退火对Inconel718合金氢脆特性的影响

通过实施不同的退火热处理工艺，调整合金中强化相的析出状态，制备具有不同退火状态的几组拉伸试样。对每组试样在未充氢和充氢后按相同的条件进行拉伸试验对该组试样的脆化作用。通过比较不同组试样的脆化表现通过比较未充氢试样和充氢后试样的强度和塑性，评价氢考察退火状态对Inconel 718氢脆倾向的影响。试验结果表明，随着退火程度的加强，强化相体积分数减少，氢引起的塑性损失下降，即抗氢脆性能改善。该结果说明，强化相γ″和γ′对Inconel 718合金的氢脆有促进作用。因此，根据不同工业应用要求，在符合强度要求的前提下，可以通过热处理改善零件的抗氢脆性能。     

Penetration treatment of plasma-sprayed ZrO2 coating by liquid Mn alloys

The penetration phenomena of liquid manganese (Mn) alloy into porous ZrO₂ (8 vvt % Y₂O₃) coating plasma sprayed on SS400 steel substrate was studied by heating in a vacuum atmosphere. The improvement in mechanical properties of the coating by heat treatment with liquid Mn alloys was examined. Liquid Mn alloys, such as Mn-Cu, Mn-Sn, and Mn-In, rapidly penetrated the coating and formed a chemical bond between the coating and the substrate. The densification of the ZrO₂ coating occurred when ZrO₂ particles were sintered with liquid Mn alloys that penetrated the porous coating. The dense coating was free of porosity, and its hardness increased after heat treatment with Mn alloys, compared with assprayed ZrO₂ coating. Moreover, the fracture toughness of the coating reached the same levels as those of sintered yttria-stabilized PSZ.     

激光退火对Inconel 718微观组织和硬度的影响

研究激光退火对Inconel718时效合金的显微组织和硬度的影响.一台2.5kW的CO2激光机被用来照射试样的表面.在激光能作用下,试样表面层被加热后空冷.通过控制激光工艺参数,在表面不发生熔化的前提下,能够使一定厚度表面层内的硬度降低到标准退火合金的水平,而不影响试样内部母材的硬度.显微组织观察显示表面层的基体强化相(γ″和γ‘)在激光照射过程中被固溶,而其它二次相没有变化.γ″和γ‘的固溶被确定是表面层硬度下降的原因.在其它试验条件不变时,确立了退火层生成时由激光散焦距离和扫描速度描述的工艺参数范围.     

Repeatedly foldable AMOLED display

In this study, a 5.9‐inch foldable active‐matrix organic light emitting diode (AMOLED) display was developed. A folding test was performed repeatedly. The display survived the folding test (100,000 folds) with a curvature radius of 2 mm. To protect an organic light emitting diode (OLED) against moisture, inorganic passivation layers are provided on the upper and lower sides of the flexible display. Using our transfer technology, high density passivation layers can be obtained. The measured water vapor transmission rate of the layer is 7 × 10^?6 g/m²?day or less, which improves OLED reliability. With these techniques, we have developed a book‐type display, which is repeatedly foldable like a book, and a tri‐fold display including a display area, which is foldable in three.     

Scattering mechanism and reduction of insertion losses in a laminated polarization splitter

We experimentally found the unexpected phenomena of scattering in laminated polarization splitters (LPS's) composed of a-Si:H-SiO(2) multilayer and studied its mechanism. The scattering phenomena strongly depend on the incident angle and polarization of the incident light. To reduce the scattering loss in LPS's, a multilayer with flat layer boundaries is fabricated with rf bias sputtering. As a result, the insertion loss of the LPS is reduced to ~ 1 × 10(-3) dB/ μm, which is acceptable for practical uses.     

Theoretical analysis of the spatial phase-matching loci for second-harmonic generation and multiwave-mixing interactions

We report a theoretical analysis on spatial noncolinear phase matching of multiwave mixing and its application to a second-harmonic-generation (SHG) experiment. From the numeric calculations, the noncolinear phase-matching properties in general situations were determined. The theory gives the applicability for all noncolinear phase matching. Fine coincidences between theoretical calculations and observed spatial loci on noncollinear phase-matching SHG were confirmed. Relations that allow the calculation of the noncollinear phase-matching angle for any case of SHG are established. As an example, the noncolinear phase-matched SHG pattern on a screen is calculated numerically in the case of SHG of 1064 nm from a Nd:YAG laser under the phase-matched condition for two organic nonlinear crystals: 1-(2-thienyl)-3-(4-methyphenyl) propene-1 (TC-28), which is biaxial, and (2-furyl) methacrylic anhydride (FMA), which is uniaxial. Experimental results compared quite favorably with the theoretical analysis. Noncolinear phase matching may be of great practical interest in optical multiwave-mixing processes, such as optical parametric oscillation and optical parametric amplification. This technique also can be used for the measurement of crystal optical constants.     

Optimization of facial skin temperature-based anomaly detection model considering diurnal variation

Artificial Life and Robotics - The amount of blood under the surface of skin is controlled by the autonomic nervous system and directly influences the facial skin temperature. Classification models...     

Threshold for Millimeter-Wave (60 GHz)-Induced Ocular Injury

Journal of Infrared, Millimeter, and Terahertz Waves - Millimeter waves (MMW) absorbed by skin or cornea may induce damage by heat. We have developed a 60 GHz MMW exposure-induced eye...     

Delignification kinetics of empty fruit bunch (EFB): a sustainable and green pretreatment approach using malic acid-based solvents

Recently, the development of efficient and environmentally benign solvents has received great attention to replace current harsh organic solvents. In this context, low-transition-temperature mixtures (LTTMs) have emerged as favorable green solvents for biomass delignification. Palm oil biomass, empty fruit bunch (EFB) was pretreated with commercial l-malic acid and microwave hydrothermally extracted cactus malic acid-derived LTTMs at 60, 80, and 100 °C. The LTTMs applied in this study were derived from malic acid–choline chloride–water and malic acid–monosodium glutamate–water with a molar ratio of 2:4:2 and 3:1:5, respectively. Three first-order reactions were used to express the delignification kinetic model of EFB. The first term was based on the initial stage and assigned as infinite due to the fast rate of delignification which could not be detected. The second and third terms were proportional to bulk and residual delignification stages. A good agreement was obtained between the kinetic model and the experimental data obtained in this study with R²?≥?0.91. The activation energies for the delignification reactions using l-malic acid and cactus malic acid-based LTTMs in the bulk and residual stages were approximated as 36–56 and 19–26 kJ/mol and 34–90 and 47–87 kJ/mol, respectively.