Al-4.0Cu合金时效初期原子分布的计算机模拟

为了准确描述Al-4.0Cu合金时效初期Cu原子团簇的分布状态,采用了Monte Carlo方法建立模型,模拟了Al-4.0Cu合金时效初期Cu原子团簇的演变过程,得到了原子状态分布图.结果表明：Al-4.0Cu合金时效处理时,Cu原子有强烈丛聚的倾向;时效初期十几秒时,在原子面上出现了较大的Cu原子簇;合金元素原子依靠空位扩散迁移,Cu原子的偏聚程度随空位浓度的增加而加剧.     

含微量Sc和Zr的Al—Cu—Mg—Fe—Ni合金时效行为和拉伸性能

配制了３种不同成分的Ａｌ－Ｃｕ－Ｍｇ－Ｆｅ－Ｎｉ系实验合金,研究了微量Ｓｃ和Ｚｒ对该系合金时效行为和拉伸性能的影响。用硬度法测量了合金在２００℃和３００℃下的时效硬化曲线,用航向电镜观察了合金在淬火及２００℃时效不同时间后的显微组织。在室温（２０℃）,２００,２５０,３００℃征测量了合金的拉伸力学性能,用扫描电镜观察了拉伸断口形貌。结果表明：加入微量Ｓｃ,Ｚｒ后生成的Ａｌ３（Ｓｃ,Ｚｒ）质点均匀弥     

6061合金吊钩时效强化工艺研究

研究了实际生产中的时效热处理工艺对6061合金吊钩强度的影响,对产品采用机械加工后直接人工时效及先固溶再时效的两类时效工艺;测定了强度及硬度值;用光学显微镜和透射电子显微镜进行了显微组织观察;比较了不同时效工艺的试样在性能和组织方面的变化;提出了相对较为经济有效的时效强化工艺．     

Al-6Zn-2Mg-2Cu合金热处理后的拉伸与晶间腐蚀性能

为了研究不同时效处理对Al-6Zn-2Mg-2Cu合金性能的影响,研究了强化固溶后T6和T76时效处理对Al-6Zn-2M g-2Cu合金硬度、拉伸性能与晶间腐蚀性能的影响.结果表明,强化固溶后与经过T6时效处理的合金相比,T76时效处理后合金的硬度并无明显变化,但合金的抗拉强度下降了4.39%,伸长率则明显上升.经T6和T76时效处理后,合金的晶间腐蚀等级均为4级.两种时效状态下合金腐蚀速率均在0~1.5 h范围内急剧增大,之后开始下降.经过强化固溶与T76时效处理后,合金的抗晶间腐蚀性能得到明显改善.     

Zn在AlSiCuMg合金时效过程中的作用

研究了微量合金元素Zn对高强度铸造合金Al-Si-Cu-Mg时效过程的影响.通过差热分析和透射电镜等分析测试方法表明：当锌的添加量在w(Zn)=0.1%～1.0%时，可提高合金的时效峰硬度，加快合金的硬化速度.当Zn含量为0.5%时，合金的时效峰最高，当Zn含量增大到w(Zn)=1%时，硬度有所降低，但仍高于无Zn合金.通过DSC和TEM分析显示，微量的Zn固溶于基体中，加快了亚稳相的析出，较早地形成了细小而密集的亚稳相，从而使合金获得了较高的峰时效硬度.     

T4态Al-Mg-Si合金板材的预时效工艺研究

采用硬度和电导率测定结合TEM/EDS组织分析研究了预时效温度及预时效时间对T4态Al-1.3Si-1.2Mg-0.6Cu合金板材成形性能、室温停放稳定性及烤漆硬化性的影响.结果表明：能同时有效改善该合金T4态板材的成形性、室温停放过程中的组织性能稳定性及烤漆硬化性的最佳预时效工艺为190℃左右保温约8 min.当预时效温度高于190℃或预时效时间过长,将不利于合金板材成形性的改善;若预时效温度低于190℃或预时效时间过短,则不利于合金板材预时效处理后的室温停放稳定性及烤漆硬化性的发挥.     

