7075铝合金2540mm×550mm规格扁锭铸造工艺研究

试验研究了大规格7075铝合金扁锭的铸造工艺。结果表明:通过控制Fe、Si元素的含量可以改善铸造裂纹;采用软起铸,当铸造速度为40 mm/min～50 mm/min、铸造温度为675℃～685℃、冷却水温度为35℃～40℃、冷却水流量为40 m~3/h～70 m~3/h、结晶器液位高度60 mm～100 mm的条件下,铸造出表面无皱褶、裂纹、锭尾塌陷和成分均匀、晶粒细小的7075铝合金扁锭。解决了用2 540 mm×550 mm规格的7075铝合金扁锭生产航空货运用成品宽度超过2 300 mm的宽幅铝板必须横轧的问题,提高了成品率的同时降低了生产成本。     

电磁软接触铸造7050高强铝合金扁锭的组织和力学性能

通过数值模拟与试验研究的方法,采用软接触电磁铸造技术制备7050高强铝合金扁铸锭。模拟结果表明,施加软接触电磁场后,铸锭内部的流动场和温度场分布均发生改变。试验结果表明:采用电磁软接触铸造技术后,铸锭表面粗糙度由常规铸造时的101.1μm降低至48.6μm,平均晶粒由常规铸造时的80～85μm细化至55～70μm,晶粒尺寸不均匀度由常规铸造的21.69%降低至11.50%;此外,采用电磁软接触铸造工艺后,铸锭的合金化元素偏析得到抑制,Zn、Mg、Cu三元素的最大偏析率分别由常规铸造时的6.62%、9.54%、7.92%降低至3.87%、3.63%、1.36%,合金化元素分布更加均匀。     

7055铝合金扁锭铸造工艺研究

利用Almex铸造机,试验研究7055铝合金扁锭的铸造工艺,并对铸锭的化学成分和显微组织进行了分析。试验结果表明:采用高效铝熔体洁净技术,保证了熔体质量;采用软起铸的铸造工艺,可促进铸锭成形,降低开裂倾向;通过多级可控温铝制结晶器进行铸造,浇注温度在700～710℃,结晶器水流量控制为15 m3/h～60 m3/h,铸造速度为30 mm/min～50 mm/min,结晶器液位高度为70 mm～105 mm,获得了外观质量良好、内部成分均匀、高倍组织细小的7055铝合金扁锭。     

操纵壳体压铸充型和凝固过程的数值模拟

基于正交试验方法,并结合MAGMA铸造模拟软件对铝合金操纵壳体压铸工艺参数进行优化模拟研究,确定了指导压铸生产的优化工艺参数:压射速度为3.0 m/s,速度转换位移500 mm,模具温度为180℃。通过企业生产试验,验证了模拟所确定优化工艺参数的合理性,证明了压铸过程数值模拟的可靠性。     

2024铝合金2700mm×550mm扁锭铸造工艺研究

采用Almex铸造机,试验研究大规格2024铝合金扁锭的铸造工艺。结果表明:通过控制Fe元素和Be元素的含量可以改善铸锭的表面质量,提高铸造成功率;在铸造温度680℃～690℃、铸造速度25 mm/min～45 mm/min、水流量控制在20 m3/h～80 m3/h、结晶器中的铝液位高度60 mm的工艺参数下,可以铸造出规格为2 700 mm×550 mm的2024铝合金扁锭,提高了铸锭的成品率,降低生产成本。铸造出的扁锭表面无皱褶、裂纹、锭尾塌陷等缺陷,铸锭组织、成分均匀,晶粒度细小,满足用户需求。     

某大型复杂圆筒类低压铸造工艺改进

针对大型航空铝合金铸件的结构特点和性能要求,在分析采用砂型重力铸造该类铸件时各种铸造缺陷产生原因的基础上,研究采用低压铸造工艺的可行性,利用低压铸造工艺的原理和优点,结合铸造模拟软件解决大型航空铝合金铸件的成型质量问题,通过铸件结构分析及其铸造原理分析,进行低压铸造铸型的设计,利用铸造模拟软件并结合工艺试验,确定铸件低压铸造生产工艺参数,解决了铝合金铸件在铸造过程中的气孔、缩松、夹渣等缺陷问题。     

新型超高强铝合金扁铸锭熔铸工艺研究

Zn的质量分数超过7.5%的新型超高强合金是重要的航空结构材料,该合金铸造时有很强的热裂纹倾向性,其熔炼铸造工艺是研究的重点.对新型超高强合金的熔炼与半连续铸造工艺开展系统研究,考察了合金成分、精炼条件、铸造温度、铸造速度等工艺参数对铸锭成形性的影响,最终确定了合理的熔铸工艺,成功地制备出优质的200 mm×600 mm规格扁铸锭.     

