含铁低镍白色金合金镍渗出及抗变色性能

研究Fe元素部分取代镍对白色金合金镍渗出以及抗变色性能影响.指出当Fe等元素取代合金中的部分Ni元素后,由于镍含量降低,合金的镍释放率出现下降,镍降低导致表面镍钝化膜的破坏.当镍质量分数低于2.5%时,合金的镍释放量反而升高.Fe对合金的漂白效果弱于镍,Fe的加入会导致合金抗变色性能降低.均匀化退火热处理对该实验系列金合金材料的抗变色性能影响不大,但可减少合金成分的偏析,有效降低合金的镍渗出量.     

一种白光测速仪在热锯区域中的应用

阐述白光测速仪的工作原理及优缺点,介绍其在莱钢大H型钢生产线热锯区域的应用.     

不同初始损伤白砂岩高温处理后的力学性能研究

通过进行不同初始损伤程度白砂岩在不同等级高温处理后的力学试验,分析了温度和初始损伤对白砂岩的杨氏模量、峰值应力和显微结构等方面的影响。试验结果表明:随着温度的升高,受到初始损伤的白砂岩试件的杨氏模量和抗压强度都呈下降的趋势,初始损伤越大,高温对白砂岩造成的影响越大。通过显微镜观察到随着温度的升高,试块的晶体变小,颗粒的破坏更为破碎,岩屑更多。此外,通过对试验数据的整理,建立了不同初始损伤等级和不同温度等级下白砂岩的本构关系曲线。     

Full color white light,temperature self-monitor,and thermochromatic effect of Cu+ and Tm3+ codoped germanate glasses

Lighting sources with full-color visible output are widely preferred in practical applications. In addition, modern lighting sources also tend to be intelligentized, and the intelligentization asks for smart luminescence materials. In this work, we attempt to develop novel full-color emitting material with temperature sensing and thermochromatic ability. To this end, the Cu²⁺ is successfully reduced to Cu⁺ which is incorporated into the germanate glasses. The glasses are prepared via a melt-quenching technique using graphite powders as reducing reagent. The supper-broadening of the excitation and the emission spectra of Cu⁺ in the germanate glasses are observed. Full-color emission is realized by introducing Tm³⁺ as co-dopant to provide the blue component in the spectra. The energy transfer behavior between Cu⁺ and Tm³⁺ is investigated, and it is found that these two luminescence centers are independently existent without energy transfer between them. The chromatic properties of the Cu⁺/Tm³⁺ co-doped glasses are tuned by Tm³⁺ concentration and excitation wavelength. The temperature sensing based on the fluorescence intensity ratio technique is demonstrated, and a constant sensitivity for the temperature detection is obtained. Moreover the thermochromatic property is also investigated, and it is found that the studied Cu⁺/Tm³⁺-doped glasses exhibit excellent thermochromatic performance.     

Broadband excited Na3Tb(PO4)2:Ce3+/Eu2+ green/yellow-emitting phosphors with high color purity for LED-based application

To enhance the display quality of light-emitting diodes (LEDs), it is of great significance to exploit green/yellow-emitting phosphors with narrow emission band, high quantum yield, and excellent color purity to satisfy the application. Herein, orthophosphate-based green/yellow-emitting Na₃Tb(PO₄)₂:Ce³⁺/Eu²⁺ (NTPO:Ce³⁺/Eu²⁺) phosphors have been successfully synthesized by a facile solid-state reaction method. The absorption band of NTPO samples was extended to the near-ultraviolet region and the absorption efficiency was significantly improved owing to a highly efficient energy transfer from Ce³⁺/Eu²⁺ ion to Tb³⁺ ion in NTPO host certified by time-resolved PL spectra. Upon 300 nm excitation, the NTPO:Ce³⁺ is characterized by ultra-narrow-band green emission of Tb³⁺ with an absolute quantum yield of 94.5%. Unexpectedly, NTPO:Eu²⁺ emits bright yellow light with a color purity of 73% as a result of the blending of green light emission from Tb³⁺ and red light emission from Eu³⁺. The thermal stability has been improved by controlling the stoichiometric ratio of Na⁺. The prototype white LED used yellow-emitting NTPO:Eu²⁺ phosphor has higher color-rendering index (Ra = 83.5), lower correlated color temperature (CCT = 5206 K), and closer CIE color coordinates (0.338, 0.3187) to the standard white point at (0.333, 0.333) than that used green-emitting NTPO:Ce³⁺ phosphor, indicating the addition of the yellow light component improved the Ra of the trichromatic (RGB) materials.     

60Mn环件断裂分析

60Mn环件在装配150h后发生崩裂.利用断口分析、化学成分分析、显微组织检验以及有限元计算对断裂件进行了分析.结果表明,环件中存在白点,白点在装配应力和内部氢压的作用下发生滞后扩展,当白点裂纹扩展到临界尺寸时,裂纹尖端的应力强度因子超过零件材料的断裂韧度,从而发生崩裂.     

高耐蚀性热镀锌板的钝化处理工艺探讨

介绍了热镀锌板钝化膜的形成机理 ;针对攀钢热镀锌板出现白锈、黑斑等问题 ,分析了钝化液pH值、添加剂及操作条件对钝化膜质量的影响 ,同时提出了改进热镀锌板耐蚀性能的措施     

高铬白口铸铁复合孕育的作用及动力学条件

采用V渣+Ti+Zn对高铬白口铸铁进行复合孕育。在炉内、炉外实行“二步法”处理并按孕育合金异质形核的生核能大小设计分级处理的顺序,起到了控制碳化物的析出量和改善析出形态、净化铁液、净化晶界、细化晶粒等良好的孕育效果。     

Effects of secondary carbide precipitation and transformation on abrasion resistance of the 16Cr-1Mo-1Cu white iron

The relationship between secondary carbide precipitation and transformation of the 16Cr-1Mo-1Cu white iron and abrasion resistance were investigated. The results show that secondary carbide precipitation and transformation at holding stage play an important role in the hardness and abrasion resistance. After being held for a certain time at 853 K for subcritical treatment, the grainy secondary carbide, (Fe,Cr)₂₃C₆, precipitated first and then Fe₂MoC or MoC carbides precipitated in the alloy, both of which improve the bulk hardness and abrasion resistance of the alloy. The reasons for these improvements are the secondary carbide precipitates from the austenite and the retained austenite transforms into the martensite, both make the matrix strengthen. So the matrix has more effective support to the harder eutectic carbide against exterior abrasion. With expanding the holding time, the in situ transformation from the granular (Fe,Cr)₂₃C₆ carbide into laminar M₃C carbide causes the formation of the pearlitic matrix and an associated decrease of the alloy abrasion resistance.     

热连轧机轧辊用多元白口铁的冶金技术

从合金设计、凝固组织、凝固顺序、相图、相转变行为和热处理特性等方面综述多元白口铁作为热连轧精轧机架工作辊的新材质的研发.结果表明,共晶碳化物的类型和形态能通过合金成分组合控制.从连续冷却转变图获得的相转变行为对热处理过程提供了有用的指导.投入实际应用时其抗磨性优于常规轧辊.