稀土变质处理对提高FCB合金组织韧性的研究

针对FCB合金韧性不足的问题,研究了采用稀土变质处理的方法来改变硼化物在晶界的分布状态提高FCB合金韧性的措施.实验结果表明:稀土变质剂对FCB合金具有明显的变质作用.加入5％稀土变质剂后,合金中网状的耐磨硼化物转变为断网状或球团状,甚至颗粒状,细化了合金组织,韧性显著提高.     

变质处理对ADC12铸造铝硅合金组织及性能的影响

借助金相显微分析实验、拉伸实验等手段,研究不同含量的Al-10Sr变质剂对ADC12铸造铝硅合金组织及性能的影响,结果表明:添加变质剂后,ADC12合金的显微组织得到明显的细化,抗拉强度及延伸率得到极大提高,其中当采用w(Sr)为0.06％进行变质处理时其效果最佳.     

铸造Al—Si合金变质处理的概况和发展趋势

综述了目前常用铸造Al-Si合金变质处理方法、特点，并介绍了各变质处理方法的发展概况及最新研究成果，认为含稀土元素的变质和复合变质是变质处理的发展趋势。     

两步法变质处理Zn-6Al合金的显微组织和力学性能研究

采用Al-5Ti-B对Zn-6Al合金进行两步法变质处理,运用扫描电镜（SEM）、能谱仪（EDS）和万能试验机分析测试了变质处理前后Zn-6Al合金的凝固组织和力学性能。结果表明：当加入0.50%的Al-5Ti-B时,随着高温变质熔体占比的增加,Zn-6Al合金中初生β-Al相面积分数不断增加,共晶组织层片间距先减小再增加;Zn-6Al合金的抗拉强度与屈服强度不断增加,延伸率先增加后降低;当高温变质熔体与低温熔体质量比为2∶3时,Zn-6Al合金的综合力学性能最佳。当高温变质熔体与低温熔体质量比为2∶3时,随着Al-5Ti-B加入量的增加,Zn-6Al合金中初生β-Al相面积分数、抗拉强度、屈服强度和延伸率呈现先增加再降低的变化趋势,共晶组织则呈现先细化再粗化的变化趋势。与未进行变质处理的Zn-6Al合金相比,当高温变质熔体与低温熔体质量比为2∶3和Al-5Ti-B加入量为0.75%时,Zn-6Al合金的抗拉强度、屈服强度和伸长率分别增加24%, 13%和118%。采用Al-5Ti-B对Zn-6Al合金进行两步法变质处理,可明显提高Zn-6Al合金的综合力学性能。     

含铈化学镀 Co-Ni-B 合金镀覆工艺的研究

研究了Ce加入化学镀钴镍硼合金的工艺。在正交试验的基础上分析了镀液组成对沉积速度的影响,综合考察了镀层表面质量及镀层与基体的结合力。结果表明在化学镀钴镍硼合金的工艺中,Ce加入后,镀液的稳定性、沉积速度和镀层质量能明显提高,并由此得出含Ce化学镀Co-Ni-B镀覆工艺的最佳镀液组成和操作条件。     

高温合金中微量铈的快速测定

采用DBC-偶氮胂[3-(2-胂酸基苯偶氮)-6-(2，6-二溴-4氮苯偶氮)-4，5二经基2，7-萘二磺酸]直接测定高温合金钢中微量铈和碳钢、低合金中的铈，获得满意结果。     

Al-La过共晶合金的组织特征及力学性能

采用真空熔炼方法,在石墨铸型中制备了过共晶合金Al-30%La、Al-35%La和Al-40%La试样,研究了它们的组织形貌特征和力学性能,发现过共晶合金Al-30%La、Al-35%La和Al-40%La中的枝晶是不连续的,其中Al-35%La中的Al11La3是周期性双相枝晶。力学性能测试结果表明,过共晶合金Al-30%La、Al-35%La和Al-40%La的抗拉强度较低,但抗压强度较高,并具有一定的相对压缩率(7.06%~15.11%);由硬度测试结果可知,随La含量的增加,Al-La合金的硬度随之增大,但合金Al-35%La的硬度呈现出一个低谷。     

