钛合金β固溶体价电子结构与合金元素的作用机制

基于固体与分子经验电子理论,计算分析了钛合金β固溶体的价电子结构,进而从电子结构层次分析了合金元素对钛合金固相转变的影响。研究发现,含某种合金元素的β固溶体的最强共价键上的共价电子对数nA值越大,该元素的固溶强化作用越强;nA值越大,β固溶体最强键越难断裂,α/(α+β)固相转变温度越低;反之,α/(α+β)固相转变温度越高;共价电子密度ρc值越大,β固溶体越稳定,(α+β)/β固相转变的温度越低;反之,(α+β)/β固相转变的温度越高,ρc越大,nA越小,β固溶体的(α+β)两相区越窄;反之,ρc越小,nA越大,(α+β)两相区越宽。     

Ar-H_2混合气体对硅铝合金熔体精炼除硼机制的影响（英文）

提出了一种将硅铝合金化与吹气精炼复合提纯冶金级硅的方法。在合金熔体Ar-H2_吹气精炼过程中,对硅中杂质相,尤其是硼和铁的形态及转变进行了分析和表征,并对除硼机制进行了讨论。实验结果表明:合金吹气(Ar-H_2)精炼可以有效去除硅中的硼元素,细化初晶硅颗粒和增加形核点的数量,这有利于杂质元素的扩散迁移。与未通气合金样品相比,经过2.5 h吹气精炼,硼的去除率由45.83%提高到74.73%。含硼杂质相主要是Ti B_2、Al B_2和VB金属间化合物,含铁杂质相主要是β-Al_5Fe Si金属间化合物。同时,硅中部分硼与溶解的[H]结合以B_xH_y(BH,BH_2)形式在电磁搅拌作用下,由合金熔体内部扩散到表面挥发,达到除硼的目的。     

铝-硼及铝-钛-硼中间合金的研制(上)

在理论计算的基础上,在实验室内分别研究了 B_2O_3及 B_2O_3和 TiO_2同时在铝电解槽中的热还原和电析出。在正常电解条件下,只要适当地控制电解质中 B_2O_3和 TiO_2的含量,不但可控制铝-硼合金中B 的含量及铝-钛-硼合金中 Ti 和 B 的含量,还可控制铝-钛-硼合金中 Ti 与 B 之比。这种合金可直接做铝及各种铝合金晶粒细化剂的中间合金。本文所研究的电解质体系与工业铝电解质成分和技术条件相似。研究结果对在工业电解槽中直接生产铝-硼及铝-钛-硼合金有着重要的参考价值。     

Ti—6Al—4V合金相变点的测定值与计算值的比较—计算相变点的经验公式

采用T=36.30E+613.64(E为合金元素和主要杂质铁、氧含量之和)经验公式计算Ti-6Al-4V合金的相变点,在本厂生产条件下,其计算值与实测值之差不超过±10℃。     

NOTE ON B AND M_3B_2 IN A NiFeCrWMoTiAl ALLOY

在NiFeCrWMoTiAl合金断口的萃取碳复型上,观察到:合金中的硼可以减少和消除能脆化合金晶界的Ti_4C_2S_2脆性薄片;硼含量为0.025—0.050％和0.075—0.100％时,M_3B_2分别呈薄片(或枝晶薄片)状和块状;在1200℃以下温度加热时,颗粒状M_3B_2沉淀,而且薄片状M_3B_2向颗粒状M_3B_2转变。     

NiFeCrWMoTiAl合金中的硼和M_3B_2

在NiFeCrWMoTiAl合金断口的萃取碳复型上,观察到:合金中的硼可以减少和消除能脆化合金晶界的Ti_4C_2S_2脆性薄片;硼含量为0.025—0.050％和0.075—0.100％时,M_3B_2分别呈薄片(或枝晶薄片)状和块状;在1200℃以下温度加热时,颗粒状M_3B_2沉淀,而且薄片状M_3B_2向颗粒状M_3B_2转变。     

