酸浸+等离子体刻蚀YG6微米-纳米金刚石复合涂层工具研究

金刚石涂层工具一直是金刚石膜工具应用研究的主流.制约其产业化的主要因素是涂层的附着力低和微晶金刚石涂层工具的加工精度差.通过对衬底的有效预处理和CVD沉积过程控制的研究,开发在硬质合金基体上沉积高结合强度、低粗糙度的金刚石涂层新技术,对于实现CVD金刚石涂层刀具高效、高精度切削加工具有重要意义.对旨在提高金刚石涂层附着力的预处理技术,本文探索了将酸蚀脱钴+等离子体刻蚀处理衬底法.利用优化的沉积工艺,在酸浸+等离子刻蚀处理的YG6刀片上沉积的两层金刚石复合膜表面粗糙度为0.13μm,附着力压痕测试临界载荷大于1500N.金刚石涂层工具的切削加工性能明显高于无涂层硬质合金工具.在加工ZAlSi12合金时,单层和两层金刚石涂层车刀片的切削寿命分别是无涂层车刀片切削寿命的21倍和28倍.     

两种预处理对硬质合金金刚石涂层附着力的影响对比研究

制约金刚石薄膜涂层工具走向市场化的关键问题是金刚石薄膜与硬质合金衬底的附着力低。困难来自于硬质合金的粘结相钴。消除钴对涂层附着力不利影响的措施很多。其中 ,真空渗硼和施加铜过渡层处理是两种较为有效的方法。本实验的目的就是要比较两种预处理对金刚石涂层附着力的影响。我们利用强电流直流伸展电弧等离子体CVD设备对真空渗硼和施加铜过渡层处理的刀片同时进行了金刚石薄膜沉积。通过激光喇曼、压痕和切削实验对其涂层的附着力进行分析、对比。结果表明 ,真空渗硼和施加铜过渡层处理均可有效地提高硬质合金金刚石涂层的附着力(未处理试样涂层的附着力 <60 0N。施加铜过渡层处理试样附着力 <15 0 0N ,真空渗硼预处理试样附着力≥ 15 0 0N)。但两者相比较而言 ,真空渗硼预处理法具有更好的效果     

渗硼+两步处理硬质合金微米-纳米金刚石复合涂层工具研究

研究了固体粉末渗硼＋碱酸两步预处理硬质合金基体的表面组织、形貌、粗糙度。实施优化的微米．纳米为0．1402μm金刚石复合涂层沉积工艺，得到表面平整、光滑、平均粗糙度的优质金刚石复合涂层。该涂层与基体附着力高，压痕测试其临界载荷大于1500N，金刚石复合涂层刀具加工ZAlSi12合金试验表明其切削寿命是无涂层刀具的41倍。     

微波等离子体刻恂对WC—Co硬质合金基体金刚石薄膜附着力的影响

金刚石薄膜的附着力是影响CVD金刚石涂层刀具切削性能的关键因素,本文采用EACVD法在硬质合金（YG6）基体上沉积金刚石涂层;用Ar-H2微波等离子WC－C0衬底进行刻蚀处理,以改变基体表面与金刚石涂层间的界面结构,提高金刚石涂层的附着力;采用压痕法评估涂层附着力,借助SEM等观察刻蚀预处理方法对膜基界面的影响,并对此进行分析和讨论。     

YG6金刚石涂层刀片衬底真空渗硼预处理新技术研究

本文研究了真空渗硼预处理硬质合金基体的表面组织、形貌、粗糙度，并在处理过的YG6刀片基体上，用强电流直流伸展电弧等离子体CVD法沉积金刚石薄膜涂层。结果表明，真空渗硼预处理不仅可以有效的消除或控制钴在金刚石沉积时的不利影响，而且，还显著粗化硬质合金基体表面。因此，提高了金刚石薄膜的质量和涂层的附着力。     