Microstructure and Room Temperature Tensile Properties ofFe_3Al－based Alloys with Cerium Addition

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Solidification Microstructure and Mechanical Properties of Cast Magnesium-Aluminum-Tin Alloys

The solidification microstructure and mechanical properties of as-cast Mg-Al-Sn alloys have been investigated using computational thermodynamics and experiments. The as-cast microstructure of Mg-Al-Sn alloys consists of α-Mg, Mg₁₇Al₁₂, and Mg₂Sn phases. The amount of Mg₁₇Al₁₂ and Mg₂Sn phases formed increases with increasing Al and Sn content and shows good agreement between the experimental results and the Scheil solidification calculations. Generally, the yield strength of as-cast alloys increases with Al and Sn content, whereas the ductility decreases. This study has confirmed an early development of Mg-7Al-2Sn alloy for structural applications and has led to a promising new Mg-7Al-5Sn alloy with significantly improved strength and ductility comparable with commercial AZ91 alloy.     

Y含量对Mg-Zn-Y合金显微组织及力学性能的影响

采用金相显微镜、扫描电子显微镜、X-射线衍射仪以及电子万能实验机等设备,研究了Y对Mg-2Zn-xY（X=0、0．5、1、3,质量分数／％）舍金的显微组织及力学性能的影响。结果表明：随着Y含量的增加,合金二次相由Ⅰ相＋W相转变为W相＋H相。舍金力学性能随Y加入量的增加而提高,当加入量为1％时,合金的力学性能达到最佳：抗拉强度达到207MPa,伸长率达到16．9％;而加入量为3％时,综合力学性能又有所下降。     

稀土元素Sm对Mg-Zn-Y合金组织结构和力学性能的影响

制备了Mg-6Zn-1.5Y-0.8Zr-xSm(x=0,1,2,3)系列合金,研究了稀土元素Sm对Mg-6Zn-1.5Y-0.8Zr合金组织结构和力学性能的影响.通过金相显微镜、扫描电镜、EDS、XRD等观察和分析了合金的微观形貌和组织结构,测量了合金抗拉强度、屈服强度和伸长率等力学性能.结果表明:合金中添加稀土元素Sm后晶粒有了明显的细化,随着Sm元素含量的增加,晶粒细化效果更为明显;通过XRD分析,添加Sm元素后,合金中并没有出现新的含Sm的物相,通过扫描电镜和EDS分析表明,合金中加入的Sm置换了部分Y,形成了Mg3( SmY)2 Zn3,Mg3( SmY) Zn6的相结构,Sm元素对Y的置换主要出现在Mg3( SmY) Zn6结构当中,在Mg3 (SmY) Zn6相结构出现较少;力学性能测试结果表明,随着Sm含量增多,合金晶粒细化,细晶强化作用明显,合金屈服强度逐渐增大,而抗拉强度和伸长率在Sm含量为2％时达到最大,比未添加Sm元素时提高约15％以上.     

Mechanical Properties and Microstructure of Argon Atomized Aluminum-Lithium Powder Metallurgy Alloys

Aluminum-lithium and aluminum-copper-lithium alloy powders were prepared by argon gas atomization. The powders were consolidated by hot pressing and extruded into flat bar. Tensile and impact properties were determined on the extrusions. Transmission electron microscopy was used to examine the extruded microstructures while scanning microscopy was used for the examination of fracture surfaces. The aluminum-lithium alloys showed higher moduli, lower densities, and reduced toughness and elongation compared to conventional aluminum alloys. The loss of toughness was particularly pronounced above 3 pct Li.     