Cu、Mg、Zn对铸造铝合金YL102电导率的影响

研究了Cu、Mg、Zn对铸造铝合金YL102电导率的影响.结果表明Cu、Mg、Zn的存在都使得铸造铝合金YL102的电导率下降.要保证电导率γ＞17 S/m,应严格控制铸造铝合金YL102中的Cu、Mg、Zn含量,Cu的质量分数不高于1.7%, Mg的质量分数不高于0.3%,Zn的质量分数不高于1.1%.     

复杂铝合金铸件铸造工艺优化与设计

针对大型航空薄壁铝合金铸件的结构特点和性能要求,利用低压铸造工艺的原理和优点,结合铸造模拟软件解决大型航空铝合金铸件的成型问题。通过铸件结构及铸造原理分析,进行低压铸造铸型的设计。结果表明,利用铸造模拟软件,结合工艺试验对铸型设计、浇注工艺进行了验证,确定了铸件的低压铸造产生工艺和过程参数,解决了大型航空铝合金铸件的气孔、缩松、裂纹等缺陷问题。     

ZK61M变形镁合金铸造工艺研究

ZK61M变形镁合金铸造过程中经常出现铸锭表面开裂。据此试验研究了合金成分(Zn、Zr含量)对铸锭组织和性能的影响,铸造工艺参数(铸造温度、冷却强度、铸造速度、结晶器)对铸锭质量和开裂缺陷的影响,铸锭均匀化工艺参数对铸锭组织和加工塑性的影响。确定了ZK61M镁合金的成分范围,w(Zn)=5.3%~5.5%,w(Zr)=0.6%~0.8%;优化了铸造工艺参数,防止熔体过热,铸造温度695℃~705℃,铸造速度36 mm/min~40 mm/min,改进结晶器,减少二次水冷却强度;铸锭均匀化工艺参数390℃12 h。这样形成了ZK61M镁合金铸锭稳定的生产工艺,大大减少了铸锭表面开裂。     

新型Al-Mg-Cu铝合金铸锭均匀化过程中相的变化

采用金相、扫描电镜、能谱和DSC分析方法研究了新型Al-Mg-Cu铝合金(以下简称A铝合金)半连续水冷铸锭均匀化处理过程中相的变化.结果表明,A铝合金半连续铸锭的铸态组织中存在大量非平衡凝固的含Al2CuMg和Al2Cu的共晶相,其熔化温度为505℃;在595℃12 h均匀化过程中,该合金铸锭中非平衡凝固共晶相发生溶解,合金中铸造过程形成的非平衡凝固共晶体Al2Cu全部消失,但Al2CuMg相不能完全溶解.     

Microstructural evolution of high strength 7B04 ingot during homogenization treatment

The evolution of the microstructure and phases of the direct chill semicontinuous casting ingot of 7B04 super-high strength aluminum alloy during homogenization treatment was studied with metallographic analysis, scanning electron microscopy（SEM）, energy spectroscopy and differential scanning calorimetry（DSC）. The results show that a considerable amount of non-equilibrium eutectics containing AI, Zn, Cu and Mg exist in the direct chill semicontinuous casting ingot of 7B04 super-high strength aluminum alloy, and their melting point is 478℃. During homogenization treatment at 470℃, these eutectics dissolve into the matrix partly, coarsen and also transform into Al2CuMg phase whose equilibrium melting point is 490℃ in the alloy. Moreover, the homogenization treatment at 470℃ for 72 h results in the disappearance of the non-equilibrium eutectics though Al2CuMg phase can not dissolve completely.     

Effect of electromagnetic field on macrosegregation of continuous casting 7075 alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭａｃｒｏｓｅｇｒｅｇａｔｉｏｎｉｓｏｎｅｏｆｔｈｅｍｏｓｔｐｒｏｎｏｕｎｃｅｄｄｅ ｆｅｃｔｓｄｕｒｉｎｇｃｏｎｔｉｎｕｏｕｓｃａｓｔｉｎｇｏｆａｌｕｍｉｎｕｍａｌｌｏｙｓ ,ｗｈｉｃｈｌｅａｄｓｔｏｌａｒｇｅ ｓｃａｌｅｉｎｈｏｍｏｇｅｎｅｉｔｙｏｆａｌｌｏｙｉｎｇｅｌｅｍｅｎｔｓ .ＡｓａｔｙｐｉｃａｌＡｌ Ｚｎ Ｍｇ Ｃｕａｌｌｏｙ ,70 75ａｌｌｏｙ ｓａｓ ｃａｓｔｓｔｒｕｃｔｕｒｅｓｐｒｅｓｅｎｔｓｅｖｅｒｅｉｎｖｅｒｓｅｓｅｇｒｅｇａｔｉｏｎ .Ａｌｌｏｙｉｎｇｅｌ ｅ…     

