铝板带材表面油污的控制

分析了用四辊轧机轧制纯铝板带材表面产生油污的原因;讨论了控制方法。增设二次吹扫装置、控制工艺润滑油的质量和退火温度,可以避免铝板带材表面产生油污     

低温退火对累积叠轧焊纯铝板材表面剪切织构的影响

在室温、无润滑条件下,对退火态AA1070工业纯铝板材进行不同道次的累积叠轧焊合试验,然后分别取1道次和3道次板材进行不同温度30 min的低温退火处理.结果表明,同一道次的板材随退火温度的变化,其剪切织构强度有先增加再降低的趋势;不同道次的板材,剪切织构强度随温度升高的幅度不一样.     

离心轧辊冷型表面涂料的选用

离心轧辊冷型表面涂覆是轧辊生产过程中非常重要的一环,如涂料选用不当,很可能会造成成批大量的问题轧辊或轧辊废品,通过三种不同的涂料配比和性能特点的分析,指导轧辊生产厂家应该如何选用适合的轧辊涂料,以保障正常生产。     

不同温度复合条件下Ag／Cu双金属板的分离强度

通过轧制复合方法，在不同温度条件下制备了Ag／Cu双金属板，研究了剥离载荷作用下分离强度与复合温度的关系，测定了复合基体的硬度并观察了分离界面形貌。结果表明：350℃复合的试样因具有较大面积的异种金属冶金结合区域而导致其分离强度较高；低于350℃复合试样的冶金结合区域减少，高于350℃复合试样的金属表面趋向于被连续分布的氧化物隔离，这两种情况均会使分离强度下降。     

Investigation on Temperature Change of Cold Magnesium Alloy Strips Rolling Process with Heated Roll

Magnesium alloy strips are widely used in aerospace, automotive industry, etc., which are difficult to produce through cold forming process due to their poor deformation ability. In this article, we studied whether the rolling process with heated roll could be used to roll cold magnesium alloy strips. Thermal-mechanical finite element simulation of the rolling process, using heated roll and cold strips to produce the magnesium alloy strips, was carried out. Influences of roll temperature, rolling velocity, rolling reduction ratio, and initial strip thickness on the thermal field and the mean temperature of magnesium alloy strips were analyzed. Both the heated area in strips in rolling deformation zone and the mean temperature of strips at exit of rolling deformation zone increase with increasing the roll temperature and/or rolling reduction ratio, and/or with decreasing the rolling velocity and/or initial strip thickness. Finally, a formula was developed to predict the mean temperature of strips under different rolling conditions, which also could be used to calculate the critical value of parameters in rolling process.     

The Influence of Carbon Nanotube and Roll Bonding Parameters on the Bond Strength of Al Sheets

This study investigates the bond strength of aluminum sheets subjected to the roll bonding process in the presence of multiwall carbon nanotubes (MWCNTs). The effects of MWCNTs dispersion, thickness reduction, weight fraction of MWCNTs at the interface, and rolling temperature on the bond strength of the commercial pure aluminum sheets are studied. The peeling test is used to evaluate the bond strength of aluminum sheets. Optical microscopy and scanning electron microscopy are also used to evaluate the surface conditions of the peeled surfaces. Results indicate that, compared to the spread method, using the solution dispersion method to disperse MWCNTs reduces aluminum sheet’s bond strength. Also, the presence of MWCNTs reduces the sheet’s bond strength compared to aluminum sheets at a constant thickness reduction. However, bond strength is increased with higher thickness reductions in the presence or absence of MWCNTs. It is also shown that increasing the entry temperature improves bond strength, but that bond strength enhancement is lower in aluminum-MWCNTs sheets than in aluminum-aluminum sheets.     

累积叠轧1060纯铝微观组织和力学性能的研究

室温条件下对退火态的1060纯铝进行了7道次的累积叠轧（ARB）实验,并通过透射电镜、拉伸、显微硬度实验,研究在多道次的叠轧过程中,1060纯铝内部组织结构的演变和力学性能的变化。结果表明,经过多道次的轧制实验后,由于累积应变的积累和增加能逐渐深入材料的组织内部,晶粒尺寸急剧细化,7道次后超细晶增多,晶粒最小细化到500nm。材料的抗拉强度和显微硬度也显著提高,最高达到197．5MPa和66．2HV。     

