5251铝合金H2n和O状态板材生产工艺研究

研究了中温轧制后5251铝合金板材的退火温度和保温时间对板材组织与性能的影响,确定了5251铝合金H2n和O状态的生产工艺及热处理制度.结果表明,按所确定的工艺制度生产的板材,其性能指标达到EN485标准的规定值.     

退火温度对4047铝合金板材组织及性能的影响

试验研究了4047铝合金热轧板和温轧板的力学性能,确定了1.0mm厚4047铝合金板材的退火软化曲线,为确定板材的退火状态性能提供参考依据。     

1100-H24铝合金板材退火工艺研究

采用多因素优选法,试验研究了退火工艺对1100铝合金板材的组织、力学性能的影响。结果表明,在适当的化学成分控制范围内,采用合理的退火温度和保温时间条件退火处理,1100-H24铝合金1.6 mm×1220 mm(厚×宽)铝合金板材的力学性能可以满足电气市场的使用要求。     

汽车用高性能3004铝合金板材生产工艺研究

对汽车用3004铝合金板材的生产工艺进行了研究,通过控制合金化学成分,试验研究冷轧工艺路线、退火温度对3004铝合金板材组织与性能的影响,确定了对热卷采用多道次冷轧至成品厚度板材的工艺路线,成品退火制度为340℃(11+1)h。生产出的0.4 mm厚度板材抗拉强度为180 N/mm2～185 N/mm2,伸长率为19.1%～20%,均超过标准规定值及用户的要求值,深冲性能良好,满足汽车用材的要求。     

3003铝合金O、H24状态大卷材工艺研究

研究了退火温度、保温时间对3003铝合金板材组织与性能的影响,确定了3003铝合金O、H24状态大卷材退火热处理工艺,确定了退火工艺制度。其性能指标达到GB/T3880-1997标准的指标。     

退火工艺对7×××系某铝合金板材组织和性能的影响

为了改善7×××系某铝合金板材的塑性,试验研究了退火工艺参数对7×××系某铝合金冷轧板材组织和力学性能的影响。研究结果表明,7×××系某铝合金冷轧板材,开始再结晶温度为200℃,终了再结晶温度为360℃;最佳完全退火制度为退火温度380℃~390℃,保温1.0 h;可作为制定工业生产7×××系某。O状态某铝合金板材退火工艺制度的基础。     

5052-H32铝合金12.0mm板材厚向氧化色差(组织均匀性)工艺研究

在轧制12 mm厚的5052-H32铝合金板材过程中,由于轧制加工率不足,常导致成品板材厚度方向心部组织与表层组织不一致,不能满足用户的要求。结合生产实际,试验研究热轧道次加工率、中间退火温度和冷轧加工率对5052铝合金板材厚度方向组织均匀性与性能的影响。从而确定5052-H32铝合金板材合理的生产工艺制度,为大生产做技术储备。     

2A12ME铝合金板材的深冲性能研究

研究了化学成分、退火制度、出炉冷却方式对2A12铝合金2.0 mm板材深冲性能的影响,确定了2A12ME板材的最佳Cu含量和生产工艺参数:w(Cu)≤4.5%;退火温度360℃～380℃,保温时间1 h～2 h;退火冷却方式为随炉冷却到200℃出炉。     

5083铝合金H2n状态板材退火工艺研究

研究了退火温度及保温时间对5083铝合金板材组织与性能的影响,退火温度对该板材抗剥落腐蚀性能的影响,板材硬度的变化规律.确定了5083-H2n板材的退火工艺制度.     

退火制度对冷轧和温轧的5083铝合金组织性能的影响

选择冷轧和温轧变形量均为75%的5083铝合金板材进行退火,研究不同退火制度对合金板材组织和性能影响。结果表明,冷轧5083铝合金在200℃退火后发生回复;温轧5083铝合金在200℃退火后发生回复和一定程度再结晶;300℃退火合金的强度大幅度降低,塑性明显提高,且冷轧合金的强度下降幅度比温轧的大;550℃退火时,冷轧和温轧5083铝合金板材的纤维组织消失,再结晶晶粒明显长大,且等轴化。     

Texture and mechanical properties of Al-0.5Mg-1.0Si-0.5Cu alloy sheets manufactured via a cross rolling method

