Results 11 to 20 of about 319 (106)
气孔和晶粒尺寸不均匀系数对方波脉冲大电流作用下高电位梯度氧化锌陶瓷失效的影响
Dianci bileiqi, 2021 氧化锌电阻片在脉冲大电流作用下可能失效,威胁着电力设备及电力系统安全稳定运行。脉冲大电流作用下,电阻片瓷体的失效形式主要源自于瓷体本身的穿孔和炸裂。显微形貌观测结果表明,穿孔通道处有显著的晶粒熔融痕迹和微裂纹,这说明穿孔通道起源于电阻片电流、焦耳热局部集中,导致瓷体熔融和炸裂。基于未破坏区域和穿孔通道区域的微观分析,首次定义了晶粒尺寸分布的不均匀系数,统计分析了气孔及晶粒尺寸分布。计算结果表明,氧化锌电阻片穿孔通道附近气孔含量较多,且晶粒分布更加不均匀 ...
王瑶 +9 more
doaj
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT Zirconium dioxide (ZrO2) thin films are critical materials owing to their thermal stability, mechanical durability, and optical transparency enabling applications in photonic, sensing, and electronic devices. However, achieving uniform deposition via plasma‐enhanced chemical vapor deposition (PE‐CVD) has remained challenging due to poor ...
Nour Manafikhi +4 more
wiley +1 more source
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT Additively manufactured AlCoFeNi series eutectic high‐entropy alloys (EHEAs) exhibit nonequilibrium dual‐phase microstructure in the as‐printed state, allowing them to be easily tailored through annealing to explore their strength–toughness potential.
Huidong Wu +13 more
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Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT The evolution of the γ′−Ni3(Al, Ti) phase in superalloys is governed by a coupled coalescence‐ripening mechanism driven by elemental diffusion. In this study, thermal exposure experiments were performed at 750°C and 800°C for durations ranging from 100 to 20,000 h.
Zhaotian Wang +5 more
wiley +1 more source
Size effect on crystallite microstructure in nanocrystalline brookite-based TiO2(纳米板钛矿基TiO2的晶粒尺寸效应)
Zhejiang Daxue xuebao. Lixue ban, 2001 借助精确的X射线衍射测量，结合独立衍射峰对不同晶粒度纳米板钛矿基TiO2样品中板钛矿和金红石相的微结构参量进行了较细致的研究，给出了标征物相、晶面指数(hk1)和晶面间距dhkl值，详细分析结果的系列XRD谱，并得到晶面间距、晶格常数、轴比、晶胞体积等参数数值及其相对常规粗晶的变化情况，从而初步揭示出其晶粒微结构的尺寸效应.作者首次发现，纳米板钛矿基TiO2样品中板钛矿和金红石相晶粒均存在着非单调的各向异性晶格畸变.
LIUXiang-dong(刘向东) +4 more
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Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT Porous NiTi alloys are widely used in biomedical and engineering fields. Using the PBF‐LB technique, the TPMS and Voronoi porous parts with a porosity of ∼67% and a minimum feature size of 0.15 ± 0.02 mm were fabricated. Although the bulk sample fabricated with the same parameters is defect‐free, μ‐CT reconstruction on the porous sample ...
Wen‐Hao Zeng +7 more
wiley +1 more source
Dianci bileiqi, 2022 作为重要的过电压防护元件,ZnO压敏电阻片的性能也需要不断提高。对ZnO压敏电阻片制备工艺中聚乙烯醇(PVA)的影响进行了研究。通过对比不同PVA种类及含量对造粒的影响后发现,选用的PVA聚合度越高,烧结陶瓷的晶粒尺寸就越小;PVA的添加量越多,晶粒尺寸也越小;其次PVA的聚合度会影响到压敏陶瓷的晶界电阻和击穿场强,它们之间成正相关的趋势,但是过量添加PVA会导致其晶界电阻活化能减小,压敏特性降低,导致泄漏电流密度增大;采用低聚合度的PVA会改善电气性能,即提升其压敏特性并降低泄漏电流密度;造粒过程中 ...
张兆华 +9 more
doaj
Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT Nanocomposite permanent magnets with reduced rare‐earth content represent a promising class of materials for next‐generation high‐performance applications. However, asynchronous precipitation of soft and hard magnetic phases often results in grain size mismatch and limited coercivity.
Xiaowei Zhang +6 more
wiley +1 more source
稀土氧化物对ZnO-Bi2O3系压敏陶瓷晶粒分布及电气性能的影响
Dianci bileiqi, 2008 研究了稀土氧化物Ce2O3、Gd2O3、La2O3、Y2O3对ZnO-Bi2O3系压敏陶瓷晶粒尺寸和电气性能的影响,结果表明,稀土氧化物可有效地抑制ZnO晶粒的生长,掺杂Ce2O3、Gd2O3、La2O3、Y2O3后,晶粒的主要分布分别为0～18μm、0～14μm、0～11μm、0～16μm;平均晶粒尺寸下降,其中掺杂Gd2O3后晶粒尺寸最小,为6.2μm。ZnO晶粒分布的标准方差明显下降,改善了晶粒尺寸分布的均匀性。掺杂稀土氧化物后,电位梯度显著提高,E1mA达到了427.5V/mm ...
李盛涛, 成鹏飞, 王玉平, 朱斌
doaj
Rare Metals, Volume 45, Issue 1, January 2026.ABSTRACT TA18 alloy is an ideal material for piping systems in the aerospace field, the low notch sensitivity and high damage tolerance enhance its engineering application value. However, the complex failure mechanism influenced by strain gradient necessitates further improvement of the service stability for TA18 alloy in practical engineering ...
Xin Du +6 more
wiley +1 more source