Mg-Zn系合金G.P.区和时效强化的研究进展

评述了国内外Mg-Zn系合金的研究进展.总结了Mg-Zn系合金中时效析出行为和各析出强化相的特征,通过分析铝合金G.P.区的形成规律,探讨了Mg-Zn系合金G.P.区的存在可能性.指出Mg-Zn系合金G.P.区的研究对Mg-Zn合金析出相变理论和发展高强度铗合金具有重要意义.     

Ti-Mn系贮氢合金研究

Ti-Mn系贮氢合金与其它实用的合金系相比,具有高的吸放氢量,好的平台特征,良好的吸放氢动力学性能和较低的成本,是有发展前景的贮氢合金系统之一。本文综述了目前对Ti-Mn二元系,三元系及多元系贮氢合金的贮氢与工程应用特性研究情况,并讨论了置换元素对Ti-Mn系合金的影响。     

铍铜替代用高性能铜基弹性合金的开发现状

高性能铜基弹性合金的开发是国内外铍铜行业普遍关注的焦点。本文概述了铍铜替代用高性能铜基弹性合金如Cu-Ti系、Cu-Ni-Sn系、Cu-Ni-Cr系、Cu-Ni-Mn系、Cu-Ni-Al系合金等的开发现状。指出了国内外在铍铜替代用高性能铜基弹性合金领域的研发及应用水平差距。     

稀土Mg-Gd系合金的研究现状与展望

Mg-Gd系镁合金因满足航空航天材料轻量化、高温强度的要求而受到极大关注。简述了稀土Mg-Gd系合金的研究现状。从合金氧化夹杂、流动性能、Gd在合金中的偏析以及合金的热裂性等方面阐述了浇铸法制备Mg-Gd系合金的铸造性能。通过统计比较了近年来在Mg-Gd基础上设计出的合金在不同状态下的强度、塑性数据。阐述了合金在低温、室温下的强度与抗蠕变性能、高温压缩性能和短时强度等高温力学性能及各自的断裂机制。最后,叙述了该合金系的耐腐蚀性能,并展望了该合金系的研究前景。     

Mg-Gd-Y合金的研究进展

已有的研究表明,Mg-Gd-Y系合金具有很好的室温强度和耐热性能,可以进一步扩大镁合金的使用温度范围和应用领域,在航空航天、汽车及电子等工业领域具有巨大的潜在应用价值.介绍了Mg-Gd-Y系合金产生的背景及发展现状,分析总结了Mg-Gd-Y系合金的强化机制、组织结构、力学性能、各种合金元素及微量元素在合金中的作用,并对Mg-Gd-Y系合金今后的发展趋势进行了展望.     

Mg-9Gd-4Y-0.6Zr合金在-196～400℃的断裂机制分析

用金相显微镜和扫描电镜对Mg-9Gd-4Y-0.6Zr合金在不同温度下的拉伸试样进行断口分析.结果表明合金在不同温度下启动的滑移系不同,引起合金的变形机制和断裂机制也不同.25℃时合金仅以基面进行滑移,可启动的滑移系少,合金的断裂机制为穿晶解理断裂;-196℃时棱柱面滑移系可能启动,导致滑移系数量增加,合金产生低温塑性现象,合金的断裂机制为微孔聚集型断裂;250,300,350℃时合金进入多系滑移阶段,基面、棱柱面和锥面的滑移系都能启动,合金的断裂机制也为微孔聚集型断裂;400℃时由于再结晶的发生,新再结晶的细晶能非常容易地进行晶界滑移变形,合金产生粗晶超塑性现象,合金的断裂机制为沿晶剪切断裂.     

Fe-Mn-Si系形状记忆合金研究近况

Fe-Mn-Si系形状记忆合金因其很好的可加工性和低廉的价格而备受关注.综述了该系形状记忆合金最近的研究工作,包括相变机制、影响因素,着重是提高和改善Fe-Mn-Si系合金性能的途径.主要通过选择合适的合金成分配比和摸索恰当的制备工艺来提高和改善Fe-Mn-Si系合金性能,叙述了该合金系不同合金元素和制备工艺对形状记忆效应的影响.     

Mg-Ni系储氢合金元素取代改性的研究进展

综述了对Mg-Ni系储氢合金进行元素取代改性的最新研究进展,分析了Mg-Ni系储氢合金A、B两侧元素的构成,并分别按Mg-Ni系中A、B两侧元素的性质,讨论了这些元素部分取代A2B型Mg2Ni和AB型MgNi合金中的Mg和Ni对Mg-Ni系合金储氢性能的影响。对近年来研究的多元Mg基储氢合金的充放氢性能和电化学性能进行了系统的阐述,总结了取代元素在降低Mg-Ni系储氢合金的氢化物生成热和放氢温度、提高合金电极循环寿命时的作用。     