微量硼元素的添加对AlCoCrFeNi多主元合金显微组织和性能的影响（英文）

研究微量硼元素对AlCoCrFeNiBx(x=0,0.01,0.02…0.09,0.10,x为摩尔分数)高熵合金微观组织和性能的影响。AlCoCrFeNi高熵合金呈现典型的等轴晶结构,晶内伴随着明显的成分偏析。然而,随着硼元素的添加,合金呈现明显的树枝晶结构。在树枝晶内可以观察到典型的调幅分解结构。晶体结构也随着硼元素的增加由B2+BCC结构转变为B2+BCC+FCC的混合结构;合金硬度呈先升后降趋势,由HV 486.7升高至HV 502.4,最后降低至HV 460.7;压缩断裂强度在x=0.08前呈上升趋势,之后呈下降趋势;合金呈软磁性,其矫顽力和饱和磁化强度均随着硼元素含量增加而下降,表明硼元素对合金软磁性有提高作用。     

CRYSTALLOGRAPHY OF MARTENSITIC TRANSFORMATION IN A Cu-26Zn-4Al SHAPE MEMORY ALLOY Ⅰ. Experimental and Phenomenological Theory

本文以马氏体相变晶体学表象理论讨论了Cu-26Zn-4Al形状记忆合金马氏体相变的晶体学性质,采用B_2(CsCl)结构→非规则9R单斜晶胞的应变矩阵,用计算机求得该合金马氏体相变的晶体学结果。该合金马氏体惯析面为(1,7.71,9.32),与实验测得的惯析面(1,7,8)相差1.6°,两者吻合较好。     

单晶高温合金杂晶形成倾向性数值模拟

采用液态金属冷却法(LMC)实现定向凝固,运用ProCAST有限元软件包计算了DD483高温合金的定向凝固过程。在试验验证获得合理模拟参数的基础上,模拟抽拉速度和平台尺寸对高温合金变截面试样定向凝固过程温度场的影响,并采用ProCAST中的元胞自动机(CA)与有限元(FE)耦合模块计算相应条件下的微观组织,探究拉速和平台尺寸对高温合金变截面试样平台区域杂晶形成的影响。结果表明,冷却曲线模拟结果与试验结果吻合良好;拉速越大,杂晶形成倾向越大;同样,平台尺寸越大,杂晶形成倾向也越大;试样平台尺寸越大,获得单晶的临界拉速越小。     

氢在合金熔体中的溶解度计算(英文)

基于氢在纯金属中的溶解度数据以及合金之间的相互作用系数,提出氢在合金熔体中溶解度的热力学计算模型。计算结果与文献中的实验数据吻合得很好。结果表明,合金熔体的性质越接近理想溶液,计算结果越准确,合金元素形成化合物的能力及其摩尔混合热对氢在合金熔体中的溶解度有重要影响。     

RANGE PARAMETERS IN METALS AND ALLOYS

The formulae for calculating the electronic stopping power.for heavy ion implanting into metalare derived by using Wigner-Sietz radius r_s,equivalent charge,Fermi velocity and Ziegler'svalues of hydrogen electronic stopping power.Meanwhile the.formulae of electronic stoppingpower S_e(E)for alloys with boride or CsCl structure are also proposed.The calculated resultsare found as follows:these formulae are suitable only for mono-or bi-borides,but not forborides with more complex structure such as Cr_5B_3 or W_2B_5;the coefficient γ,of S_e(E)for al-loys with CsCI structure deviating from Bragg's S_e(E)is directly proportional to charge trans-fer in alloy.This means the larger the charge transfer is,the more stronger the metallic bondis.Hence the S_e(E)created by metallic bond in alloys will increase; there is a tendency for it toincrease with increasing separation of two components in alloy on either side of Cr group atsame periods,when the two components are in different periods,the tendency is more larger.     

