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采用固液混合铸造技术制备了Al-10Mn合金坯料,将坯料进行热挤压加工,研究了加热温度对挤压加工的影响及传统铸造、固液混合铸造以及固液混合铸造坯料的热挤压加工制备的Al-10Mn合金的显微组织和力学性能。结果表明:固液混合铸造合金的析出相细小、均匀、圆整,抗拉强度提高到130 MPa,热挤压后合金的抗拉强度增加到181 MPa;当坯料加热温度为600℃时,挤压加工的合金具有最好的力学性能和较为均匀的显微组织;当坯料加热温度为570℃时,坯料则不能顺利挤出;而当坯料加热温度高于610℃时,合金力学性能大幅降低。 相似文献
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采用固液混合铸造研究了Al-10Mn、Al-15Mn和Al-20Mn合金的显微组织和力学性能.研究表明:固液混合铸造能有效地细化Al-Mn合金组织,其初生相尺寸可控制在10 μm以内,且形貌以球形或等轴状为主;合金的抗拉强度大大提高,由传统铸造的40~60 MPa提高到110~160 MPa,伸长率由零提高到1%左右;传统铸造和固液混合铸造的Al-Mn高合金的组织随着Mn含量的增加而更加粗大,抗拉强度则下降,硬度有所提高.采用固液混合铸造这一新型的材料制备技术,可以扩展Al-Mn等高合金材料的研究和应用的成分范围. 相似文献
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《铸造》2015,(12)
研究了固溶处理温度和固溶处理时间对挤压铸造Al17.5Si4Cu0.5Mg0.1Mn合金显微组织及硬度的影响。结果表明:固溶处理后合金的显微组织得到明显改善,硬度大幅度提高。随着固溶温度的增加,共晶Si相逐渐粒化,合金的布氏硬度值逐渐增加,当固溶温度为525℃时,共晶Si相形貌相对圆整,合金具有最大布氏硬度值;随着固溶时间的延长,合金显微组织中的共晶Si相发生熔断、粒化、粗化现象,合金的布氏硬度呈现先上升后下降的趋势,当固溶时间为6 h时,合金的布氏硬度达到最大值HB 124。试验得到的挤压铸造Al17.5Si4Cu0.5Mg0.1Mn合金的最佳固溶处理工艺为525℃,保温时间为6 h。 相似文献
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在固液混合铸造工艺中,将Al-20Cu合金粉末分别加入到Al-20Cu和Al-40Cu合金熔体中制备了合金坯料。采用JSM-6700F扫描电子显微镜对合金坯料的显微组织进行观测。研究结果表明:Al-20Cu粉末加入对粉末周围的Al-20Cu合金基体初生相、共晶组织和二次析出相有明显的细化作用,越靠近未熔粉末,基体中的初生相越细小,共晶组织的片间距越小。固液混合铸造Al-40Cu合金坯料中未熔Al-20Cu合金粉末与基体界面结合良好,表明固液混合铸造工艺中加入的金属粉末的成分范围可以进行扩展。 相似文献
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《热加工工艺》2015,(16)
研究了不同含量的Mn和Re对AZ102镁合金组织性能的影响。结果发现,加入Mn后合金中的β相被细化成颗粒状弥散分布于基体内,还出现了颗粒状的Al-Mn化合物,随Mn含量的增加,Al-Mn相尺寸变大。在含Mn的镁合金基础上加入稀土后,晶粒尺寸明显细化,β相变得更加弥散,同时加入的Re会和Al形成Al4Re相并随Re含量的增加,Al4Re相会由颗粒状变为短杆状再变为针状,并且Al-Mn颗粒相也会受到Re含量的影响使得合金中形成大颗粒的Al-Mn化合物。添加0.2%Mn和0.5%Re时,组织中的一部分颗粒状Al4Re相转变为短杆状,Al-Mn相也较细小,该合金的综合性能最好,抗拉强度249.6 MPa、伸长率5.65%和硬度71 HB相比1#合金分别提高了24.3%、232.4%和6.3%。 相似文献
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Al5TiB对Mg-8Zn-4Al-0.3Mn合金时效过程的影响 总被引:2,自引:1,他引:2
研究了Al5TiB加入量对Mg-8Zn-4Al-0.3Mn铸造镁合金时效过程的影响. 结果表明, 未加Al5TiB的Mg-8Zn-4Al-0.3Mn合金的时效析出过程为 过饱和固溶体→细小弥散析出相→再结晶软化和析出相的聚集长大; 添加Al5TiB的Mg-8Zn-4Al-0.3Mn合金的时效析出过程为 过饱和固溶体→细小弥散析出相→析出相的聚集长大. 固溶处理后, 与未加Al5TiB的合金1#相比, 合金2#、3#、4#显微硬度值分别提高了2.8%、6.8%、9.1%; 人工时效后, 与未加Al5TiB的合金1#相比, 合金2#、3#、4#显微硬度峰值分别提高了9%、11.2%、5.2%. 随着Ti元素在合金中含量的增加, 合金的析出相形成激活能呈先增大而后减小的变化规律. 相似文献
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A two-step reheating process was proposed and applied to perform reheating experiments on the semi-solid 2024 alloy billet. In this process, the semi-solid billet was firstly heated over liquidus temperature and then isothermally held at solid-liquid zone temperature. Microstructure evolution of the semi-solid billet during two-step reheating was studied by optical microscope and compared with that during isothermal reheating. The results show that the remelting rate of the semi-solid billet during two-step reheating is faster than that during isothermal reheating. Under the same reheating time, the grains of the semi-solid billet reheated by two-step reheating process are finer and rounder than those by isothermal reheating process. The present experimental results indicate that accelerating the formation of liquid phase during the two-step reheating process can restrain the coalescence of grains to a certain extent, and thus refine the grain size and promote the grain spheroidization. 相似文献
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6061铝合金半固态坯料二次加热工艺及组织演变 总被引:3,自引:3,他引:0
针对近液相线半连续铸造技术制备的6061铝合金半固态坯料,在不同加热温度及保温时间下进行二次加热,采用光学显微镜及图像分析仪考察试样的微观形貌及尺寸特征,结合差热分析的方法研究加热过程中的液相形成、组织演变及晶粒长大过程。结果表明,二次加热温度及保温时间共同影响着微观组织演变过程,随着加热温度升高及保温时间延长,晶粒逐渐球化并长大。加热温度越高,组织演变速度越快;保温时间越长,晶粒球化并长大越明显。有效地控制二次加热温度及保温时间,能够获得均匀、圆整且相对细小的半固态组织。 相似文献
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Liu XiancuiPan YeTang ZhijiaoHe WeiqiaoLu Tao 《金属学报》2017,(11):1487-1494