多元铝基合金牺牲阳极研究

本文论述了采用正文设计试验方法对四种多元铝合金牺牲阳极的工作电位、电流效率、表面溶解等性能指标进行的室内试验研究。其结果是:Al-Zn-In-Mg-Ti系合金牺牲阳极的电化学性能最佳,Al-Zn-In-Mg-Sn-Si系合金次之,Al-Zn-In-Si-Ti系合金较差,Al-Zn-In-Mg-Ca系合金的电化学性能低劣,不可用作牺桂阳极。     

铸造Fe-Co-Mo系低工作场磁滞合金研究

一、前言 Fe-Co-Mo系合金在30年代初作为永磁材料曾经进行过研究、钼含量为15～18％的Fe-Co-Mo合金最佳磁性能达到矫顽力H_c=3500e,剩余磁感Br为7500G,然后在30年代初期Fe-Ni-A1系合金和稍后Fe-Ni-Co系合金的发展,其性能远超过Fe-Co-Mo系合金,因而使Fe-Co-Mo系合金作为永磁材料而未得到广泛应用。近十多年来,由于电气及电子工业的发展,在磁性材料中形成了一个新的领域,即半硬磁材料。它广泛用于磁滞电机的转子     

Influence of two-step ball-milling condition on electrical and mechanical properties of TiC-dispersion-strengthened Cu alloys

TiC-dispersion-strengthened Cu alloys were prepared by a two-step ball-milling (BM) process followed by sparks plasma sintering (SPS), heat treatment and hot rolling in sequence. The two-step BM process is composed of a pre-ball-milling (pre-BM) on both Ti and graphite powders as well as a subsequent homogenizing by BM together with Cu powder. Microstructure evolution analysis was performed to evaluate the effects of BM conditions on the electrical and mechanical properties of Cu-based alloys. The X-ray results revealed that titanium carbide (TiC) formed from Ti and C under high impact energy BM. Moreover, the formation of TiC during the SPS and heat treatment processes was found to more beneficial in enhancing the mechanical properties of alloy. The residual Ti in Cu matrix was found to be the predominant factor lowering the electrical conductivity of Cu–Ti–C alloys.     

Microstructure and Strength of Brazed Joints of Ti3Al Base Alloy with Cu-P Filler Metal

Brazing of Ti3AI alloys with the filler metal Cu-P was carried out at 1173-1273 K for 60-1800 s. When products are brazed, the optimum brazing parameters are as follows: brazing temperature is 1215-1225 K; brazing time is 250-300 s. Four kinds of reaction products were observed during the brazing of Ti3AI alloys with the filler metal Cu-P, i.e., Ti3AI phase with a small quantity of Cu (Ti3AI(Cu)) formed close to the Ti3AI alloy; the TiCu intermetallic compounds layer and the Cu3P intermetallic compounds layer formed between Ti3AI(Cu) and the filler metal, and a Cu-base solid solution formed with the dispersed Cu3P in the middle of the joint. The interfacial structure of brazed Ti3AI alloys joints with the filler metal Cu-P is Ti3AI/Ti3AI(Cu)/TiCu/Cu3P/Cu solid solution (Cu3P)/Cu3P/TiCu/Ti3AI(Cu)/Ti3AI, and this structure will not change with brazing time once it forms. The thickness of TiCu+Cu3P intermetallic compounds increases with brazing time according to a parabolic law. The activation energy Q and the growth velocity K0 of reaction layer TiCu+Cu3P in the brazed joints of Ti3AI alloys with the filler metal Cu-P are 286 kJ/mol and 0.0821 m2/s, respectively, and growth formula was y2=0.0821exp(-34421.59/T)t. Careful control of the growth for the reaction layer TiCu+Cu3P can influence the final joint strength. The formation of the intermetallic compounds TiCu+Cu3P results in embrittlement of the joint and poor joint properties. The Cu-P filler metal is not fit for obtaining a high-quality joint of Ti3AI brazed.     

钛增强Cu40Zn黄铜合金的粉末冶金制备及其力学性能

采用粉末冶金法将合金元素Ti加到Cu40Zn基体中制备钛黄铜,研究了Ti的添加量对黄铜微观组织、界面结构、相组成以及力学性能的影响。结果表明：Ti在基体中固溶析出并与Cu40Zn反应生成了亚微米级的Cu₂Ti₄O颗粒和Ti纳米团簇,随着Ti含量的提高钛黄铜的屈服强度、抗拉强度和硬度呈提高的趋势。增大位错运动阻力产生的第二相强化、钉扎产生的细晶强化以及加工硬化,使Cu40Zn的力学性能提高。综合性能良好的Cu40Zn-1.9Ti,其屈服强度、抗拉强度、延伸率和硬度分别达到375 MPa、602 MPa、17.7%和163HV。     