硼化物对镁合金净化效果影响的研究

对含硼化物B2O3或Na2B4O7的镁合金净化熔剂进行研究,比较粘度及其对镁合金的净化效果.硼化物熔剂处理镁合金液后,铁含量有大幅度降低,夹杂也有明显减少.镁合金的抗腐蚀性能和力学性能得到提高.但是含B2O3熔剂较高的粘度使其净化效果相对较差.     

净化对非晶形成能力和非晶热稳定性的影响SCIEI

采用玻璃熔体净化法和电磁悬浮循环过热法消除Ni_(75),B_(17)Si_R合金液内的异质核心,研究了净化对该合金液非晶形成能力和所形成的非晶合金热稳定性的影响。采用净化和忽冷相结合的工艺制备出了20×10×0.5mm的Ni_(75)B_(17)Si_8非晶试样,试样的厚度较净化前提高了4倍。     

块状非晶合金CU-Zr-Ti-Sn在3.5%NaCl溶液中的腐蚀行为

利用电化学极化曲线方法和电化学阻抗谱(EIS)技术研究了Cu60Zr30Ti10和(Cu60Zr30Ti10)99Sn1块状非晶合金及其晶化后在3．5％NaCl溶液中的腐蚀行为．极化曲线测试结果表明，(Cu60Zr30Ti10)99Sn1非晶合金在3．5％NaCl溶液中的阳极极化衄线有一定的钝化倾向，且其阳极电流密度较Cu60Zr30Ti10非晶合金的阳极电流密度有所降低；同时EIS结果显示，其电化学反应电阻Rt较Cu60Zr30Ti10的Rt值有所增大，说明添加1％Sn使非晶合金Cu60Zr30Ti10的耐蚀性能有所改善．相应成分晶化后的合金与非晶合金的极化曲线相比较，阳极极化表现出较大的钝化倾向，且阳极电流密度略有降低．晶化后合金的EIS测试显示有两个时间常数，即由高频容抗弧和低频容抗弧构成．晶化后合金与其非晶合金相比较，电化学反应电阻见明显增大，表明晶化后合金的耐蚀性能有所提高。     

EFFECT OF Cr,Cu AND Co ON MAGNETOSTRICTION OF Fe-Si-B AMORPHOUS ALLOYS

The dependence of composition varied,especially C,Si,Cr,Cu and Co in four amorphousalloy systems Fe_(80-x)Cr_xSi_5B_(15).Fe_(80-x)Cr_xC_5B_(15).Fe_(80-x)Cu_xSi_5B_(15)and(Fe_(1-x)Co_x)_(82)Cu_(0.4)Si_(4.4)B_(13.2)upon their saturation magnetostriction at room temperature hasbeen studied.It was observed that the saturation magnetostriction of the alloys may be re-markably improved by small addition of Cu and Co.the peak value being up to 70×10~(-6)asx=0.02 in alloys(Fe_(1-x)Co_x)_(82)Cu_(0.4)Si_(4.4)B_(13.2).     

Cr,Cu,Co对Fe—Si—B非晶合金磁致伸缩系数的影响

本文报道了Fe_(80-x)Cr_xSi_5B_(15),Fe_(80-x)Cr_xC_5B_(15),Fe_(80-x)Cu_xSi_5B_(15)和(Fe_(1-x)Co_x)_(32)Cu_(0.4)Si_(4.4)B_(13.2)四系列非晶合金在室温下的饱和磁致伸缩系数λs随成分x的变化关系,讨论了C,Si,Cr,Cu,Co原子对磁致伸缩系数的影响。发现少量Cu,Co的加入大大提高了非晶合金的λs。特别是(Fe_(1-x)Co_x)_(82)Cu_(0.4)Si_(4.4)B_(13.2)系列中当x=0.02时峰值λs=70×10~(-6)。     

Investigation on mechanical properties of aluminium 7075-boron carbide-coconut shell fly ash reinforced hybrid metal matrix composites