CVD金刚石硬质合金基体的表面预处理方法

开发硬质合金基体上沉积高结合强度、低粗糙度的金刚石涂层是人们非常关注的问题。制约CVD金刚石涂层工具产业化的主要因素是其与硬质合金基体间的附着力。大量实验显示,通过对硬质合金基体表面的预处理,可以提高金刚石涂层与硬质合金基体之间的附着力。本文从物理预处理法、化学预处理法和中间层法等,对硬质合金基体表面预处理后的效果做了较为系统的阐述。指出,不同的预处理方法对硬质合金基体与金刚石涂层之间的附着力影响是不一样的。     

化学气相沉积金刚石膜工业应用

成果成熟程度 已经解决在硬质合金衬底上生长均匀致密、附着 良好的金刚石膜的技术 成果的特点 金刚石薄膜涂层硬质合金工具由于性能优异、成 本相对较低(与PCD和金刚石厚膜钎焊工具相比)、可 以适应于复杂形状工具衬底沉积、以及可能大批量沉 积等优点,具有非常好的市场前景. 金刚石薄膜涂层硬质合金工具开发的关键是解决 金刚石薄膜在硬质合金衬底上的生长(沉积)和良好附 着的技术.本项目成果采用独特的衬底预处理和优化 的金刚石膜沉积工艺已经解决了Co对金刚石膜生长 和附着的有害影响问题.在YG类硬质合金工具衬底 所沉积的金刚石膜涂层厚度最大可达20～30μm.用洛 氏硬度压痕法评定的金刚石膜附着力时的无裂纹临界 载荷达1500N以上.在铣削A1-12wt%Si合金时,金 刚石薄膜涂层的YG6铣刀比未涂层硬质合金刀片使 用寿命可提高13倍以上.     

微型硬质合金钻头上金刚石涂层研究

WC-Co硬质合金钻头经过短时间酸腐蚀和微波等离子体硼氮化处理后,利用热丝CVD方法生长金刚石薄膜,并在电路板和玻璃板上进行了附着力测试.研究表明:钻头垂直于热丝放置,钻头端部为最高硬度的(111)面,有利于改善钻头切削加工性能;短时间酸腐蚀只去掉了钻头表面的钴,不降低表面硬度.同时酸腐蚀手段提高了表面粗糙度,避免了在随后的硼氮化处理时在WC表层形成低附着力的硼化物层,提高了金刚石薄膜附着力.在电路板及玻璃板上钻孔的测试结果表明,金刚石薄膜涂层钻头具有更高的寿命.     

CN1632165一种在硬质合金工具上制备金刚石涂层的方法

本发明提供了一种在硬质合金工具上制备金刚石涂层的方法。采取等离子体CVD技术，由含有氢、碳和硅元素的气体混合物为反应气体，在硬质合金工具上沉积含有金刚石相和硅的金刚石涂层；其中，硅是在金刚石涂层的CVD过程进行的同时，被沉积到金刚石涂层中以及金刚石涂层与硬质合金工具的界面处的；硅元素在金刚石涂层与硬质合金工具界面处的存在与富集使金刚石涂层对硬质合金工具形成高的附着力。所述的CVD技术包括：微波等离子体CVD技术、热丝CVD技术、直流电弧等离子体CVD技术。本发明的优点在于：有效地提高金刚石涂层的附着力并简化了涂层的制备工艺。     

硬质合金工具强电流直流伸展弧等离子体CVD金刚石涂层的均匀性研究

采用自行研制的强电流直流伸展电弧等离子体CVD设备对真空渗硼预处理的YG6刀片进行了金刚石涂层沉积，并对放于有效沉积区域不同位置沉积出的金刚石涂层刀片以及刀片自身不同位置之表面涂层的形貌、厚度、质量进行了分析、研究。结果表明：(1)、硬质合金工具强电流直流伸展弧等离子体CVD金刚石涂层的组织、形貌、厚度、质量都是均匀一致的。(2)、利用强电流直流伸展电弧等离子体CVD设备可进行硬质合金金刚石涂层的批量沉积。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

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.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

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.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

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.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

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).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

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.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

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.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

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.