合金元素对Fe-Al-Cu合金的组织与性能的影响

研究了不同含量的钛、锰、硼及其交互作用对70.8Fe18.7Cu10.5Al(w/%)合金铸态组织与性能的影响。结果表明:合金由铁固溶体、铜固溶体及弥散分布于铁固溶体中的析出相组成。钛、硼的加入可细化结晶组织并提高合金的抗拉强度;加入适量的钛、锰、硼可使合金获得较好的综合力学性能。     

原位TiCP/Fe 复合材料组织中的有害相及其防止措施

研究了原位( in situ) TiCP/Fe 复合材料组织中有害相Fe₃C 和Fe₂Ti 的形成过程及其防止措施。结果表明:Fe₃C 和Fe₂Ti 均在Fe₂Ti₂C 熔体等温反应后的凝固过程中形成, 且与奥氏体中固溶的Ti 量有关; 对熔体进行微量Cu、Ni 合金化及孕育处理可促进熔体中TiC 颗粒的形成, 并有效地防止组织中有害相的产生, 从而使复合材料的性能得以进一步提高。      

微量Al添加对铜基大块非晶合金性能的影响

为了进一步提高铜基大块非晶合金的玻璃形成能力及力学性能,采用添加微量Al元素的方法对块体非晶合金Cu52.5Ti30Zr11.5Ni6进行了成分优化.热分析与X射线衍射结果显示,随着微量Al的添加,液相线温度从非晶合金Cu52.5Ti30Zr11.5Ni6的1150 K逐步降低到Cu50.5Ti30Zr11.5Ni6Al2的1134 K,临界直径相应的从5 mm提高到6 mm.大块非晶Cu50.5Ti30Zr11.5Ni6Al2的压缩断裂强度达到2286 MPa,比经典的铜基非晶合金Cu47Ti34Zr11Ni8提高约100 MPa,表明微量Al的添加在有效提高玻璃形成能力的同时,强度也略有提高.     

惯性导航仪用新型铸造铝合金研究

研究了惯性导航仪用新型Ａｌ－Ｚｎ－Ｍｇ系高尺寸稳定性铸造铝合金。新型合金为ＺＡｌＺｎ４Ｍｇ４，具有较高强度及良好的综合性能。研究了Ｚｎ、Ｍｇ、Ｃｕ、Ｔｉ及Ｚｒ等元素和热处理工艺对合金性能的影响，并测定了合金的物理性能和尺寸稳定性。     

Effect of Vacuum Heat Treatment on the Microstructure and Tribological Property of Ti–6Al–4V Alloy with Cu Coating

The effect of vacuum heat treatment on the interface microstructure and tribological property of Cu-coated Ti – 6Al – 4V alloy is investigated herein. After the vacuum heat treatment process, a diffusion layer is formed at the interface between the Cu coating and the Ti – 6Al – 4V substrate. The formed intermetallic compounds at the interface between the Ti – 6Al – 4V substrate and Cu coating are CuTi₂, CuTi, Cu₄Ti₃, and β-Cu₄Ti. The activation energy of intermetallic compound growth in the diffusion zone of Cu-coated Ti – 6Al – 4V is 126.0 kJ mol⁻¹, and the pre-exponential factor is 0.1 m² s⁻¹. The tribological properties of the Cu-coated Ti – 6Al – 4V alloy are best when subjected to diffusion treatment at 700 °C for 300 min, with weight loss reduced by 58.2% compared to the Ti – 6Al – 4V alloy. The wear resistance of the Ti – 6Al – 4V alloy can be enhanced by Cu coating and vacuum diffusion heat treatment, and the formation of the Cu – Ti intermetallic compound contributes to this improvement. These findings offer new insights for further advancements in the tribological properties of titanium alloys.     

(TiB2+Al2O3)增强铜基复合材料的研究

研究了Cu-Al-TiO2-B2O3粉末在机械合金化和随后的烧结过程中结构的变化，结果表明：Cu-Al-TiO2-B2O3粉末通过机械合金化可以形成Cu(Ti,B）及Al2O3和少量的TiCu3粉末，Al2O3是通过机械合金化过程中的自维持反应形成的，采用Cu,Al,TiO2和B2O3作为原料，通过机械合金化和随后的加压烧结，可以制备性能较好的（TiB2 Al2O3）增强铜基复合材料。     

Age hardening studies of a Cu–4Ti–Cr–Fe alloy

The microstructure, mechanical properties, and electrical conductivity (EC) of Cu–4Ti–Cr–Fe alloy aged at 773?K in vacuum are studied in this work. The results show that the multiple trace alloying elements have little effect on the microstructure evolution during the aging treatment at 773?K. However, with prolonged aging, the hardness, yield strength, and tensile strength first increase, then decrease. The Cu–4Ti–Cr–Fe alloys show superior hardness and strength performance than other alloys. In both the solid-solution treated and aged cases, the EC decreases if multiple trace alloying elements are added to the Cu–4wt-%Ti alloys, which indicates the CuTi intermetallic compound may have a large negative influence on the EC of copper alloy.