含Cu镁锂合金组织与性能调控研究进展

镁锂合金具有超低密度、极高的比强度与比刚度、优异的电磁屏蔽性能及阻尼性能,目前广泛应用于追求轻量化的航空航天、新能源汽车、电子产品、生物医疗等领域。由于合金元素镁和锂均为活泼金属,在服役过程中镁锂合金会存在多种形式的腐蚀过程,同时二元镁锂合金强度较低,以上两点严重制约了其广泛应用。耐蚀涂层可以有效提高镁锂合金的腐蚀抗力,含铜镀层被证实能够提升镁锂合金耐蚀性。改善镁锂合金强度的工艺主要有合金化、热处理、加工变形等,其中合金化是最基本的强化手段。Cu合金化可以对镁锂合金中的组织与性能进行调控,改善镁锂合金的强度。本文对含Cu镁锂合金的研究进展及其应用情况进行综述,总结了目前含Cu镁锂合金耐蚀与力学性能的相关研究成果,重点梳理了铜元素在镁锂合金中的作用,为含Cu镁锂合金的实际应用提供一定的理论指导。     

The Sintering, Sintered Microstructure and Mechanical Properties of Ti-Fe-Si Alloys

A systematic study has been conducted of the sintering, sintered microstructure and tensile properties of a range of lower cost Ti-Fe-Si alloys, including Ti-3Fe-(0-4)Si, Ti-(3-6)Fe-0.5Si, and Ti-(3-6)Fe-1Si (in wt pct throughout). Small additions of Si (??1?pct) noticeably improve the as-sintered tensile properties of Ti-3Fe alloy, including the ductility, with fine titanium silicides (Ti₅Si₃) being dispersed in both the ?? and ?? phases. Conversely, additions of ?>1?pct Si produce coarse and/or networked Ti₅Si₃ silicides along the grain boundaries leading to predominantly intergranular fracture and, hence, poor ductility, although the tensile strength continues to increase because of the reinforcement by Ti₅Si₃. Increasing the Fe content in the Ti-xFe-0.5/1.0Si alloys above 3?pct markedly increases the average grain size and changes the morphology of the ??-phase phase to much thinner and more acicular laths. Consequently, the ductility drops to <1?pct. Si reacts exothermically with Fe to form Fe-Si compounds prior to the complete diffusion of the Fe into the Ti matrix during heating. The heat thus released in conjunction with the continuous external heat input melts the silicides leading to transient liquid formation, which improves the densification during heating. No Ti-TiFe eutectoid was observed in the as-sintered Ti-Fe-Si alloys. The optimum PM Ti-Fe-Si compositions are determined to be Ti-3Fe-(0.5-1.0)Si.     

Ti和Ag元素添加对Cu-Cr系合金微观组织及力/电性能影响研究

以Cu-0.5Cr和Cu-0.5Cr-0.1Ti-0.1Ag合金为实验材料,研究同时添加Ti和Ag元素对Cu-Cr系合金微观组织及力/电性能的影响。结果表明,Cu-0.5Cr和Cu-0.5Cr-0.1Ti-0.1Ag两种合金在450 ℃×1 h退火时达到峰时效状态,且Ti和Ag元素的加入显著提高了Cu-Cr系合金的硬度,但导电性能有所降低。同时研究了两种合金的高温抗软化行为,发现软化过程伴随着晶粒回复和再结晶,Ti和Ag元素的添加提高了Cu-Cr系合金的再结晶活化能,延缓了软化过程中合金的再结晶过程,使得Cu-0.5Cr-0.1Ti-0.1Ag合金的抗软化温度比Cu-0.5Cr合金提高约25 °C。     

Investigation of Mechanical Properties of High-Density Iron-Based Alloys with Nanosized Additions

Metallurgist - Detailed analysis is provided for results of studying mechanical properties of alloys based on iron and nanodispersed particles of nickel oxide, copper oxide, and silicon nitride...