元素扩散能力。     

氮含量对直流磁控溅射(TiAlTaCrZr)N涂层力学及钛合金切削性能影响研究

解决传统刀具耐磨涂层导热性差的问题。本文采用直流磁控溅射方法,在不同氮气流量下制备了(TiAlTaCrZr)N涂层,研究了不同氮含量对涂层微结构和硬度、结合力、导热等性能的影响。随着氮气流量的增加,涂层中N含量增加,涂层微观结构会由纳米晶向柱状晶转变。涂层的硬度从TiAlTaCrZr 涂层的11.0 GPa增加到5 SCCM氮流量时(TiAlTaCrZr)N 涂层的20.6 GPa。涂层在氮气流量为5 SCCM时膜基结合力可达到130 N以上,之后随着氮含量增加逐渐降低。(TiAlTaCrZr)N涂层的导热性均优于TiAlN涂层的导热性,但随着氮含量增加导热性降低。(TiAlTaCrZr)N涂层的高导热性、高结合力、高硬度等特性使其在钛合金高速切削时切削距离比TiAlN涂层提高175%,这为钛合金加工提供了一种新型耐磨涂层。     

沉积偏压对MoN涂层结构和柴油中摩擦学性能的影响

目的 研究沉积偏压对MoN涂层微观结构、性能,以及在柴油介质中摩擦学行为的影响机制。方法 采用磁控溅射技术在304不锈钢基体上沉积MoN涂层。利用X射线衍射仪、X射线光电子能谱仪、X射线能谱仪、原子力显微镜、纳米压痕仪、薄膜应力测试仪和电化学工作站研究MoN涂层的微观结构、成分、表面粗糙度、力学性能、耐腐蚀性能。利用球−盘式摩擦实验机和激光拉曼光谱仪对MoN涂层在0号柴油中的摩擦学行为及机制进行研究。结果 随着偏压的增加,涂层的厚度和膜−基结合力均呈先增大后减小的趋势;涂层的表面粗糙度、内应力和硬度呈先升高后降低的趋势。在偏压为−120 V时,沉积的γ-Mo2N涂层组织致密、表面光滑(Sa 7.78 nm)、硬度高(18.02 GPa)、膜−基结合力高(253 mN)。随着偏压的增加,涂层的摩擦因数呈先减小后增加的趋势。在偏压为−120 V时,沉积的γ-Mo2N涂层的摩擦因数和磨损率均最小,分别为0.10和1.8×10⁻⁷ mm³/(N∙m)。拉曼光谱分析结果表明,在摩擦催化作用下,柴油在磨痕表面产生了碳基膜。此外,通过电化学腐蚀分析发现,在偏压−120 V下沉积的γ-Mo2N涂层具有优异的耐腐蚀性能。结论 MoN涂层结构、性能受到偏压的影响显著。柴油在摩擦催化作用下发生了降解,形成了碳基膜,这有利于降低MoN涂层的摩擦因数和磨损率。     

电弧离子沉积钽膜及微结构研究

目的研究电弧离子沉积钽膜的沉积工艺及微观结构,分析钽膜生长机理。方法采用电弧离子沉积法在石墨基体上沉积钽膜,研究了沉积工艺(如弧电流、负偏压等参数)对钽膜的物相组成、沉积速率、表面形貌的影响。结果电弧离子沉积钽膜的物相由α-Ta相和极少量β-Ta相组成。弧电流、负偏压、靶间距等沉积参数对钽膜厚度、沉积速率和膜-基结合力的影响很大,在弧电流为220 A、负偏压为300 V、靶间距为200 mm时,钽膜沉积速率为0.1μm/min,沉积速率适宜,膜-基结合力达到69 N,结合力高。钽膜厚度均匀,在靠近基体侧形成了晶粒细小、组织致密的过渡层,厚度约0.6~0.9μm,其余为细小柱状晶结构。钽膜表面颗粒尺寸随负偏压的升高而减小,负偏压为300 V时,颗粒尺寸细小均匀(仅3~5μm),钽膜表面无细小孔隙和裂纹。结论电弧离子沉积法可以在石墨基体上沉积出组织致密、厚度均匀且膜-基结合力高的钽膜。沉积初期主要通过沉积、移动、扩散等过程形成稳定核,随着沉积时间的延长,稳定核逐渐长大成岛,并在三维方向以岛状生长形成连续膜,为典型岛状生长模式。     