The relationship between the texture and mechanical properties of 6xxx aluminum alloy sheets processed via cross rolling was investigated. The microstructures of the conventional rolled and cross rolled sheets after annealing were analyzed using optical micrographs (OM). The texture distribution across the thickness in the Al-Mg-Si-Cu alloy, conventional rolled sheets, and cross rolled sheets both before and after annealing was investigated via X-ray texture measurements. The texture was analyzed in three layers from the surface to the center of the sheet. The β-fiber texture of the conventional rolled sheet was typical of the texture obtained using aluminumoll ring. After annealing, the typical β-fiber orientations were changed to recrystallization textures: cube{001}〈100〉 and normal direction (ND)-rotated cubes. However, the texture of the cross rolled sheet was composed of an asymmetrical, rolling direction (RD)-rotated cubes. After annealing, the asymmetrical orientations in the cross rolled sheet were changed to a randomized texture. The average R-value of the annealed cross rolled sheets was higher than that of the conventional rolled sheets. The limit dome height (LDH) test results demonstrated that cross rolling is effective in improving the formability of the Al-Mg-Si-Cu alloy sheets.     

Characterization of Microstructure,Mechanical Properties and Formability of Cryorolled AA5083 Alloy Sheets

In this work, microstructure, mechanical properties and formability of cryorolled and annealed AA5083 alloy sheets have been characterized and a comparison has been made with cold rolled and annealed sheets. Five-millimeter-thick sheets of this alloy were cryorolled in multiple passes to a final thickness of 1 mm (80% reduction with a true strain of 1.6). Effect of annealing time and temperature on hardness has been studied, and it has been found that a short annealing at 275 °C for 15 min after cryorolling would yield a good combination of strength and ductility. Microstructural investigations showed that the cryorolled and short annealed samples possess bimodal grain structure which is responsible for better mechanical properties than cold rolled sheets. From the experimentally determined forming limit diagrams, the limit strains of cryorolled sheets have been found to be almost equal to conventional cold rolled and annealed sheets in all modes of deformation. No major differences have been found in strain distribution also. This work clearly demonstrates that cryorolling of AA5083 alloy sheets followed by a short annealing with bimodal grain structure can be used for sheet metal forming applications with higher strength and toughness than conventional sheets without any reduction in formability.     

AZ31B镁合金热拉伸流变应力研究

针对不同加工方法制备的AZ31B镁合金薄板,利用热拉伸试验机和金相显微镜对其在不同温度和变形速率下的流变应力进行了实验研究。结果表明,变形温度和变形速率对热拉伸时镁合金的流变应力有显著影响,峰值流变应力随应变速率的降低和变形温度的升高而降低。峰值流变应力随板材的厚度增加而发生变化,低温时厚度效应较为明显。退火处理对冷轧板的峰值流变应力影响较小,冷轧板可直接用于热加工成形。峰值流变应力变化规律:挤压板>热轧板>冷轧板。     

Warm deep drawing of wrought magnesium alloy sheets produced by semi-solid roll strip-casting process

This paper is concerned with the development of a continuous strip-casting technology to facilitate the manufacture of magnesium sheet alloys economically whilst maintaining high quality. Established in the paper is warm formability of cast magnesium alloy sheets after being hot rolled by semi-solid roll strip-casting process. It has been found that magnesium sheet with 2.0–4.0 mm thickness could be produced at a speed of 25 m/min. Hot rolling and annealing temperatures during hot rolling were also changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microstructures of the crystals of the manufactured wrought magnesium alloys were observed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep-drawing test of the cast magnesium alloy sheets after being hot rolled.     

Recrystallization kinetics and grain growth studies in twin-roll cast strips of commercial purity aluminium (1050) and aluminium-magnesium alloy (5005)

Recrystallization kinetics and grain size distribution have been studied in commercial purity aluminium (1050) and Al-Mg alloy (5005) which had been previously twin-roll cast to thicknesses of 1.5 mm and 3 mm. The samples were annealed at 300 °C for different times up to 20 hours. The index of recrystallization was found to be 3.2 ± 0.2 for each type of material, which implied a three-dimensional nature of recrystallization. The 1.5 mm thick samples had higher nucleation rates and, therefore, a smaller final average recrystallized grain size. The grain size distribution was more stabilised in the 1050 samples than in the 5005 samples, and this may be due to the drag effect of the FeAl₃ particles on the grain boundaries in the commercial aluminium samples. The degree of spread in the distribution of the grain sizes was bigger in samples rolled to 3 mm than those rolled to 1.5 mm. Anisotropy in the microstructure was observed in the 1050 sheets of thickness 3 mm, in that, the average grain size in the rolling direction (RD) was larger than that in the transverse direction (TD). However, during annealing at 500 °C, the 1.5 mm-thick samples of the 1050 sheet preceded the 3.0 mm-thick samples in achieving an equiaxed grain structure.     