时效对Cu—Cr—Zr合金显微硬度及导电率的影响

探讨了时效工艺及形变量对Cu—0.3Cr—0．15Zr合金显微硬度及导电率的影响。结果表明，合金经920℃固溶处理后在420℃及460℃时效可分别达到较好的硬度和导电率，分别达183HV和68％IACS；时效前对合金加以适当冷变形可加速合金时效析出过程。影响合金导电率的主要因素是基体中固溶元素的含量，含量越高，导电率越低，反之则越高。而时效前冷变形可以增加合金内部位错等缺陷的数量，加速了合金第二相的析出。     

微量Ag对Al2014合金微观组织和拉伸性能的影响

通过拉伸测试和透射电子显微分析等手段,研究了微量Ag对Al2014合金微观组织和拉伸性能的影响.结果表明:微量Ag元素的加入明显提高了Al2014合金的拉伸性能.Ag的添加改变了铝合金的时效行为,在铝基体{111}面上析出了一种新的六边形片状Ω(Al2Cu)相.合金强度的提高归因于Ω(Al2Cu)相的沉淀硬化作用.     

GH8607双相铁基合金的时效行为

目的 对ＧＨ８６０７双相铁基合金的时效过程,强化相析出和基体相变进行研究,方法 采用高温Ｘ射线衍射,热膨胀分析,ＴＥＭ等试验手段,结果 ＧＨ８６０７合金时效时具有较高的硬化速率,析出相为碳化物（Ｍ２３Ｃ６,Ｍ６Ｃ）和金属间化合物（Ｌａｖｅｓ相,Ｘ相）时效过程中的出现δ→γ转为,并在随后的冷却中产生板条马氏体,时效后经多次重复加热,在马氏体中沉淀出强化相,结论 ＧＨ８６０７合金具有高的时效温度和热强     

Thermodynamic analysis of the formation of <Emphasis Type="Italic">In-situ</Emphasis> reinforced phases in cast Al-4.5Cu alloy

The thermodynamic analysis of the formation of in-situ reinforced phases in （TiB2＋Al3Ti）/Al-4.5Cu composites prepared by mixed salts reaction was conducted, and heat changes of mixed salts system were analyzed by differential thermal analysis（DTA）.The results show that although TiB2 possesses the strongest formation ability in Al-Ti-B ternary system, [Ti] is relatively excessive in the in-situ reaction and it combines with Al to form AlaTi phase. The reinforced phases are TiB2 and AlaTi in the produced composites due to the reaction taking place to form reinforced phase with the addition of mixed salts into Al-4.5Cu melt between 900 ℃ and 1 032 ℃.     

Effect of homogenization treatment on microstrucmre and properties of Al-Mg-Mn-Sc-Zr alloy

The effect of homogenization on the hardness, tensile properties, electrical conductivity and microstructure of as-cast Al-6Mg-0.4Mn-0.25Sc-0.12Zr alloy was studied. The results show that during homogenization as-cast studied alloy has obviously hardening effect that is similar to aging hardening behavior in traditional Al alloys. The precipitates are mainly Al3（Sc,Zr） and Al6Mn When homogenization temperature increases the hardness peak value is declined and the time corresponding to hardness peak value is shortened. The electrical conductivity of the alloy monotonously increases with increasing homogenization temperature and time. The decomposition of the supersaturated solid solution containing Sc and Zr which is formed during direct chilling casting and the precipitation of Al3（Sc, Zr） cause hardness increasing. The depletion of the matrix solid solubility decreases the ability of electron scattering in the alloy, resulting in the electrical conductivity increased. Tensile property result at hot rolling state shows that the optimal homogenization treatment processing is holding at 300-350℃ for 6-8 h.     

Al_2O_3/Al合金复合材料的耐磨性的研究

以国产氧化铝短纤维作为增强体,制备了氧化铝短纤维增强铝合金复合材料。本文研究了这种材料的耐磨性能,研究结果表明,氧化铝短纤维具有增强作用,复合材料比基体有高得多的硬度;在润滑条件下,复合材料的磨损率比基体的低,在较大载荷作用下,复合材料表现了优良的抗粘着磨损的能力,在一般磨损情况下,纤维体积率小于15％,可保证复合材料有足够的耐磨性。     

干摩擦条件下Al_2O_（3f）／ZL109复合材料的磨损行为

用压铸法制备Ａｌ２Ｏ（３ｆ）／ＺＬ１０９复合材料，研究了恢复合材料在干摩擦条件下磨损量与滑动距离的关系，结果表明：复合材料磨损失效的临界值远高于其基体合金．同一时刻对应的耐磨性也明显高于基体合金。借助ＳＥＭ及ＥＰＭＡ等手段对磨损表面及亚表面和粘着磨损的材料转移情况进行了观察和分析，并对磨损机制进行了讨论。     

