钇对M38'合金1000℃氧化性能的影响

本文研究了添加0.1%和0.5Wt%钇对 M38′合金氧化行为和机构的影响。试样在大气中1000℃氧化100hr。实验结果表明,加入0.1%钇的合金,其氧化速率比不加钇合金有明显的降低;将合金中钇含量增加到0.5%,其氧化速率略有增加。三种合金的氧化动力学基本遵从抛物线规律。当氧化70hr 后,不加钇合金的氧化速率向较快方向变化。金相观察到不加钇合金形成一个内氧化带,而含钇乙合金基体内不再产生内氧化。     

钇含量对Mg-Y合金组织及力学性能的影响

研究了钇(Y)含量对金属型铸造Mg-Y合金铸态组织、力学性能以及压缩变形织构的影响。结果表明:Y可以细化Mg-Y合金组织,当钇含量由w(Y)=0增加到w(Y)=3%时,合金的平均晶粒尺寸由300μm减小到55μm;随着钇含量增加,共晶相增加,并产生Mg24Y5第二相粒子; Y可以提高Mg-Y合金室温下的硬度和抗压强度,尤其能显著提高Mg-Y合金高温抗压强度;随着钇含量的增加,基面织构强度由纯镁的9. 1降至Mg-3%Y合金的3. 3。并探讨了Y弱化Mg-Y合金基面织构的机制。     

Co-15wt%Y合金的高温硫化-氧化腐蚀

为检验添加钇对纯钴耐高温－低氧混合气腐蚀的影响,研究了Ｃｏ－１５ｗｔ％Ｙ合金在６００￣７００℃ＣＨ２－ＣＯ２混合气中的腐蚀。合金腐蚀后形成多层结构的腐３蚀产物膜,最外层是单一的硫化钴,中间层为由两金属化合物组成的混合物层。最内层是同氧和硫引起的钇的内腐蚀区。在钇含量达到１５ｗｔ％的条件下未发生钇的选择性外硫化／氧化,这与钇在基体金属中有限的固溶度和合金中出现富钇金属间化合物有关。     

纯钇及Fe—Y合金在H2—H2S气氛中的高温腐蚀

研究了纯钇及含１５％和３０％Ｙ的Ｆｅ－Ｙ合金在硫分压为１０＾－３Ｐａ的Ｈ２－Ｈ２Ｓ混合气中于６００－８００℃的腐蚀行为。     

镁—钇—锌—锆系铸造合金热强性能的研究

镁-钍系合金以适于300℃高温下长期使用的抗蠕变合金著称。但钍具有放射性,故该合金并不令人满意。 近年来,曾有钇对镁合金热强性能具有良好作用的报导。笔者在分析有关文献,探索镁-钇-锆、镁-钇-锌-锆和镁-钇-钕-锌-锆等系的热强性能后,确定对镁-钇-锌-锆系合金在300℃下的性能进行详细研究。本文主要目的是讨论钇和锌在一较宽范围内,其含量变化对合金性能及其组织结构之间的相互关系。     

Fe—Nb—C合金的中温内耗

Fe-Nd-C合金内耗测试表明：700℃,1h水淬合金的Snoek峰较低,而且含Nb越多,Snoek峰高（hs)越低。与通常铁基材料不同,变形导致Fe-Nb-C合金的hs增强：对于含Nb(≥0.06%,质量分数,下同）较低的合金,“Snoek阻尼温区”（室温-150℃）内耗增强显著,其Snoek峰高温支明显抬起、甚至形成混合双峰;对于含Nb≤0.3%的合金,hs增强甚微,仍是一对称的Snoek峰,并在80－130℃间形成－分立峰。降温SKK峰向低温移动,但峰高(hSKK^c)未减低,含Nb较低合金的hSKK^c都明显高于hSKK^h。     

铈对Al—Mg—Si合金材料使用性能的影响

本工作研究了六种含Ce最不同的Al-Mg-Si合金型材的使用性能。结果表明,铈不仅能够提高该合金淬火人工时效状态型材的强度和塑性,同时不降低导电性能。但是,含Ce量高于0.05％时,随其含量增加而降低抗腐性能。     

Fe—Cr—Mn耐热合金的热分析研究

用热分析法测定了不同含Mn,C量的Fe-20％Cr-Mn合金的液相线温度和共晶转变温度,通过回归分析得到不同含C量的Fe-Mn准二元相图(凝固区间部分),分析了含Mn量对Fe-20％Cr-Mn合金液相线和共晶转变温度的影响。     