Microstructure,texture and grain boundaries character distribution evolution of ferritic stainless steel during rolling process

In order to better understand the texture, microstructure and grain boundaries character distribution evolution of ferritic stainless steel, the texture, microstructure and grain boundaries character distribution of ferritic stainless steel (hot rolled sheet, cold rolled sheet and annealing sheet) with 11 wt%Cr content were studied using X-ray diffraction and electron back scattered diffraction technique. The texture of the hot and cold rolled sheets has a through-thickness texture gradient. In the center layer of the hot and cold rolling sheet, α-fiber texture was observed which was attributed to ideal plane strain deformation. Close to the surface a Gross orientation was detected which was attributed to shear deformation. During annealing, the γ-fiber was formed attributed to recrystallization process. The microstructure of the hot and cold rolled sheets was non-homogeneous through the sheet thickness, while, the microstructure of annealing sheets was homogeneous through the sheet thickness. Grain boundaries character distribution results show that there are many low angle grain boundaries in hot and cold rolled sheets and many high angle grain boundaries and coincidence site lattice after annealing. The above results indicated that the changes in texture are closely related to the grain boundaries type.     

Effect of Annealing Temperature in Al 1145 Alloy Sheets on Formability, Void Coalescence, and Texture Analysis

This paper deals with a combined forming and fracture limit diagram and void coalescence analysis for the aluminum alloy Al 1145 alloy sheets of 1.8 mm thickness, annealed at four different temperatures, namely 200, 250, 300, and 350 °C. At different annealing temperatures these sheets were examined for their effects on microstructure, tensile properties, formability, void coalescence, and texture. Scanning electron microscope (SEM) images taken from the fractured surfaces were examined. The tensile properties and formability of sheet metals were correlated with fractography features and void analysis. The variation of formability parameters, normal anisotropy of sheet metals, and void coalescence parameters were compared with texture analysis.     

润滑对3104铝合金板变形织构的影响

在无润滑(WOL)和润滑(WL)2种轧制条件下,分别对2.3 mm厚的热轧3104铝合金板进行不同压下量的冷轧.应用取向分布函数(ODF)定量计算和分析在不同轧制压下量下润滑对3104铝合金板材沿板厚方向织构演变的影响.结果表明:随着轧制压下量的增加,样品各层的织构组分强度均逐渐增加;无润滑轧制时样品表面层主要织构组分取向密度普遍高于相同压下量下润滑轧制时的取向密度.导致表面层织构组分增强的原因是摩擦引起应变状态改变的结果.     

Effect of initial textures on texture formation in AA 3004 sheets during continuous confined strip shearing and subsequent annealing

The effect of initial textures on the texture formation during continuous confined strip shearing (CCSS) and subsequent annealing was investigated in AA 3004 sheets. The CCSS tools were designed to provide a constant shear strain of the order of 0.5 per pass while preserving the original sheet shape. During the CCSS deformation, the initial texture disappeared, and shear texture components developed. However, the intensity of the shear texture components did not further develop with an increasing number of CCSS passes. The softer initial sample depicting the cube texture displayed the evolution of {111}//ND fiber orientations. Upon recrystallization annealing, the textures developed during CCSS were randomized through the suppression of oriented nucleation and selected growth which generally dominate the evolution of recrystallization texture in cold rolled aluminum alloy sheets.     

铝锂合金自动铆接干涉量及残余应力分析

铝锂合金是航空制造中的新型合金材料,其铆接技术是现代飞机制造重要研究方向。铆接后的铝锂合金板孔的干涉量影响到残余应力分布,为了研究铆接过程与残余应力分布特征之间的关系,利用自动钻铆装备对不同厚度的铝锂合金板进行铆接。使用ABAQUS/Explicit对铝锂合金自动压铆过程进行了仿真,通过试验和仿真的方法分析不同压铆力、铆钉长度、壁板厚度和铆钉材料等组合条件下铝锂合金壁板内部所产生的干涉量,进而推导出各工艺条件下铝锂合金壁板厚度方向上残余应力的分布规律。结果表明,2060-T8铝锂合金壁板孔壁产生的干涉量及沿板厚方向分布的残余应力随压铆力的增大而增大,随铆钉长度的增大而减小,随壁板厚度的增加呈现非单调增长的趋势。壁板总厚度为4.2 mm时,平均干涉量及平均残余应力可以达到最大值。相比于2117-T4铝合金铆钉,采用7050-T3铝合金铆钉压铆后2060-T8铝锂合金壁板产生的平均干涉量降低6%～12%,平均残余应力降低8%～12%。