SELECTED ABSTRACTS OF ARTICLES ON RARE METALS FROM CHINESE PERIODICALS

ＣＯＮＴＥＮＴＳ1.ＥｘｔｒａｃｔｉｖｅＭｅｔａｌｌｕｒｇｙ (1)2 .ＭｅｔａｌＭａｔｅｒｉａｌｓａｎｄＴｅｃｈｎｏｌｏｇｙ (1)3.Ｓｅｍｉｃｏｎｄｕｃｔｏｒ (1)0 0 - 1- 1　　ＰｈｙｓｉｃａｌＰｒｏｐｅｒｔｉｅｓａｎｄＴｈｅｒｍａｌＳｔａｂｉｌｉｔｙｏｆＨｉｇｈＰｕｒｉｔｙＴｕｎｇｓｔｅｎＳｕｌｆｉｄｅＭｉｃｒｏＰｏｗｅｒ　　Ｔｈｅｐｈｙｓｉｃａｌｐｒｏｐ ｅｒｔｉｅｓｏｆｈｉｇｈｐｕｒｉｔｙｔｕｎｇｓｔｅｎｄｉｓｕｌｆｉｄｅｍｉｃｒｏｐｏｗｄｅｒ ,ｉｎｃｌｕｄｉｎｇｉｔｓｄｅｎｓｉｔｙ ,ｃｏｍｐｏｓｉ…     

Rare earth activated sintering of MoSi_2 and its electric conductivity

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｅｒｍｅｔａｌｌｉｃＭｏＳｉ2 ｈｏｌｄｓｃｏｎｓｉｄｅｒａｂｌｅ ｐｒｏｍｉｓｅｆｏｒａｗｉｄｅｖａｒｉｅｔｙｏｆｅｌｅｖａｔｅｄｔｅｍｐｅｒａｔｕｒｅｓｔｒｕｃｔｕｒａｌａｐｐｌｉｃａｔｉｏｎｓａｔｔｅｍｐｅｒａｔｕｒｅｓａｂｏｖｅ10 0 0℃[1] .ＳｉｎｃｅＭａｘｗｅｌｌｆｉｒｓｔｐｕｔｆｏｒｗａｒｄｔｈｅｈｙｐｏｔｈｅｓｉｓｔｈａｔＭｏＳｉ2ｃｏｕｌｄｂｅａｐｏｔｅｎｔｉａｌｓｔｒｕｃｔｕｒａｌｍａｔｅｒｉａｌｉｎｔｈｅｅａｒｌｙ1950ｓ,ｍａｔｅｒｉａｌｓｃｉｅｎ…     

Ternary alloying of Mo_5Si_3 with Zr, Ti, Co and V

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｌｉｃｉｄｅｓａｒｅｕｓｅｄａｓｖａｒｉｏｕｓｐｒｏｔｅｃｔｉｖｅｃｏａｔｉｎｇｓａ ｇａｉｎｓｔｗｅａｒ ,ｃｏｒｒｏｓｉｏｎａｎｄｏｘｉｄａｔｉｏｎ ,ａｎｄａｓｉｎｔｅｇｒａｔ ｅｄｃｉｒｃｕｉｔｆｉｌｍｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｈｉｇｈｈａｒｄｎｅｓｓ ,ｈｉｇｈｅｌｅｃｔｒｉｃａｌａｎｄｔｈｅｒｍａｌｃｏｎｄｕｃｔｉｖｉｔｙａｎｄｇｏｏｄｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅａｔｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓ .Ｉｎｐａｒｔｉｃｕｌａｒ ,ＭｏＳｉ2ｉｓｐｕｔｉ…     

Molecular dynamics of structural properties of molten CaO-SiO2 with varying composition

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｔｕｄｙｏｆｍｏｌｔｅｎｓｔｒｕｃｔｕｒｅｏｆＣａＯ ＳｉＯ2 ,ｗｈｉｃｈａｃｔａｓｔｈｅｂａｓｉｃｆａｃｔｏｒｉｎｆｌｕｅｎｃｉｎｇｔｈｅｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｓｉｌｉｃａｔ     

Self-propagating high-temperature synthesis in Ti-W-C system

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｅｌｆ ｐｒｏｐａｇａｔｉｎｇｈｉｇｈ ｔｅｍｐｅｒａｔｕｒｅｓｙｎｔｈｅｓｉｓ(ＳＨＳ)ｏｒｃｏｍｂｕｓｔｉｏｎｓｙｎｔｈｅｓｉｓ ,ｗａｓｄｅｖｅｌｏｐｅｄｂｙＭｅｚｈａｎｏｖｅｔａｌｉｎｔｈｅ 196 0’ｓ .Ｃｏｍｐａｒｅｄｔｏｔｒａｄｉｔｉｏｎ ａｌｍｅｔｈｏｄｓ,ｉｔｓａｄｖａｎｔａｇｅｓｉｎｃｌｕｄｅｈｉｇｈ ｐｕｒｉｔｙｏｆｐｒｏｄｕｃｔｓ ,ｌｏｗｅｎｅｒｇｙｒｅｑｕｉｒｅｍｅｎｔ ,ｒａｐｉｄｒｅａｃｔｉｏｎａｎｄｓｉｍｐｌｉｃｉｔｙｏｆｐｒｏｃｅｓｓ[1] .Ｂｅｃａ…     

Effect of low temperature treatment on tensile yield strength of SiCw/6061 Al alloy composites

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎＳｉＣｗ/ 60 61ｃｏｍｐｏｓｉｔｅｓ,ｔｈｅｄｉｆｆｅｒｅｎｃｅｏｆｔｈｅｔｈｅｒｍａｌｅｘｐａｎｓｉｏｎｃｏｅｆｆｉｃｉｅｎｔｂｅｔｗｅｅｎｒｅｉｎｆｏｒｃｅｍｅｎｔ(ＳｉＣｗ)ａｎｄｍａｔｒｉｘ(Ａｌａｌｌｏｙ)ｉｓｖｅｒｙｌａｒｇｅ.Ａｓａｃｏｎ ｓｅｑｕｅｎｃｅ,ｗｈｅｎｔｈｅｃｏｍｐｏｓｉｔｅｓｉｓｃｏｏｌｉｎｇｄｏｗｎｆｒｏｍｔｈｅｍａｎｕｆａｃｔｕｒｉｎｇｔｅｍｐｅｒａｔｕｒｅｔｏｒｏｏｍｔｅｍｐｅｒａｔｕｒｅ ,ａｌａｒｇｅｍｉｓｍａｔｃｈｔｅｎｓｉｌｅｓｔｒ…     

Removal of sulfur in coke oven gas by mixing ZnO-based additive into coal

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｕｌｆｕｒｄｉｓｔｒｉｂｕｔｉｏｎｉｎｃｏｋｉｎｇｐｒｏｃｅｓｓｉｎｃｌｕｄｅｓｔｗｏｐａｒｔｓ .ＯｎｅｐａｒｔｉｓｇｏｉｎｇｉｎｔｏＣＯＧａｓＨ2 Ｓ ,ＣＳ ,ＣＯＳａｎｄＣ2 Ｈ2 ＳＨ .ＴｈｅｏｔｈｅｒｐａｒｔｉｓｒｅｓｉｄｕａｌｉｎｃｏｋｅａｓＦｅＳ ,ＣａＳ ,Ｓ2 ａｎｄｓｏｏｎ .Ｔｒａｄｉｔｉｏｎａｌｌｙ ,ｔｈｅｒｅｍｏｖａｌｏｆｓｕｌｆｕｒｏｆＣＯＧｉｓｂｙｓｐｒａｙｉｎｇａｍｍｏｎｉａｗａｔｅｒｉｎｔｏｈｏｔｃｏａｌｇａｓｔｏｆｏｒｍａｍｍｏｎｉｕｍｓｕｌｆａｔ…     

Preparation of heat-resistant aluminum alloy pipe blanks by multi-layer spray deposition

