热变形温度对7085铝合金组织和性能的影响

对7085铝合金进行温度范围为350～450℃的恒应变速率热压缩实验,模拟其工业等温锻造过程。采用金相显微镜、扫描电镜、力学性能测试、剥落腐蚀测试以及应力腐蚀开裂(SCC)测试技术研究热变形温度对7085铝合金锻件的显微组织、力学性能、剥落腐蚀性能以及应力腐蚀性能影响。研究结果表明:在350和400℃下变形的合金在热压缩与压缩后缓冷过程中未发生再结晶,而在420和450℃下变形的合金再结晶迹象明显;7085变形态合金经固溶与时效处理后,合金时效态的再结晶程度以及平均晶粒尺寸随变形温度的升高而增大;7085合金时效态的室温强度随变形温度升高而减小,塑性降低不显著;不同温度变形的7085合金的断裂模式均为韧性断裂;随着变形温度的升高,7085合金T6态的抗剥落腐蚀与抗应力腐蚀性能降低。     

固溶热处理对AA7085铝合金组织与性能的影响

采用拉伸试验、电导率测试、剥落腐蚀试验、金相观察及透射电镜分析等方法,研究了不同固溶热处理工艺(包括常规固溶、高温预析出固溶与部分重固溶)对AA7085铝合金的强度、剥落腐蚀性能及显微组织的影响。结果表明,采用部分重固溶工艺并时效处理后,合金的抗拉强度降低,但电导率与抗剥落腐蚀性能明显得到提高。其原因是通过部分重固溶处理并时效处理后,合金中的晶界析出细小且非连续分布的η析出相,从而提高了AA7085铝合金的抗腐蚀性能。     

合金成分与热处理对6xxx系铝合金力学性能的影响

研究合金成分（Mg,Si,Cu）和热处理（自然时效和预时效）对6xxx系铝合金力学性能的影响。结果表明：合金成分与热处理不仅影响材料的成形性能,而且影响材料的烘烤硬化性能;提高合金中Si含量或Si／Mg比或添加0．3％Cu,可显著提高材料的韧性和成形性能,而预时效将减低材料的韧性和成形性能。对所研究合金的强度、韧性、加工硬化、应变敏感性、成形极限和烘烤硬化性进行了比较和总结。     

单级和双级固溶热处理对AA7085合金性能的影响

对AA7085铝合金进行单级和双级固溶处理,通过显微硬度测试和电导率测试,结合光学显微镜分析,研究了两种固溶处理方式对7085铝合金的性能和微观组织的影响.结果表明,与单级固溶相比,双级固溶处理使7085铝合金中的粗大第二相溶解的更充分,经时效处理后,具有更好的时效析出效果,合金的综合性能也更好.     

Sc、Zr对Al-Zn-Mg-Cu合金组织与性能的影响

制备了成分Al-5．8Zn-2．5Mg-1．6Cu-0．2Cr和Al-5．8Zn．2．5Mg-1．6Cu-0．2Cr-0．23Sc-0．12Zr的两种合金。通过金相显微镜及电镜观察、力学性能及腐蚀性能测试，分析了两种合金不同处理状态的显微组织及其不同状态下的力学性能和腐蚀性能。结果表明，添加Sc、Zr能显著细化合金的铸态组织，对合金的力学性能及腐蚀性能也起到极大的提高作用。添加Sc、Zr的2#合金与1#合金相比较，经T6处理后，前者的抗拉强度提高110N／mm^2，屈服强度提高91N／mm^2，伸长率也略有提高。     

合金元素含量对A7N01-T4铝合金微观结构与性能的影响

对A7N01铝合金的Zn、Mg、Zr、Ti、Cu元素含量进行设计,得到四种轧制板材,并进行自然时效。采用力学性能测试、金相组织观察以及腐蚀试验,研究了合金元素含量对A7N01-T4铝合金板材性能的影响。结果表明:Zr、Ti元素对合金显微组织中晶粒大小有较大的影响;Zn、Mg含量的提高可明显提高合金的强度,但高水平的Zn、Mg会降低合金的耐蚀性;微量Cu元素的添加有补充强化的作用,同时也能提高合金的耐蚀性。     

合金元素含量对A7N01-T4铝合金微观结构与能的影响

对A7N01铝合金的Zn、Mg、Zr、Ti、Cu元素含量进行设计,得到四种轧制板材,并进行自然时效.采用力学性能测试、金相组织观察以及腐蚀试验,研究了合金元素含量对A7N01-T4铝合金板材性能的影响.结果表明:Zr、Ti元素对合金显微组织中晶粒大小有较大的影响;Zn、Mg含量的提高可明显提高合金的强度,但高水平的Zn、Mg会降低合金的耐蚀性;微量Cu元素的添加有补充强化的作用,同时也能提高合金的耐蚀性.     