同步脉冲偏压对Hi PIMS技术低温沉积CrN涂层结构及性能影响

针对高性能CrN涂层无法实现低温可控制备的技术瓶颈,利用具备高溅射材料离化率的高功率脉冲磁控溅射技术,调控同步脉冲偏压,改善涂层生长动力学条件,实现CrN涂层的低温可控沉积。开展同步脉冲偏压与涂层化学组成、组织结构、力学、摩擦学及耐腐蚀性能间关联关系研究。同步脉冲偏压在提升沉积离子束流迁移能的同时可显著降低荷能Ar+对成膜表面的持续轰击作用,达到改善涂层致密性及膜基结合力的目的。此外,沉积CrN涂层晶粒细化显著,硬度及弹性模量明显升高,最高可达13.8 GPa、236.7 GPa。涂层力学性能优化及致密性提升显著改善了摩擦学与耐腐蚀性能,涂层磨损率最低可达2.49×10^-15m³/(N·m),同时涂层可耐受120h中性盐雾腐蚀环境考核。为实现高性能CrN涂层的低温可控制备,扩展其在温度敏感基体领域的适用范围提供了新的设计思路与技术支撑。     

Refinement and strengthening mechanism of Mg−Zn−Cu−Zr−Ca alloy solidified under extremely high pressure

Mg?Zn?Cu?Zr?Ca samples were solidified under high pressures of 2–6 GPa. Scanning electron microscopy and electron backscatter diffraction were used to study the distribution of Ca in the microstructure and its effect on the solidification structure. The mechanical properties of the samples were investigated through compression tests. The results show that Ca is mostly dissolved in the matrix and the Mg₂Ca phase is formed under high pressure, but it is mainly segregated among dendrites under atmospheric pressure. The Mg₂Ca particles are effective heterogeneous nuclei of α-Mg crystals, which significantly increases the number of crystal nuclei and refines the solidification structure of the alloy, with the grain size reduced to 22 μm at 6 GPa. As no Ca segregating among the dendrites exists, more Zn is dissolved in the matrix. Consequently, the intergranular second phase changes from MgZn with a higher Zn/Mg ratio to Mg₇Zn₃ with a lower Zn/Mg ratio. The volume fraction of the intergranular second phase also increases to 22%. Owing to the combined strengthening of grain refinement, solid solution, and dispersion, the compression strength of the Mg–Zn–Cu–Zr–Ca alloy solidified under 6 GPa is up to 520 MPa.     

解决晶闸管装置互相干扰问题一例

如果晶闸管整流器负载是感性的，那么触发器的电流值是从零开始上升，而且电感量越大，电流上升越慢，可能造成触发脉冲过后因通导电流太小而截止或造成对电源的适应性降低。在设计中必须考虑晶闸管维持电流值和通导电流上升率的关系问题。     

采用挤压剪切工艺制备细晶高强韧镁合金

设计一种新型挤压剪切(ES)复合工艺以制备细晶高强韧镁合金.利用有限元软件Deform-3D,通过正交模拟实验对ES模具的结构参数进行优化,并采用ES模具对Mg?3Zn?0.6Ca?0.6Zr(ZXK310)合金进行成形.结果表明,优化的ES模具结构参数为挤压角ɑ=90°、挤压段高度h=15 mm以及内圆角半径r=10...     

铜捕集法从失效汽车催化剂中回收铂、钯和铑的研究

采用铜捕集法从失效汽车催化剂中回收铂族金属,重点研究了Ca O/Si O2质量比、捕集剂、熔炼温度和时间、以及还原剂对Pt、Pd和Rh回收率的影响。结果表明,在Ca O/Si O2=1.05,Cu O配比35%~40%,还原剂配比6%,熔炼温度1400℃,熔炼时间5 h的条件下,Pt、Pd和Rh回收率分别为98.2%、99.2%和97.6%。     

Hot deformation behaviors and dynamic recrystallization mechanism of Ti-35421 alloy in β single field

Hot deformation behaviors and microstructure evolution of Ti?3Al?5Mo?4Cr?2Zr?1Fe (Ti-35421) alloy in the β single field are investigated by isothermal compression tests on a Gleeble?3500 simulator at temperatures of 820?900 °C and strain rates of 0.001?1 s^?1. The research results show that discontinuous yield phenomenon and rheological softening are affected by the strain rates and deformation temperatures. The critical conditions for dynamic recrystallization and kinetic model of Ti-35421 alloy are determined, and the Arrhenius constitutive model is constructed. The rheological behaviors of Ti-35421 alloys above β phase transformation temperature are predicted by the constitutive model accurately. The EBSD analysis proves that the deformation softening is controlled by dynamic recovery and dynamic recrystallization. In addition, continuous dynamic recrystallization is determined during hot deformation, and the calculation model for recrystallization grain sizes is established. Good linear dependency between the experimental and simulated values of recrystallized grain sizes indicates that the present model can be used for the prediction of recrystallized grain size with high accuracy.     