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＦＶＳｓｅｒｉｅｓｏｆｈｅａｔ ｒｅｓｉｓｔａｎｔａｌｕｍｉｎｕｍａｌｌｏｙｓｗｅｒｅｄｅｖｅｌｏｐｅｄｕｓｉｎｇｔｈｅ ｐｌａｎａｒｆｌｏｗｃａｓｔｉｎｇｂｙＡｍｅｒｉｃａｎＡｌｌｉｅｄＳｉｇｎａｌｓＣｏｍｐａｎｙｉｎ 1986 [1] .Ｂｅ ｃａｕｓｅｏｆｔｈｅｉｒｅｘｃｅｌｌｅｎｔｓｔｒｅｎｇｔｈｓａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅａｎｄｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓ ,ｈｉｇｈｅｌａｓｔｉｃｍｏｄｕｌｉａｎｄｇｏｏｄｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅ ,ｔｈｅｙｈ…     

Resistance of Si2N2O ceramics to oxidation and erosion of molten silica

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｌｉｃｏｎｏｘｙｎｉｔｒｉｄｅ(Ｓｉ2Ｎ2Ｏ)ｃｅｒａｍｉｃｓｓｈｏｕｌｄｂｅｒｅｇａｒｄｅｄａｓａｆｉｎｅｒｅｆｒａｃｔｏｒｙｂｅｃａｕｓｅｏｆｉｔｓｅｘｃｅｌｌｅｎｔｒｅｓｉｓｔａｎｃｅｔｏｏｘｉｄａｔｉｏｎａｎｄｅｒｏｓｉｏｎｏｆｍｏｌｔｅｎｓｉｌｉｃａａｎｄｎｏｎｆｅｒｒｏｕｓｍｅｔａｌｓ.Ｉｎａｄｄｉｔｉｏｎ,ｉｔｈａｓｂｅｅｎｒｅｃｏｇｎｉｚｅｄａｓａｐｒｏｍｉｓｉｎｇｅｎｇｉｎｅｅｒｉｎｇｍａｔｅｒｉａｌｂｅｃａｕｓｅｏｆｉｔｓｇｏｏｄｍｅｃｈａｎｉｃａｌ…     

Preparation and mechanical properties of Si2N2O ceramics

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｌｉｃｏｎｏｘｙｎｉｔｒｉｄｅ (Ｓｉ2 Ｎ2 Ｏ)ｃｅｒａｍｉｃｓｓｈｏｕｌｄｂｅｒｅｇａｒｄｅｄａｓａｆｉｎｅｒｅｆｒａｃｔｏｒｙｂｅｃａｕｓｅｏｆｉｔｓｅｘｃｅｌｌｅｎｔｒｅｓｉｓｔａｎｃｅｔｏｏｘｉｄａｔｉｏｎａｎｄｅｒｏｓｉｏｎｏｆｍｅｌｔｓｉｌｉｃａａｎｄｎｏｎｆｅｒｒｏｕｓｍｅｔａｌｓ.Ｉｎａｄｄｉｔｉｏｎ ,ｉｔｈａｓｂｅｅｎｒｅｃｏｇｎｉｚｅｄａｓａ ｐｒｏｍｉｓｉｎｇｅｎｇｉｎｅｅｒｉｎｇｍａｔｅｒｉａｌｂｅｃａｕｓｅｏｆｉｔｓｇｏｏｄｍｅｃｈａｎｉｃａｌ…     

Effects of minor Sc and Zr additions on mechanical properties and microstructure evolution of Al−Zn−Mg−Cu alloys

The effects of minor Sc and Zr additions on the mechanical properties and microstructure evolution of Al−Zn−Mg−Cu alloys were studied using tensile tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ultimate tensile strength of the peak-aged Al−Zn−Mg−Cu alloy is improved by about 105 MPa with the addition of 0.10% Zr. An increase of about 133 MPa is observed with the joint addition of 0.07% Sc and 0.07% Zr. For the alloys modified with the minor addition of Sc and Zr (0.14%), the main strengthening mechanisms of minor addition of Sc and Zr are fine-grain strengthening, sub-structure strengthening and the Orowan strengthening mechanism produced by the Al₃(Sc,Zr) and Al₃Zr dispersoids. The volume of Al₃Zr particles is less than that of Al₃(Sc,Zr) particles, but the distribution of Al₃(Sc,Zr) particles is more dispersed throughout the matrix leading to pinning the dislocations motion and restraining the recrystallization more effectively.     