The process of production and working environment of heat exchangers call for materials with good elevated temperature properties. However, the previous investigations were mainly focused on their room temperature properties. The relationship between microalloying and high temperature properties, especially creep properties of Al-Mn-based alloys are barely discussed. In order to improve the industrial applications of Al-Mn-based alloys, the effect of Mg, Ni and Zr additions and annealing process on the microstructure and high temperature properties of Al-Mn-based alloys were studied in this work. The investigated alloys were treated in two ways, first one is cold-rolling and heat treatment at 873 K for 10 min, and the second one is cold-rolling, heat treatment at 623 K for 1 h and 873 K for 10 min. The results indicate that annealing process has remarkable effect on the grain shape, fine equiaxed crystal grains are obtained in the former, while stable elongated grains are obtained for precipitation precedes recrystallization at 623 K in the latter. With Mg addition, more AlMnSi phase precipitated during annealing. The addition of Zr and Ni increases the type and amount of heat resistant compounds, precipitate Al3Zr and AlMnSiNi, which are beneficial to improving high temperature properties of Al-Mn alloy. Al-Mn-0.3Mg-0.2Ni alloy has the best elevated temperature properties, and the tensile strength of it is 102 MPa (50 MPa higher than Al-Mn alloy) at 523 K. And the steady-creep rate is strongly decreased to 3.93x10(-8) s(-1), two orders of magnitude smaller than Al-Mn alloy at the temperature of 523 K under the stress of 40 MPa. With dispersoids complicated or increased, the movement of dislocations are pinned strongly, which are contribute to improving the creep properties of Al-Mn alloy for the creep is mainly controlled by dislocation climb. 相似文献
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采用触变挤压工艺成形ZCuSn10P1铜合金轴套零件,通过单向拉伸实验和硬度实验研究了触变挤压铜合金的抗拉强度、延伸率、布氏硬度和显微硬度,利用扫描电镜观测了断口形貌并分析了断裂方式,分析了成形比压对触变挤压铜合金力学性能的影响规律。结果表明,抗拉强度随成形比压增加而先增加后降低。延伸率随成形比压增加而不断减小。成形比压与抗拉强度和延伸率的函数关系分别为抛物线和幂指数。触变挤压铜合金拉伸断裂方式为沿晶断裂和韧性断裂的混合型断裂。布氏硬度随成形比压增加而先增加后降低。相同工艺条件时,液相显微硬度值最高,固液界面次之,固相最低。固相、固液界面和液相的显微硬度均随成形比压增加而先增加后降低。触变挤压铜合金综合力学性能要高于常规铸造,较佳工艺参数为成形比压250 MPa、挤压速率15 mm/s,其抗拉强度、延伸率和布氏硬度分别为387 MPa、2.8%、128 HBW。 相似文献
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Ridvan GECU Serhat ACAR Alptekin KISASOZ Kerem ALTUG GULER Ahmet KARAASLAN 《中国有色金属学会会刊》2018,28(3):385-392
The effects of T6 heat treatment on thixoforged A356 and A380 aluminium alloys were studied. Low superheat casting (LSC) technique was carried out to prepare proper specimens for thixoforging process. The samples were poured at 20 °C above their liquidus temperatures which provided the formation of equiaxed grains instead of dendritic growth. Produced billets were reheated for varied time from 20 to 80 min and thixoforged with 50% deformation rate. After thixoforging process, the samples were T6 heat treated for both A356 and A380 alloys. The microstructural evaluation and hardness alteration of thixoforged, solution treated and aged specimens were examined comparatively by using optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy and Brinell hardness equipment. T6 heat treatment provided relatively uniform microstructure with newly formed precipitates that are Mg2Si and Al2Cu for A356 and A380 billets, respectively. Accordingly, hardness after artificial aging was increased considerably and reached HB 93 for A356 and HB 120 for A380 alloys. 相似文献
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试验研究磁性相互作用对Bi-Mn合金中MnBi析出相磁致织构组织稳定性的影响,结果发现取向析出相晶粒间磁性相互作用不仅能够使织构组织在无磁场降温过程中稳定存在,而且能够使之在无磁场条件下重新加热至低于MnBi化合物Curie温度(居里温度,指磁性相变发生的温度)的固液两相区凝固过程中稳定存在.从磁性物理出发分析取向晶粒间磁性相互作用的特点,较好地解释了试验现象. 相似文献