氢对Al—Li合金8091—T6疲劳寿命和断裂行为的影响

本文研究了氢含量对Ａｌ－Ｌｉ合金８０９１－Ｔ６薄板光滑试样疲劳寿命（Ｎｆ）、变形机制和断裂模式的影响。结果表明，合金的氢含量由１．０４３降低到０．０５３μｇ／ｇ，为成超低氢合金。Ｎｆ提高约一倍，疲劳变形机制由切割机制转变为绕过机制，断裂模式由以穿晶脆性断裂为主转变为穿晶韧性断裂，由氢脆引起的低韧性断裂特点完全消失。本文还简要地讨论了氢含量变化造成疲劳变形机制和断裂模式转变的原因。     

钕、钇对镁-锌-锆系变形合金时效行为的影响及对含钇合金强化机理的探讨

前言众所周知,Mg-Zn-Zr系变形镁合金是国内外镁合金中室温强度较高、综合性能好、应用范围广的结构合金,其中以MB15为代表。用稀土元素对Mg-Zn-Zr系合金进行附加合金化,可进一步提高合金的室温抗拉强度、屈服强度和高温瞬时强度。以MB15为例,分别添加钕(以下简称含钕合金)和钇(以下简称含钇合金),可使原MB15合金强度提高20—50兆帕,而耐蚀性能、工艺性能、焊接性能基本上不变。本文通过一系列试验,并与MB15对     

EFFECT OF Y ON MECHANICAL PROPERTIES OF Fe-20Cr-4Al-Y ALLOY

With the increase of Y content in the Fe-20Cr-4AI-Y alloy,the uniform deformability oftensile specimens was found to be slightly decreased,as well as,the fracture strength and re-duction after necking remarkably dropped.This seems to be dependent upon the brittle phasecontaining Y.The behaviour of Y-containing phase may be improved by adjusting themetallurgical technological process.     

稀土元素Y对Ti(C,N)基金属陶瓷性能的影响

研究了稀土元素 Y对 Ti(C,N)基金属陶瓷微观组织和性能的影响。 Y在 Ti(C,N)基金属陶瓷中可以起到净化粘结相 /硬质相界面的作用 ,并使其包覆层的厚度略有增加 ,从而使硬质相颗粒得到细化。当 Y含量为 0 .8wt%时细化效果最明显 ,此时 Ti(C,N)基金属陶瓷的抗弯强度和硬度值最大。     

YNi_5 PHASE AND ITS EFFECT UPON PROPERTIES OF Ni_3Al ALLOY

An additive of Y to Ni_3Al based alloy may form a phase YNi_5 which increases in amount withthe increase of Y content.It was found that the YNi_5 phase in Ni_3Al alloy could remarkablymake its grains finer and its grain boundaries more crooked other than straight.If the Y con-tent≥0.1 wt-%,it occurs as solid solution state and is favorable to high temperaturecompressive properties and oxidation resistance of the alloy.While Y≥0.3 wt-%,the forma-tion of YNi_5 is predominant in the shape of irregular strips inside Ni_3Al grains and alongtheir grain boundaries.This seems to be quite harmful to high temperature strength,ductilityand oxidation resistance of the alloy.     

MICROSTRUCTURES AND PROPERTIES OF RECIPROCATINGLY EXTRUDED Mg-6.4Zn-1.IY ALLOYS

An icosahedral Mg3 YZn6 quasicrystalline phase can be produced in Mg-Zn-Y system alloys when a proper amount of Zn and Y is contained, and it is feasible to prepare the quasicrystal phase-reinforced low-density magnesium alloy. In this article, phase constituents and the effect of reciprocating extrusion on microstructures and properties of the as-cast Mg-6.4Zn-1.1 Y alloy are analyzed. The microstructure of the as-cast Mg-6.4Zn-1.1 Y alloy consists of the a-Mg solid solution, icosahedral Mg3 YZn6 quasicrystal, and Mg3 Y2Zn3 and MgZn2 compounds. After the alloy was reciprocatingly extruded for four passes, grains were refined, Mg3 Y2 Zn3 and MgZn2 phases dissolved into the matrix, whereas, Mg3YZn6 precipitated and distributed uniformly. The alloy possesses the best performance at this state; the tensile strength, yield strength, and elongation are 323.4 MPa, 258.2 MPa, and 19.7%, respectively. In comparison with that of the as-cast alloy, the tensile strength, yield strength, and elongation of the reciprocatingly extruded alloy increase by 258.3%, 397.5%, and 18 times, respectively. It is concluded that reciprocating extrusion can substantially improve the properties of the as-cast Mg-6.4Zn-1.1 Y alloy, particularly for elongation. The high performance of the Mg-6.4Zn-1.1 Y alloy after reciprocating extrusion can be attributed to dispersion strengthening and grain-refined microstructures.     