Effect of yttrium and calcium additions on electrochemical behaviors and discharge performance of AZ80 anodes for Mg−air battery

The effects of yttrium (Y) and yttrium + calcium (Y+Ca) additions on the electrochemical properties and discharge performance of the as-extruded Mg?8Al?0.5Zn?0.2Mn (AZ80) anodes for Mg?air batteries were investigated. The results show that the addition of 0.2 wt.% Y increased the corrosion resistance and discharge activity of AZ80 anode. This was attributed to the fine and spherical β-Mg₁₇Al₁₂ phases dispersing evenly in AZ80+0.2Y alloy, which suppressed the localized corrosion and severe “chunk effect”, and facilitated the rapid activation of α-Mg. Combinative addition of 0.2 wt.% Y and 0.15 wt.% Ca generated grain refinement and a reduction of the β-Mg₁₇Al₁₂ phase, resulting in a further enhancement in discharge voltage. However, the incorporation of Ca in Mg₁₇Al₁₂ and Al₂Y compounds compromised the corrosion resistance and anodic efficiency of AZ80+0.2Y+0.15Ca anode. Consequently, AZ80+0.2Y anode exhibited excellent overall discharge performance, with the peak discharge capacity and anodic efficiency of 1525 mA·h·g^?1 and 67% at 80 mA/cm², 13% and 14% higher than those of AZ80 anode, respectively.     

NaCl溶液中AZ91D的腐蚀性能--RE与Sb及Si对AZ91D合金在NaCl溶液中腐蚀速率的影响

通过静态失重法研究了RE、Si和Sb元素加入后对AZ91D合金在NaCl溶液中腐蚀速率的影响.结果表明, RE加入可以提高AZ91D合金的腐蚀速率,而Si和Sb的加入使合金的腐蚀速率加大.     

Effects of annealing at 800 and 1000 °C on phase precipitates and hardness of Al7Cr20FexNi73−x alloys

The effects of Fe content on the microstructure, phase constituents and microhardness of the as-cast, 800 °C- or 1000 °C-annealed Al₇Cr₂₀Fe_xNi_73?x (x=13?66) alloys were investigated. Not all these alloys are composed of the single FCC phase. The BCC and B2 phases are found. It is confirmed that the BCC phase in the Al₇Cr₂₀Fe₆₆Ni₇ alloy is transformed from the FCC phase at about 900 °C during cooling. While in the 800 °C-annealed Al₇Cr₂₀Fe₆₀Ni₁₃ alloy, the FCC phase is stable and the hardness decreases. After annealing at 1000 °C, for the precipitation of the B2 particles, the Al content in the FCC phase decreases, which results in decreasing of the alloy hardness. Moreover, after annealing at 800 °C, a small amount of Al-rich B2 particles precipitate at the phase boundary and some nanocrystal BCC phase precipitates in the FCC matrix, which increases the hardness of the Al₇Cr₂₀Fe_xNi_73?x (x=41?49) alloys. These results will help to the composition design and processing design of the Al?Cr?Fe?Ni based high-entropy alloys.     

固溶时效对TC21钛合金准β锻后组织性能的影响

对TC21钛合金进行准β锻造,再进行固溶时效热处理实验,研究了不同固溶时效热处理制度对合金的微观组织和力学性能的影响。结果表明,TC21钛合金通过准β锻造后,再经固溶时效热处理工艺处理后,合金的微观组织呈现典型的网篮组织。随着固溶温度的上升,片状α相含量和长度显著降低,同时合金强度增加,而塑性变化呈相反趋势。随着时效温度的上升,对片状α相的影响略小,但次生α相的厚度此时显著增加,此时合金强度降低,塑性提高。断口形貌则随着固溶温度的升高,断口表面和裂纹扩展路径愈发平坦。断裂韧性值呈现下降趋势,但会随着时效温度的升高而提高。合金最大断裂韧性值可达66MPa·m1/2。考虑合金的强度、塑性和断裂韧性之间的良好匹配,经综合分析可得,TC21钛合金准β锻后最佳热处理制度为:870 ℃/2 h,AC+590 ℃/4 h,AC。     

固溶加热速率与Al−Mg−Si−Cu合金力学性能、显微组织及织构的关系

通过拉伸试验、扫描电镜、X射线衍射仪和EBSD技术研究固溶加热速率与Al?Mg?Si?Cu合金力学性能、显微组织及织构的关系.实验结果表明,固溶加热速率与力学性能、显微组织及织构的关系是非单调的.随着加热速率的增加,强度变化取决于拉伸方向;加工硬化指数n先减小,后增加;塑性应变比r值先增加,后减小,最后又增加.加热速率...