Overheating temperature of 7B04 high strength aluminum alloy

The microstructure and overheating characteristics of the direct chill semicontinuous casting ingot of 7B04 high strength aluminum alloy, and those after industrial homogenization treatment and multi-stage homogenization treatments, were studied by differential scanning calorimetry(DSC), optical microscopy(OM) and scanning electron microscopy with energy dispersive X-ray spectroscopy(SEM-EDX). The results show that the microstructure of direct chill semicontinuous casting ingot of the 7B04 alloy contains a large number of constituents in the form of dendritic networks that consist of nonequilibrium eutectic and Fe-containing phases. The nonequilibrium eutectic contains Al, Zn, Mg and Cu, and the Fe-containing phases include two kinds of phases, one containing Al, Fe, Mn and Cu, and the other having Al, Fe, Mn, Cr, Si and Cu. The melting point of the nonequilibrium eutectic is 478 ℃ for the casting ingot of the 7B04 alloy which is usually considered as its overheating temperature. During industrial homogenization treatment processing at 470 ℃, the nonequilibrium eutectic dissolves into the matrix of this alloy partly, and the remainder transforms into Al2CuMg phase that cannot be dissolved into the matrix at that temperature completely. The melting point of the Al2CuMg phase which can dissolve into the matrix completely by slow heating is about 490 ℃. The overheating temperature of this high strength aluminum alloy can rise to 500-520 ℃. By means of special multi-stage homogenization, the temperature of the homogenization treatment of the ingot of the 7B04 high strength aluminum alloy can reach 500 ℃ without overheating.     

采用近终形铸造制备高强6xxx铝合金控制臂

采用近终形铸锭配合热锻工艺制备高强6xxx铝合金控制臂。首先设计近终形铝合金锭坯的形状,采用Procast商业软件模拟研究近终形铝合金铸锭的铸造过程。结果表明,近终形铝合金铸锭的收缩行为与铸锭形状相关,经模拟计算优化后,铸造出无缺陷的近终形6xxx铝合金铸锭。为了获得优异的锻件性能,研究了6xxx铝合金的热压缩行为。结果表明,锻件组织中的亚晶百分数与Z参数值相关;中等Z参数（1．09×10^16MS^-1）有利于获得较高的亚晶百分数,从而保证锻件产品具有更优的性能。     

Technical parameters in electromagnetic continuous casting of aluminum alloy

1　INTRODUCTIONElectromagneticcasting (EMC)isanadvancedmaterialprocessingtechniqueinventedbyGetselev[1]andhasbeenwidelyusedintheworldbecauseitsproductshavetheadvantagesofsmoothsurface ,ho mogeneousmicrostructureandgoodworkability[2 ,3] .ElectromagneticcontinuouscastingofsteelisanewtypemethodbroughtforwardbyVives[4 6 ] thatcom binedtheelectromagneticfieldwithcontinuouscast ingtechnique .Itisalsoanewideatoapplythismethodintotheshapingprocessofaluminumalloytoimprovethesurfaceandinnerquality…     

电磁铸造2E12铝合金的铸态组织与力学性能

分别采用电磁铸造和普通连铸技术制备了2E12铝合金连铸锭.通过显微组织和力学性能的对比分析,研究施加电磁场对2E12铝合金连铸过程及铸锭性能的影响.结果表明,使用电磁铸造技术制备的2E12铝合金铸锭具有良好的表面质量和内部组织,以及优良的力学性能.其中,电磁铸造方法获得的2E12铝合金铸锭相对于普通连续铸造铸锭晶粒平均尺寸由58 μm减小至36 μm,抗拉强度提高了9.08%,伸长率提高了61.58%,断裂方式为准解理断裂.     

EFFECT OF LOW-FREQUENCY ELECTROMAGNETIC FIELD ON THE AS-CASTING MICROSTRUCTURES AND MECHANICAL PROPERTIES OF HDC 2024 ALUMINUM ALLOY

The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm× 200 mm were produced by the conventional horizontal chill casting process and low frequency electromagnetic horizontal chill casting processre- spectively. The as-cast structures and the mechanical property of the ingots were examined. The results showed that the low frequency electromagnetic field could sub- stantially refine the microstructures and pronouncedly reduce the macrosegregation in the horizontal direct chill casting process. Moreover, the surface quality of the ingot was prominently improved by the low frequency electromagnetic field. The fracture strength and elongation percentage of the ingot was increased with the low frequency electromagnetic field.     

Effect of casting speed on surface quality of horizontal direct chill casting 7075 aluminum alloy ingot

7075 aluminum alloy ingot with the diameter of 100 mm has been produced by hor-izontal direct chill casting in different casting speed. The effect of the casting speed on the ingot surface and subsurface layer was studied by surface observation and subsurface structure analysis. It was found that increasing the casting speed results in the adding of segregation knots in the ingot surface. The thickness of the dendrite microstructure layer in the subsurface reduces with increasing the casting speed. And the ...     

微型杯突试验法在超高强度铝合金中的应用

采用一种新型在线无损检测试验方法-微型杯突试验法测定超高强度铝合金7150-T7751的抗拉强度,并分析加载速率和试样厚度对试验结果的影响。结果表明,超高强度铝合金7150-T7751微型杯突试验的最大载荷与常规单轴拉伸试验抗拉强度之间具有良好的线性关系;最佳加载速率为0.33 mm/min;最佳试样厚度纵向为0.6 mm,横向为0.8 mm。