Microstructures and mechanical properties of Al-Mg and Al-Zn-Mg based alloys containing minor scandium and zirconium

1　INTRODUCTIONAddingofminorMn ,Cr ,Ti,B ,Zr ,Sc ,Agintoaluminumalloyscanremarkablychangethemi crostructuresandpropertiesofaluminumalloys[18] .Amongthem ,theeffectofminorScandZrhasre ceivedspecialattention .Onthe 1stInternationalScandiumConferenceheldinMoscowin 1994 ,Rus sianmetallurgistsdescribedtheapplicationprospectofaluminumalloyscontainingScinaerospace ,aviation ,warshipsandnuclearindustry ,whichhasstimulatedmanyindustrialcountries’researchinterestinthiskindofalloys .Atpresent…     

Effect of minor Sc and Zr on microstructure and mechanical properties of Al-Zn-Mg-Cu alloy

1 Introduction The microstructure and properties of aluminium alloys are strongly affected by adding small quantities of scandium. Minor Sc may improve the temperature of recrystallization and fracture toughness, decrease the sensitivity of stress corrosi…     

Effects of minor Sc on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr based alloys

Five kinds of Al-Zn-Mg-Cu-Zr based alloys with different Sc additions were prepared by ingot metallurgy. The effects of minor Sc on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr based alloys were investigated using tensile tests, optical microscopy (OM), and transmission electron microscopy (TEM). The results show that the ultimate tensile strength and yield strength are improved by 94 and 110 Mpa, respectively, and the elongation to failure remains at a reasonable extent (11.1%) in the Al-Zn-Mg-Cu-Zr based alloy with 0.21 wt.% Sc addition after solution heat treatment at 475℃ for 40 min and then aged at 120℃ for 24 h. The addition of minor Sc induces the formation of Al3(Sc,Zr) particles, which are highly effective in refining the cast microstructures, retarding recrystallization, and pinning dislocations. The increment of strength is attributed mainly to fine grain strengthening, precipitation strengthening of Al3(Sc,Zr) particles, and substructure strengthening.     

铝合金细化相Al3(Zr,Sc)的能量和弹性性质的第一性原理研究

微合金化是强化铝合金的重要手段，Sc作为铝合金有效的细化剂而引起广泛关注。实验研究表明，在铝基体中同时添加Zr和Sc，在铝基质中形成Al3(Zr,Sc)细化相，可以实现更好的晶粒细化。本文基于密度泛函理论的第一性原理方法，系统地研究了不同Sc/Zr配比下形成的Al3(Zr,Sc)细化相的能量和弹性性质。结果表明，当Sc/Zr不高于1/3时，Al3(Zr,Sc)相具有较大的形成焓绝对值，细化相将优先于Al3(Zr,Sc)相析出。同时，Sc元素的加入有利于界面的形成，提高界面的结合强度和润湿效果，但高于1/3的Sc/Zr比对界面性能的提高并无积极作用。并且，Zr的加入可以有效提高细化相的弹性性能，并削弱Al3Sc的弹性各向异性特征。此理论研究指出，微合金化Zr和Sc的共同添加时Sc/Zr不高于1/3时，可以保证细化效果并大大降低合金的成本。     

含钪Al-9.0Zn-2.5Mg-1.2Cu-0.15Zr合金铸态组织与力学性能

采用铸锭冶金法制备了Al-9.0Zn-2.5Mg-1.2Cu-0.15Zr、Al-9.0Zn-2.5Mg-1.2Cu-0.12Sc-0.15Zr和Al-9.0Zn-2.5Mg-1.2Cu-0.20Sc-0.15Zr三种合金,采用金相显微镜、扫描电子显微镜和透射电子显微镜,研究了三种合金铸态及不同热处理状态下的显微组织,测试了不同热处理状态下合金的力学性能。结果表明,Sc含量增加可以提高Al-Zn-Mg-Cu-Zr合金的抗拉强度和伸长率,Al-9.0Zn-2.5Mg-1.2Cu-0.15Zr-0.20Sc经固溶和T6处理后,抗拉强度达到774.6 MPa,伸长率为8.3%。其作用机理主要为Sc含量增加,使合金中Al(3 Sc,Zr)引起的细晶强化、亚结构强化和弥散强化更进一步加强。     

Effect of minor Sc and Zr addition on microstructures and mechanical properties of Al-Zn-Mg-Cu alloys