Novel Method of Aluminum to Copper Bonding by Cold Spray

Cold spray bonding (CSB) has been proposed as a new method for joining aluminum and copper. At high speeds, solid Al particles impacted the groove between the two substrates to form a bond between Al and Cu. Compared to traditional welding technologies, CSB does not form distinct intermetallic compounds. Large stainless steel particles were introduced into the spray powders as in situ shot peen particles to create a dense Al deposit and to improve the bond strength of joints. It was discovered that introducing shot peen particles significantly improved the flattening ratio of the deposited Al particles. Increasing the proportion of shot peen particles from 0 to 70 vol.% decreased the porosity of the deposits from 12.4 to 0.2%, while the shear strength of joints significantly increased. The tensile test results of the Al-Cu joints demonstrated that cracks were initiated at the interface between the Al and the deposit. The average tensile strength was 71.4 MPa and could reach 81% of the tensile strength of pure Al.     

AA3003合金铸轧板预析出相对再结晶温度、组织的影响

通过光学显微镜、硬度测试仪、扫描电镜、双臂电桥等研究了AA3003铝合金铸轧板经不同均匀化处理后,预析出第二相颗粒对再结晶组织和再结晶温度的影响.试验表明,高温均匀化过程中析出的第二相对冷轧试样的再结晶具有显著的作用.经580℃均匀化处理的试样的再结晶温度降低了大约100℃,并且在520℃退火过程中得到了尺寸梯度很小的细小等轴晶组织.     

冷轧复合AgNi10/Cu/Fe界面结合特征研究

采用等辊径、等辊速冷轧复合技术制备了AgNi10/Cu/Fe三层复合材料,对其界面结合机制进行了研究。复合前对三层材料分别进行再结晶退火,获得均匀的原始组织及相近的硬度,并用钢丝刷清理复合面。利用扫描电镜和能谱仪对复合材料的剥离面进行了形貌观察和成分分析。结果发现,AgNi10/Cu/Fe的界面结合机制主要是裂口机制。各层复合面的硬化层在轧制时开裂,其中较软金属(AgNi10和Cu)从裂口中挤出,与硬金属(Cu和Fe)产生结合;其结合强度分别大于AgNi10和Cu的基体强度。     

Analysis of Bonding Behavior and Critical Reduction of Two-Layer Strips in Clad Cold Rolling Process

In recent years, two-layer metallic sheets have been increasingly used in various industries to create combined functions. Among cladding methods, the cold rolling is most widely used in producing bimetallic sheets. In this research, to thoroughly provide guidelines for cold rolling of bimetal strip, an attempt has been made to develop an analytical model based on upper bound method. Also, the bonding strength and critical reduction were calculated using upper bound theorem and the finite element simulation was used for Al/St bimetallic strip. Finally, an experimental study was run for our model to be verified analytically and numerically. Results show that the bonding strength of strips increases with increasing the total thickness reduction of bimetal strips and because of subsequent occurrence of strips bonding in roll gap, increasing the yield strength of base layer gives rise to critical reduction. Through the study, it becomes clear that the proposed analytical model is applicable for simulating the cold rolling process of the two-layer strips and is capable to broaden our knowledge in manufacturing and production of bimetal strips and sheets.     

扭力轴花键冷打表面完整性研究

目的 针对扭力轴花键冷打表面完整性规律不明的问题,研究冷打成形后花键表面的几何、力学和组织状态演变,为扭力轴花键抗疲劳制造工艺提供参考.方法 将扭力轴花键冷打成形,检测、表征冷打成形后花键的表面形貌及表面粗糙度、残余应力、表层硬化和表层微观组织状态,基于高应变率下的真实应力应变曲线,对表层等效塑性应变进行分析.结果 花...     

Al焊盘表面氧化膜对金丝键合的影响

在半导体制造工艺中，Al焊盘表面的氧化膜会阻碍金丝键合。针对某公司新半导体工艺中出现键合失效问题的芯片，采用SEM，EDS和AES对切片前后的芯片进行了分析，结果发现，切片前后Al焊盘表面的元素成分基本一致。可以认为清洗工艺对金丝键合基本没有影响，它不是导致金丝键合失效的原因；通过AES对焊盘进行深度剖析，在深度接近Al焊盘高度的一半时，氧的含量仍然高达40%左右，如此高含量的氧已经足以将Al完全氧化，其所形成的氧化膜阻碍了金丝键合所必需的金属连接和扩散过程，从而导致键合质量差，甚至无法实现键合。     