Ni元素对非晶合金Mg_(65)Cu_(25)Gd_(10)在NaCl溶液中腐蚀行为的影响

采用析氢腐蚀实验比较了非晶合金Mg65Cu25Gd10和Mg65Cu20Ni5Gd10在1%NaCl溶液中腐蚀性能。利用电化学测试技术和场发射扫描电子显微镜(FESEM)对两非晶合金在NaCl溶液中的腐蚀行为进行了研究。析氢腐蚀实验表明,Ni的加入大大提高了非晶合金Mg65Cu25Gd10抗蚀性能,极化曲线测试结果也表明Mg65Cu20Ni5Gd10非晶合金的腐蚀电流远远小于Mg65Cu25Gd10非晶合金。EIS测试表明,电化学阻抗谱测试结果显示Mg65Cu20Ni5Gd10非晶合金电荷转移电阻高于Mg65Cu25Gd10非晶合金。腐蚀产物形貌观察表明,Ni的加入使非晶合金Mg65Cu20Ni5Gd10腐蚀表面膜更为致密。结合各测试结果,探讨了Ni的加入提高镁基非晶合金耐蚀性机理。     

淬火工艺对含Sc的AA7150锻造铝合金性能的影响

采用熔炼铸造与锻造变形方法制备含0.3%Sc的AA7150铝合金。通过拉伸测试、剥落腐蚀测试、金相及透射电镜等技术方法,研究不同淬火工艺对锻造态铝合金性能及显微组织的影响。结果表明:铝合金在空气中自然冷却时,T6时效态合金的抗拉强度与抗剥落腐蚀性能层严重降低;而室温水淬的T6时效态合金比室温油淬的T6时效态合金具有更好的塑性。当预先采用(80℃,30s)水淬火或(80℃,30s)油淬火再15℃水淬时,T6时效态合金的抗拉强度明显得到提高,且抗剥落腐蚀性能也得到了改善。预先80℃淬火能提高T6时效态合金性能的主要原因是时效态合金晶界析出相的尺寸与离散度明显增大。     

微量Sc对AA7085铝合金组织与性能的影响

通过铸锭冶金工艺,制备含微量Sc的AA7085铝合金。采用金相观察、力学性能测试、扫描电镜及透射电镜分析,研究添加0.3%Sc对基体合金的铸态及锻造态的显微组织和力学性能的影响。结果表明,添加0.3%Sc能细化铸态合金的晶粒,抑制锻造态合金的再结晶,最终提高基体合金的强度和断裂韧性;含0.3%Sc的合金抗拉强度达到562MPa,断裂韧性KIC(S-L)达到34MPa·m1/2。含Sc的AA7085合金的强化机制主要是Al3(Sc,Zr)相引起的细晶强化、亚结构强化和沉淀强化。     

Cu含量对Al-2.5Mg-xCu-0.2Si合金微观组织和性能的影响

研究了Cu含量对Al-2.5Mg-x Cu-0.2Si合金微观组织和性能的影响。结果表明:由于形成Cu、Mg原子团簇,加入Cu的合金的显微硬度在时效初期有明显的快速硬化。随着时效时间的延长,由于S′相和GPB的形成使得合金的硬度再次提高,并达到硬度峰值。快速硬化的硬度值和峰值硬度值均随铜含量的增加而增加。铜含量增高,合金的抗拉强度和屈服强度增加明显,延伸率降低。含铜量增高,合金的抗晶间腐蚀能力变差。当Cu含量低于1.14%(质量分数,下同)时,合金具有良好的抗晶间腐蚀性能;但含铜2.10%的合金抗晶间腐蚀性能显著降低。实验结果表明:含铜量为1.14%的合金具有较好的机械性能和抗腐蚀能力。     

An Overview of High-Performance Aircraft Structural Al Alloy-AA7085

AA7085 Al alloy is a new-generation,high-strength,quench-insensitive alloy that features in airframe applications such as massive bulkhead and wing spars structures in Airbus A380 and Joint Strike Fighter aircrafts.This alloy has a great potential in replacing currently used high-strength AA7 xxx alloys in many international and national military aircraft programs [Hawk,Su-30,Mi G series,light combat aircraft(Tejas),Hindustan turbo/jet trainer,light combat helicopter,advanced light helicopter,and fifth-generation fighter aircrafts].An effort has been made to highlight the processing,heat treatment,properties and applications of the AA7085 Al alloy from the existing literature on the AA7085 alloy.The potential applications of this alloy are presented and compared with the currently used AA7075 Al alloy.A typical process cycle involved in the manufacturing of wrought AA7085 alloy products is described in detail.Particularly,the precipitation mechanisms involved in the different temper conditions are critically reviewed with the supporting microstructures.The mechanical properties with a particular emphasis on tensile,fatigue,and fracture toughness properties are discussed in detail based on the analysis of experimental data.The effects of temper conditions on the stress corrosion cracking and exfoliation corrosion have also been reviewed critically.     

Corrosion resistance of aluminum-lithium alloys under various climatic conditions

The corrosion resistance (stress corrosion cracking, exfoliation, intergranular corrosion) of a wide group of aluminum-lithium alloys has been studied under atmospheric conditions with various corrosion environments. Corrosion behavior of experimental and commercial batches of aluminum-lithium alloys has been established as a function of the chemical composition of the alloys and ratio of Cu/Mg, Li/Cu + Mg. Under atmospheric conditions, the best corrosion properties are those of an alloy with a Cu/Mg ratio of 0.5 and a ration of Li/Cu + Mg of 0.96. It has been proved that a decrease in Li/Cu + Mg to 0.56–0.76 leads to impairment of corrosion properties. Accelerated corrosion tests result in the same conclusions.     