The aging feature of Al-Li-Cu-Mg-Zr alloy containing Sc

The aging behaviors of Al-1.42% Li-2.41% Cu-0.93% Mg-0.073% Zr-0.17% Sc (mass fraction, the same below) alloy at room temperature, 160 °C, and 160°C after 8% pre-deformation were studied respectively by hardness measurement. The microstructure of the alloy in various aging conditions was observed by TEM. The results show that the main precipitations of the alloy in quenching condition are the particles containing Sc and Zr which have certain coherent relation with the matrix. Addition of Sc in Al-Li-Cu-Mg-Zr alloy will be favorable to promoting precipitation. The particles can serve as preferred nucleation sites for δ′ phases which accelerate the aging hardening rate at initial aging. The main hardening phases of the alloy aged at 160 °C are δ′ and δ′/β′ composite precipitates. The size of the composite precipitates is very small (nanometer size). The composite precipitates will preclude efficiently the formation concentrative slip location and will improve the mechanical properties of the alloy. S′ phase will occur in the alloy aged at 160 °C after 8% pre-deformation. It is found that 8% pre-deformation has no obvious influence on the precipitation of the composite phase. Foundation item: The Key Program of the 9th Five-year Plan of China (No. 95-YS-001) Biography of the first author: TAN Cheng-yu, associate professor, born in 1963, majoring in materials and their suface performances.     

Effect of Cold-rolling on Hardness of SiC_w/Al Composite

1　IntroductionDiscontinuouslyreinforcedaluminummetalmatrixcomposites (AMCs)arenowrecognizedasimportantstructuralmaterials[1,2 ] .Oneoftheprimeadvantagesofthesematerialsisthattheycanbeprocessedandshapedbyconventionalmetalworkingtechniques ,suchasextru sio…     

激光熔覆钛基复合涂层的显微组织和硬度分析

采用激光熔覆快速非平衡合成方法制备了原位反应合成TiB增强钛基复合材料.用Y2O3、Ti和B的混合粉末在Ti-6Al-4V基体表面激光熔覆制得TiB/Ti复合涂层.采用X线衍射仪(XRD)、扫描电子显微镜(SEM)、能量散射光谱仪(EDS)和硬度测试等方法,研究了原位合成TiB/Ti复合涂层的显微结构和显微硬度.结果显示:激光熔覆层的相结构主要为α-Ti和TiB两相,TiB增强相均匀地分布于复合涂层中,熔覆层的硬度值高于基体Ti合金的硬度值1倍以上,Y2O3含量(质量分数w,全文同)为1％的激光熔覆涂层内部的增强相组织最为均匀、细小,且硬度值也最高,平均硬度(HV)值约为830.     

Instability of TiC and TiAl3 compounds in Al-10Mg and Al-5Cu alloys by addition of Al-Ti-C master alloy

The performance of Al-Ti-C master alloy in refining Al-10Mg and Al-5Cu alloys was studied by using electron probe micro-analyzer （EPMA） and X-ray diffractometer （XRD） analysis. The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds. Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading. However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti（Al, Cu）2, which is responsible for the refinement fading in Al-5Cu alloy. These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.     

一种高硬度铸造镁合金

设计了一种成分（质量分数/%）为Mg-8Zn-6Al-3Cu-3Ca-1.5Mn-1Si的合金,利用金相显微镜、扫描电镜、X射线衍射和维氏硬度计研究了自然冷却、快速冷却及时效处理对合金显微组织和硬度的影响.Mg-8Zn-6Al-3Cu-3Ca-1.5Mn-1Si合金慢冷组织主要由α-Mg、Mg2Cu6Al5、CaMgSi、Mg2Zn3等相构成,没有出现Mg17Al12相.合金经快冷后,抑制了第二相从基体中的析出;时效10 h后,CaMgSi相以细小的块状相均匀析出.合金具有较高的硬度值,在时效时间10 h时最大HV值达到111.     

氧化铝短纤维增强铝基复合材料的性能研究

利用国内现有的原料制备出了氧化铝短纤维增强铝基复合材料。研究了强度、硬度及耐磨性能与纤维体积率、基体合金的关系并对复合材料的拉伸断口做了扫描观察。实验表明:在相同的工艺条件下,氧化铝短纤维与基体合金复合良好;氧化铝短纤维增强铝基复合材料的强度、硬度及耐磨性能均随纤维体积率的增加而提高;在基体中加入适当的合金元素还可进一步提高复合材料的性能。