面向工业设计的塑料表面铝涂层的结合强度

目的采用电弧喷涂方法在环氧树脂和ABS塑料表面喷涂铝涂层,研究涂层结合强度的影响因素。方法第一组试验是塑料表面喷砂后,喷涂铝涂层;第二组是塑料表面喷砂后,涂覆一层高强度环氧树脂结构胶,再喷涂铝涂层。选择喷涂气体压力、喷涂电流和喷涂距离三因素进行正交试验,采用粘结拉伸法测试结合强度,并用照相法测量铝液和环氧树脂塑料、Q235钢的接触角。结果本试验条件下,二种塑料电弧喷涂铝涂层结合强度的影响因素主次顺序为:空气压力喷涂电流喷涂距离。最优方案是:喷涂气体压力为0.7 MPa,喷涂电流为220 A,喷涂距离为160 mm。未涂覆高强度环氧树脂结构胶的涂层,结合强度最大不超过3 MPa;涂覆高强度环氧树脂结构胶的涂层,结合强度达到近20 MPa。铝液和Q235钢的接触角是45°,和环氧树脂塑料的接触角是135°。结论环氧树脂和ABS塑料表面电弧喷涂铝涂层的结合强度低的主要原因是铝液和它们之间的润湿性差。涂覆高强度环氧树脂结构胶后,喷涂工艺参数对涂层的结合强度影响不明显,结合强度受控于环氧树脂结构胶的粘接作用,使涂层的结合强度显著提高。     

双辊快速凝固0.1～0.5mm铝合金薄带的冷轧性

介绍了AlSi12.5共晶合金和AlMn1.2(3A21)合金用双辊快速凝固法，制得0.28mm和0.45mm薄带，经退火后具有优良的冷轧性；AlSi12.5合金第一道压缩率30％冷轧时薄带边缘无裂缝，冷轧后强度较快凝态薄带提高11％，塑性也有提高。AlMn1.2合金第一道次压缩率50％，边缘无裂缝，冷轧后的强度较常规方法制得的3A21合金Y1硬化态提高40％。     

微结构几何参数对铝合金表面结冰性能的影响

目的 制备具有稳定性的抗结冰表面,并探讨表面微结构几何参数对表面结冰性能的影响.方法 以铝合金为基底材料,采用电火花线切割加工方法,在材料表面构建可控微米级尺寸沟槽与方柱阵列结构,对试件进行润湿性、结冰性能以及稳定性测试.结果 制备的微结构表面超疏水或者近超疏水.微结构表面具有优异的抗结冰性能,且方柱结构表面的抗结冰性...     

铝合金半固态浆料制备工艺参数的研究

通过研究半固态等温搅拌,探讨了不同的搅拌电流和搅拌频率对半固态浆料组织的影响,分析了枝晶断裂程度和断裂部分晶粒尺寸的变化规律,得到了合理的搅拌参数.通过试样金相对比,结果表明,与未经电磁搅拌的半固态浆料相比,经电磁搅拌的浆料初生晶粒更细小、圆整及均匀.电磁搅拌制备的浆料压铸所得的试样力学性能明显优于普通液态压铸试样的力学性能.     

大规格冷轧辊辊径缺陷分析研究

大规格冷轧辊在电渣冶炼过程中会产生液析碳化物及非金属夹杂物,辊坯中存在的液析碳化物和非金属夹杂物是锻造过程产生裂纹性缺陷的诱因。因大规格冷轧辊辊径与辊身的规格差距较大,在辊径锻造过程中会产生裂纹性缺陷并使裂纹性缺陷扩展,最终导致冷轧辊超声检测缺陷超标。     

Passive Behavior of Ultra-Fine-Grained 1050 Aluminum Alloy Produced by Accumulative Roll Bonding in a Borate Buffer Solution

In this study, the effect of the ARB process on the passive behavior of ultra-fine-grained 1050 aluminum alloy in a borate buffer solution(p H 6.0) has been investigated. The result of the microhardness tests revealed that the microhardness values increase with an increasing number of ARB cycles. The potentiodynamic polarization plots revealed that the higher number of cycles for the specimens proceeds with the ARB process rather than annealing yield to lower corrosion and passive current densities and more noble corrosion potential values. Moreover, electrochemical impedance spectroscopy measurements showed that increasing the number of ARB cycles offers better conditions for forming the passive films.