摘要：High-entropy alloys(heAs)contain multiple principal alloying elements,but usually with simple crystal *** are structurally complex phases,but are generally dominated by only one ***,nearequiatomic high-entropy quasicrystals have rarely been reported because they are difficult to prepare experimentally and predict ***,the preparation and crystal structures of near-equiatomic high-entropy quasicrystals have drawn much *** report a quinary decagonal quasicrystal(DQC)with near-equiatomic alloying elements in Al20Si20Mn20Fe20Ga20 melt-spun ribbons,which is the first to our ***,the structural features of the DQC are characterized in *** configurational entropy of both the alloy and DQC satisfies the entropy-based criterion for heAs,suggesting a high-entropy *** findings provide a new strategy to develop high-entropy quasicrystals.

摘要：本文研究了一种新型低密度(~6.24 g cm^(-3))双相AlTiVCoNi高熵合金,其组织结构由有序L21高熵金属间化合物、无序体心立方结构和纳米L21相多层次结构构成.该合金在1200℃+24 h热处理下未发生相结构转变,在此条件下具有优异的高温相结构稳定性,其铸态和热处理态的压缩屈服强度相当,达到~1.6 GPa.另外,该合金在室温和600℃条件下表现出了优异的强塑性匹配和优异的比屈服强度,分别达到了约261和210 MPa g^(-1)cm^(3).该合金的超高强度主要源于有序L21相与体心立方相的半共格界面导致的一种强相结构稳定性和多层次结构的复合强化机制.该合金在800和1000℃压缩过程中出现了动态再结晶软化,使得其高温强度有所降低.这种“具有半共格界面L21+体心立方+纳米L21颗粒”的多层次结构设计为开发新型低密度耐高温高熵合金提供了一种新设计思路.

摘要：对国外钻屑回注技术研究与应用情况进行了总结。通过井下水力压裂方式将钻井废弃物回注到地下是目前海上油气开发钻井废弃物处理最优方法,不仅成本低,而且可以实现废弃物零排放。钻屑回注关键技术环节包括回注工艺流程设计及设备优选、回注地层筛选及注入方式确定、回注浆体压裂设计及回注控制、回注浆体性能调整及影响因素分析、回注评价等。钻屑回注技术的发展趋势是优化每个钻屑回注技术环节、确保钻屑浆体更安全回注到处置地层、减小钻屑回注风险等。随着环保要求的不断提高,钻屑回注技术在我国海上将会得到很好的应用与发展。