The present research work reports the fabrication and evaluation of the mechanical properties of hybrid aluminium matrix composites(HAMC). Aluminium 7075(Al7075) alloy was reinforced with particles of boron carbide(B_4 C) and coconut shell fly ash(CSFA). Al7075 matrix composites were fabricated by stir casting method. The samples of Al7075 HAMC were fabricated with different weight percentages of(0, 3, 6, 9 and 12 wt.%) B_4 C and 3 wt.% of CSFA. The mechanical properties discussed in this work are hardness, tensile strength, and impact strength. Hardness of the composites increased 33% by reinforcements of 12 wt.% B_4 C and 3 wt.% CSFA in aluminium 7075 alloy. The tensile strength of the composites increased 66% by the addition of 9 wt.% B_4 C and 3 wt.% CSFA in aluminium 7075 alloy. Further addition of reinforcements decreased the tensile strength of the composites. Elongation of the composites decreased while increasing B_4 C and CSFA reinforcements in the matrix. The impact energy of the composites increased up to 2.3 J with 9 wt.% B_4 C and 3 wt.% CSFA addition in aluminium alloy. Further addition of reinforcement decreased the impact strength of the composites. The optical micrographs disclosed the homogeneous distribution of reinforcement particles(B_4 C and CSFA) in Al7075 matrix. The homogeneously distributed B_4 C and CSFA particles added as reinforcement in the Al7075 alloy contributed to the improvement of hardness, tensile strength, and impact strength of the composites.     

汽车发动机冷却液中镁合金缓蚀剂的研究

采用XRD、电化学极化曲线、化学浸泡等实验方法，研究了腐蚀性水体系中单种无机盐、复配无机盐缓蚀剂对AZ91D镁合金的缓蚀作用，并用正交优化设计确定了Na2MoO4+Na2SiO3+KMnO4复配无机盐缓蚀剂的优化配方；研究了水-乙二醇（1：1）防冻液基础液体系中缓蚀剂对AZ91D镁合金的缓蚀作用.结果表明，在腐蚀性水中KMnO4、Na3PO4、Na2MoO4和NaF对AZ91D镁合金有一定的缓蚀作用，Na2B4O7不具有缓蚀作用，有可能加速其腐蚀；复配Na3PO4+KMnO4及Na2MoO4+Na2SiO3+KMnO4对AZ91D镁合金腐蚀有缓蚀作用，而Na3PO4+Na2B4O7会加速其腐蚀.在水-乙二醇体系中，Na2S对AZ91D镁合金腐蚀有较好的缓蚀作用；确定了2种适用于水-乙二醇中的有机-无机复合缓蚀剂配方，缓蚀效率分别为98.1％和94.3％.     

不合格金属氧化物的退除方法

总结近年来在金属氧化物退除方面的进展;简略地介绍不锈钢、铝合金、铜合金、镁合金以及铅、锡、锌氧化膜的化学与电化学退除方法,并归结了34种配方.     

Microstructure and mechanical properties of Zr-Cu-Al bulk metallic glasses

Zr49Cu46Al5 and Zr48.5Cu46.5Al5 bulk metallic glasses（BMGs） with diameter of 5 mm were prepared through water-cooled copper mold casting. The phase structures of the two alloys were identified by X-ray diffractometry（XRD）. The thermal stability was examined by differential scanning calorimetry（DSC）. Zr49Cu46Al5 alloy shows a glass transition temperature, Tg, of about 689 K, an crystallization temperature, Tx, of about 736 K. The Zr48.5Cu46.5Al5 alloy shows no obvious exothermic peak. The microstructure of the as-cast alloys was analyzed by transmission electron microscopy（TEM）. The aggregations of CuZr and CuZr2 nanocrystals with grain size of about 20 nm are observed in Zr49Cu46Al5 nanocrystalline composite, while the Zr48.5Cu46,5Al5 alloy containing many CuZr martensite plates is crystallized seriously. Mechanical properties of bulk Zr49Cu46Al5 nanocrystalline composite and Zr48.5Cu46.5Al5 alloy measured by compression tests at room temperature show that the work hardening ability of Zr48.5Cu46.5A15 alloy is larger than that of Zr49Cu46Al5 alloy.