Three kinds of Al-Zn-Mg-Cu based alloys with 0.22%, 0.36%（Sc＋Zr） （mass fraction, %）, and without Sc, Zr addition were prepared by ingot metallurgy. By using optical microscopy, transmission electronic microscopy and scanning electron microscopy, the effects of microalloying elements of Sc, Zr on the microstructure of super-high-strength Al-Zn-Mg-Cu alloys related to mechanical properties were investigated. The tensile properties and microstructures of the studied alloys under different heat treatment conditions were studied. The addition of minor Sc, Zr results in the formation of Ala（Sc,Zr） particles. These particles are highly effective in refining the microstructures, retarding recrystallization, pinning dislocations and subboundaries. The strength of Al-Zn-Mg-Cu alloys was greatly improved by simultaneously adding minor Sc, Zr, meanwhile the ductility of the studied alloys remains at a higher level. The 0.36%（Sc＋Zr） alloys gain the optimal properties after 465 ℃/h solution and 120 ℃/24 h aging. The increment of strength is mainly due to strengthening of fine grain and substructure and precipitation ofAl3（Sc, Zr） particles.     

Effect of trace Sc and Zr on aging behavior and tensile properties of 2618 alloy

１　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅａｌｕｍｉｎｕｍａｎｄａｌｕｍｉｎｕｍａｌｌｏｙｓａｄｄｅｄｔｒａｃｅｓｃａｎｄｉｕｍｈａｖｅｇｒｅａｔｉｍｐｒｏｖｅｍｅｎｔｉｎｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓ,ｔｈｅｒｍａｌｓｔａｂｉｌｉｔｙ,ｗｅｌｄｂｉｌｉｔｙｅｔｃ［１］．ＳｃａｎｄｉｕｍｉｓｃｏｎｓｉｄｅｒｅｄｔｏｂｅａｈｏｐｅｆｕｌｔｒａｃｅｅｌｅｍｅｎｔｔｏｄｅｖｅｌｏｐａｄｖａｎｃｅｄｗｒｏｕｇｈｔａｌｕｍｉｎｕｍａｌｌｏｙｄｕｅｔｏａｄｉｓｐｅｒｓｅｄｐｈａｓｅＡｌ３Ｓｃｐｒｅｃ…     

Effect of minor Zr and Sc on microstructures and mechanical properties of Al–Mg–Si–Cu–Cr–V alloys

The effects of minor contents of Zr and Sc on the microstructures and mechanical properties of Al–Mg–Si–Cu–Cr–V alloy were studied. The results show that the effects of minor Zr and Sc on the as-cast grain refinement in the ingots, the improvement in the strength of the as-extruded alloys and the restriction of high angle grain boundaries in the aged alloys can be sorted as Al₃Sc>Al₃(Zr,Sc)>Al₃Zr. None of them could stop the nucleation of recrystallization, but Al₃(Zr,Sc) phase is a more effective inhibitor of dislocation movement compared to Al₃Sc in the aged alloys. Compared with the mechanical properties of the aged alloy added only 0.15% Sc, the joint addition of Zr and Sc to the alloy leads to a very slight decrease in strength with even no cost of ductility. Taking both the production cost and the little bad influence on mechanical properties into consideration, an optimal content of Zr and Sc in the Al–Mg–Si–Cu–Cr–V alloy to substitute 0.15% Sc is 0.13% Zr+0.03% Sc.     

Effects of Sc, Zr and Ti on the microstructure and properties of Al alloys with high Mg content

The effects of trace Sc, Zr, and Ti on the microstructure and hardness of Al alloys with high Mg content (Al-6Mg, Al-8Mg, and Al-10Mg) were studied by optical microscope, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brinell hardness. The grain size of the as-cast alloys was refined by the addition of Sc and Zr, and it was further refined by the addition of Ti. With the same contents of Sc, Zr, and Ti, an increase in Mg content was beneficial to the refinement due to the solution of Mg into α-Al. The refined micro-structures of the as-cast alloys were favorable for Brineil hardness. Addition of Sc, Zr, and Ti to the Al-10Mg alloy results in the improve-ment of peak hardness and it is about 45% higher than that of the Al-10Mg alloy, which is due to fine precipitations of Al_3(Sc_(1-x)Zr_x), Al_3(Sc_(1-x)Ti_x), and Al_3(Sc_(1-x-y)Zr_xTi_y).