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phase.The primary solidification phase had an icosahedral structure.The dendritic phase was the W-phase,and eutectic structure phase was the Mg 7 Zn 3 phase.Microstructures of icosahedral phase(I-phase),W-phase and Mg 7 Zn 3 phase in Mg 44 Zn 44 Gd 12 alloy were investigated.The results indicated that the I-phase in Mg 44 Zn 44 Gd 12 alloy was a face-centered icosahedral quasicrystal......
, the coarse Mg-Zn-Y particles (W-phase) were broken up and dispersed homogenously into the Mg matrix. With increasing rotation rates, the size of the W-phase particles at the NZ significantly... deformation between the NZ and TMAZ caused by remarkably different orientation of grains and W-phase particles. The strength of FSW joint reaches 90% of that of its PM.关键词:......
transformed the θ-phase into the W-phase in the 7055 alloy. Minor Sc and Zr additions enhanced the hardness and yield strength of the 7055-T6 alloy by strengthening the grain boundaries and Al3(Sc,Zr) precipitates. However, a further increase in the Sc and Zr fractions did not refine the grains but instead resulted in the formation of the large-sized W-phase and primary coarse Al3(Sc,Zr) phase......
. Meanwhile, the W-phase plays an important role in refining the grain size via continuous dynamic recrystallization (CDRX), companied with a higher maximum texture intensity. Thus, the Mg-6Zn-1Er alloy containing I-phase shows a performance of higher elongation of 20.4%. The Mg-2Zn-2Er alloy including W-phase displays a better tensile strength, and the yield strength (YS) is about 247 MPa. Key words: Mg......
. The results show that the average grain size of Mg-Zn-Cu-Zr magnesium alloy is effectively reduced (from 57 μm to 39 μm) by Y addition. The analysis of XRD indicates the existence of I-phase (Mg3Zn6Y) and W... networks of intergranular phases and the increase of W-phase. Key words: Mg-Zn-Cu-Zr alloy; yttrium; microstructure; mechanical property 1 Introduction Magnesium alloys will have great potential......
it into the a-Mg matrix to some extent;therefore,the amount of W-phase increases.Moreover,prolonged solution treatment decreases the volume fraction of the phases.In the first stage of solution treatment for 14 h...,it improves the corrosion resistance due to the transformation of I-phase into W-phase.In fact,it decreases corrosion potential and simultaneously dissolves intermetallic compounds into the a-Mg matrix......
microstructures from diff erent alloys was formed in the stirred zone.Coarse quasicrystals were broken up and dispersed with most of them being transformed into cubic W-phase particles,and thick 18 R long-period stacking ordered plates were fractured and transformed into fine 14 H-LPSO lamellae in the stirred zone(SZ) experiencing complex material flow under high strain rate.Fine W-phase particles and 14......
Mg-2Zn-0.5Y镁合金半固态等温处理过程中的微观组织演变(英文)刘伟,杨豆豆,权高峰,张英波,姚丹丹西南交通大学摘 要:研究了挤压Mg-2Zn-0.5Y(at%)合金在半固态等温处理过程中的微观组织演变规律.结果表明:挤压态的Mg-2Zn-0.5Y合金包含α-Mg,Mg3-Zn6-Y1(I-Phase)和Mg3-Zn3-Y2(W-phase)3种物相,并且α-Mg的平均晶粒尺寸为7μm.在温度为793 K的半固态等温热处理过程中,晶粒不断长大,直到保温时间达到4.0 min时才出现液相.随着等温处理温度和时间的增加,α-Mg固相颗粒不断长大,并且逐步被液相分离;同时,出现在晶界的液相与颗粒内部的液滴都在不断地增多.研究还发现,当固相率较高时,晶粒间的合并机制与固相颗粒再熔化机制同时起主导作用;然......
of the alloys irregularly. The alloy with more Gd has large dendritic structure and more complicated phase composition which are composed of I-phase lamellar eutectic, W-phase divorced eutectic, Mg...Microstructure and phase compositions of as-cast Mg–3.9Zn–0.6RE(Gd,Y) alloy with different Gd/Y ratiosYang Yang,Kui Zhang,Ming-Long Ma,Jia-Wei YuanState Key Laboratory for Fabrication and Processing......
the precipitation of the W-phase particles, the I-phase almost dissolves into the matrix after solid solution treatment at 480 °C for 10 h (T4 state). The solution-treated alloy was aged at 175 °C... in the XRD pattern. It should be noted that the peaks corresponding to the W-phase appear. It is implied that the W-phase is apt to precipitate from the matrix during the solid solution treatment......