Zn含量对铸态Mg-2Er合金的微观结构及力学性能影响

采用XRD和SEM等微观表征技术研究不同Zn添加量对Mg-2Er合金微观组织和力学性能的影响。结果表明：当Zn添加量为1%和2%时,合金主要相组成为W相和α-Mg;当Zn添加量为4%-10%时,合金中则有I相析出,合金相成分变为W相、I相和α-Mg;当Zn添加量增加至12%时,W相消失,合金中主要第二相则为I相和Mg4Zn7相。当Zn添加量为6%时,合金具有较好的拉伸力学性能,其抗拉强度、屈服强度和伸长率分别为224 MPa、134 MPa和10.4%。     

Microstructure,mechanical properties,and corrosion resistance of Mg–9Li–3Al–1.6Y alloy

Mg–9Li–3Al–1.6Y alloys were prepared through mixture method. The microstructure, mechanical properties, and corrosion resistance of the as-cast and asextruded alloys were studied by optical microscopy(OM),scanning electronic microscopy(SEM), X-ray diffraction(XRD), mechanical properties testing, and electrochemical measurement. The as-cast Mg–9Li–3Al–1.6Y alloy with the average grain size of 325 lm is composed of b-Li matrix, block a-Mg, and granule Al_2Y phases. After extrusion, the grain size of the as-cast alloy is obviously refined and reaches to 75 lm; the strength and elongation of the extruded alloy are enhanced by 17.20 % and49.45 %, respectively, owing to their fine microstructure and reduction of casting defects. The as-extruded alloy shows better corrosion resistance compared to the as-cast one, which may be related to the low stored energy and dislocation density in the extruded alloy, also the homogenization treatment before extrusion.     

添加合金元素对改善快速凝固铝锂合金性能的作用

通过研制Al 2 .5Li,Al 2 5Li 0 2Zr,Al 2 5Li 1 2Mg 0 2Zr,Al 2 5Li 1 6Cu 1 2Mg 0 2Zr4种成分的快速凝固铝锂合金 ,研究了逐步添加合金元素Zr,Mg ,Cu对合金力学性能的影响。结果表明 :在快速凝固铝锂合金中逐步加入少量合金元素Zr,Mg ,Cu后 ,合金强度逐步增加 ,而延伸率无明显变化 ,这有助于强化合金基体和阻碍合金基体的剪切型断裂 ,有助于改善合金的综合力学性能 ,其中Al 2 5Li 1 6Cu 1 2Mg 0 2Zr合金综合力学性能最优 ,其密度、强度、塑性等都全面达到了国家高技术项目的技术指标。     

The influence of copper content on intergranular corrosion of model AlMgSi(Cu) alloys

Application prospects in automotive and aerospace industry have led to extensive studies on AA6xxx alloys in recent years. Varying amounts of Mg, Si and Cu and heat treatments are used to achieve the desired mechanical properties in these alloys. In this investigation, a series of tests have been designed and carried out on model AlMgSi(Cu) alloys to investigate the effects of Cu, Mg and Si composition and heat treatments on the corrosion properties for a range of Cu content levels (0.03, 0.15 and 0.80 wt%, respectively). The results indicate that the localized corrosion susceptibility of the model alloys primarily increased with Cu content. The Si and Mg content and ratio do not appear to have a significant effect on the local corrosion behaviour. Heat treatment can improve the corrosion resistance. However, this effect is small compared to that of the Cu content for the range of model alloys investigated. Intergranular corrosion will occur by micro‐galvanic coupling between the cathodic AlMgSi(Cu) (Q) phase precipitates and the aluminum matrix adjacent to the particles. The increasing susceptibility to intergranular corrosion with Cu content can be attributed to an increased formation of Q phase particles.     

添加Sc和提高Zn含量对7085铝合金力学性能、淬火敏感性和耐蚀性能的影响

在7085铝合金基础上添加Sc和提高Zn含量制备了3种不同成分的热轧薄板样品,在470℃加热1 h后分别风冷(FC)和水冷(WC)淬火,然后进行120℃×24 h人工时效。再采用室温拉伸和晶间腐蚀试验及光学显微镜和透射电镜观察等试验方法,研究Sc和Zn对7085铝合金力学性能和耐蚀性能的影响。结果表明,添加Sc可以显著细化晶粒、钉扎位错、抑制再结晶、提高形核率、降低晶界无沉淀析出带的宽度及晶界析出相尺寸,从而有利于提高合金的强度与耐蚀性能,淬火敏感性也有所提高。在含Sc的基础上进一步提高Zn含量会使淬火诱导相的析出驱动力增大,晶内析出相和晶界析出相的数量增加,时效后合金的强度进一步提高,淬火敏感性显著增强,耐蚀性能有所下降。