STRUCTURE OF SPUTTERED Co-Cr-Al-Y COATING

The phase composition of Co-30Cr-6Al-0.5Y coating deposited by planar magnetronsputtering as well as the effect of sputtering parameters on it have been investigated.Thesputtered coating is composed of hep ε-phase of fcc α-phase of Co solid solution with a mi-nority of β-CoAl intermetallic phase.The hcp ε-Co phase and the fcc χ-Co phase assumed a<100>and <110>preferred orientation respectively.Both the phase type and orientationextent depend on the sputtering parameters.If the substrate surface is parallel to the targetface during sputtering,the coating will be of fine crystallite with compact structure andsmooth surface;if it is rotated,the coating will be to the contrary.     

EQUILIBRIUM OF Y-S-O IN LIQUID Ni

由低温无水电解稀土夹杂物和固体电解质定氧活度测得Ni液中钇的脱硫氧常数与温度的关系:lgKr_2o_2s=-(33146)/T+3.85,(1500-1600℃)钇的硫氧化物在Ni液中的标准生成自由能与温度的关系:2[Y]+2[O]+[S]=Y_2O_2S_(s),(1500—1600℃)△G°=151640+17.61T(cal/mol)=-634460+73.69T(J/mol)由实验测得数据经热力学分析计算得到1600℃Ni液中[Y]-[S]-[O]平衡立体图及α_o-α_s平衡相图,为理论上预测夹杂物生成的先后次序及类型提供了依据.并给出了Ni液中加钇控制夹杂物形态公式,钇的加入量与氧,硫含量之间的函数关系.     

Si和Y掺杂对(Ti,Al)N涂层结构和性能的影响

分别在未施加偏压和施加-100 V偏压条件下,利用磁控溅射技术在压气机叶片用1Cr11Ni2W2MoV热强不锈钢基体上沉积了Ti_0.3Al_0.7N和Ti_0.39Al_0.55Si_0.05Y_0.01N硬质涂层.实验结果表明,施加偏压及Si和Y掺杂明显改变了涂层的相结构,提高了涂层致密度,施加-100 V偏压且添加Si和Y的涂层为非晶结构,表面更加均匀致密.950℃氧化实验表明:Ti_0.39Al_0.55Si_0.05Y_0.01N涂层表面形成极薄且致密的Al₂O₃保护性氧化膜,大大降低了氧化速率.施加-100 V偏压的（Ti,Al）N和（Ti,Al,Si,Y）N沉积态涂层与未施加偏压的相应涂层相比,硬度均降低,尤其是（Ti,Al,Si,Y）N涂层变化显著.经950℃热处理,施加偏压的（Ti,Al,Si,Y）N涂层硬度略有降低,这是由于形成了硬度较低的B4相,而未施加偏压的（Ti,Al,Si,Y）N涂层硬度显著提高,这归因于B1相固溶体的分解.划痕测试结果表明,在实验载荷（50N）下,所有涂层均未出现连续性的剥落.     

METASTABLE EXTENSION OF SOLID SOLUBILITY OF RARE-EARTH ELEMENTS IN Al

The splat folis of Al-RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er and Yb)binary alloys of 0.04—0.06 mm thickness were made by are-melting and hammer-anviltechnique,the.cooling rate is in 10~6 K/s order of magnitude.The metastable extendedsolid solubilities of these RE elements have been evaluated by measurements of the latticespacings of the rapidly solidified(RS)Al-RE alloys,they are 0.4,0.15,0.21,0.21,0.3,0.5,0.1,0.6,0.65,0.7,0.75,0.2 at.-% for above individual RE clements,respectively.Thesecondary phase in RS Al-RE alloys were identified to be Al_4RE for alloys containinglight RE and Eu elements and Al_3 RE for alloys containing heavy RE and Y elements.Some factors influencing the extension of solid solubility of Al-RE alloy were discussed.     

EFFECT OF NANOCRYSTALLIZATION ON THE SCALING OF NiAl AT 1000℃ IN AIR

The oxidation behavior of a magnetron sputtered nanocrystalline NiAl coating was investigated at 1000℃ in air. Comparing with cast NiAl and NiAl-0.1at.%Y alloys reveals influences of nanocrystallization as well as yttrium addition on the oxidation behavior of NiAl. Results show that a phase transformation from metastable θ-Al2O3 to stable a-Al2O3 occurred in scales, which was accelerated by the microcrystallization and retarded by the addition of Y. The addition of Y as well as the nanocrystallization reduced the void formation at the interface between the scale and the substrate.     

稀土元素在Al中固溶度亚稳扩展研究

采用锤—砧技术制备了厚0.04—0.06mm快速凝固Al—RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er,Yb)合金箔试样,冷却速度达10~6K/s,用点阵参数法测得上述稀土元素在Al中亚稳扩展固溶度分别为0.4,0.15,0.21,0.21,0.3,0.5,0.1,0.6,0.65,0.7,0.75和0.2at.—%测定了Al—轻稀土(包括Eu)系中第二相是Al_4RE;Al—重稀土(包括Y)系中第二相是Al_3RE,原子尺寸因素是控制RE在Al中固溶度亚稳扩展的主要因素。