铝合金铸锻联合成形工艺毛坯冲制质量控制研究

目的提高铝合金铸锻联合成形工艺毛坯冲制良品率。方法采用优化模具设计、设备配置,增加模具保温、坯料预润滑和坯料预处理工序等综合治理方法,开展生产实验研究。结果铝合金铸锻联合成形工艺毛坯冲制良品率由原来的不足85.63%,提高到了97%的稳定水平。结论7A04铸铝坯料的冲制成形条件,比7A04挤压棒材的冲制成形条件要求高,用7A04铝合金铸造坯料代替7A04铝合金棒材冲制工件时,必须对毛坯冲制成形工艺进行细致的完善。     

弹体毛坯热冲拔工艺

目的设计弹体毛坯热冲拔成形工艺方案。方法将冲子压入加热后的钢坯,使钢坯在压力作用下充满模腔,压成盂形,然后套在引伸冲子通过一串直径逐渐缩小的模圈,使弹体拉长、直径减小、壁厚减薄,获得合理的弹体毛坯尺寸,生产出合格毛坯。分析弹体毛坯冲拔成形原理、温度控制、工装设计及冲拔过程中的金属流动规律,根据体积不变原理,计算出冲拔毛坯尺寸。结果通过批量试制,根据冲拔过程中常见问题的控制措施,优化了冲拔工艺参数,实现了弹体毛坯热冲拔成形。结论通过冲拔原理分析、毛坯及工装设计,形成了热冲拔设计规范,该弹体毛坯热冲拔工艺可行。     

轴套镦挤成形过程的计算机模拟与工艺优化

通过计算机模拟带有锥孔大法兰套零件镦挤成形过程，研究该类零件镦挤成形中的金属流动规律及在形条件，得出在满足成形要求及耗能最小的前提下，最佳的毛坯形状和工艺，为该类零件镦挤成形工艺的制定提供了科学依据。     

弹体毛坯热收口成形工艺研究

目的设计弹体毛坯一次热收口成形工艺方案。方法将冲压成空心、变壁厚、桶状的毛坯,经过外皮粗车后进行收口变形,获得合理的弹体弧形部,生产出了合格毛坯。研究了弹体毛坯收口成形原理、温度控制、工装设计以及收口过程中的金属流动规律,根据体积不变原理,计算了收口前粗车毛坯尺寸。结果通过批量试制,根据收口过程中常见问题的控制措施,优化了收口工艺参数,实现了毛坯的一次热收口成形。结论通过收口原理分析、毛坯及工装设计,形成了毛坯一次收口设计规范,该弹体毛坯一次热收口工艺可行。     

7A04铝合金碗形件的闭式模锻

通过对碗形件产品结构的分析,提出了闭式模锻成形的工艺方案。确定了毛坯图、工艺流程和工艺参数,设计了模具结构,在上模内角和退料圈上分别加了排气孔,以确保毛坯充满型腔。工艺试验结果表明,毛坯成形完全,采用闭式模锻成形碗形件工艺可行,现已进行了大量的实际生产应用。     

铬青铜厚板零件的旋压加工

利用加工实例论证了旋压加工空心厚壁回转体铬青铜零件的加工方案。结果表明,采用“普旋与强旋相结合辅以热旋”的复合方案旋压成形零件,可以避免零件内外表面出现疲劳裂纹,提高贴膜精度,缩短了生产周期,更为科学、快速有效。“普旋与强旋相结合辅以热旋”的复合方案旋压加工空心回转体厚板铬青铜零件的经验,可以推广到类似产品的旋压加工中去,具有一定的实用性。     

应用有限元优化设计球磨机回转体端盖锥角角度

球磨机设计过程中回转体结构强度,是否能满足生产要求,是球磨机设计的关键。利用ANSYS有限元软件,对Φ5.5×8.5m溢流型球磨机回转体在其他参数不变的情况下,回转体端盖锥角角度不同时回转体结构强度的变化,对比分析结果,得到最合理的回转体端盖锥角角度。     

基于正交试验的拉深旋压制杯工艺参数研究

对杯形毛坯的旋压成形工艺进行了研究,以期获得最佳的工艺参数。首先采用正交试验的方法,对旋压杯形毛坯的关键工艺参数进行分析;然后采用综合平衡分析法对工艺参数组合进行了优化,最后通过实际的旋压试验对所获得的优化工艺参数组合进行了验证。结果表明,采用综合平衡分析进行的工艺参数优化,可以制造出能够满足后续内齿轮旋压要求的杯形毛坯。     

双向凸台皮带轮冲锻成形有限元分析

根据皮带轮壁厚不均匀且带有双向凸台的结构特点,对其进行冲锻成形工艺研究。利用有限元软件Deform-3D对冲锻阶段金属的流动、成形缺陷及成形载荷进行模拟分析,并采取在冲锻模上模增加不同高度分流槽的形式来降低成形载荷。结果表明,对于双向凸台皮带轮可以采用冲锻成形工艺来成形;在分流槽高度为2mm时,成形效果良好,成形载荷较小。     

壳体冲压工艺及模具设计

通过对壳体冲压工艺进行分析,介绍了毛坯直径和拉深次数的计算方法,通过多次拉深、锥部拉深和变薄拉深,成形出表面质量理想的壳体零件。     

7×××系空心铝型材挤压横向焊缝的研究

目前高速列车的承载结构主要采用7×××系铝合金挤压型材。在铝型材连续挤压生产过程中,2根相邻挤压坯料间的界面会在型材内部形成横向焊缝,而横向焊缝将导致型材性能下降,需要对包含横向焊缝区域的型材进行切除,显著降低了产品的成品率。由于7×××系铝合金硬度较高,材料流动性能较差,所以型材中横向焊缝的延伸长度会大大增加,特别是空心型材中横向焊缝延伸长度增加更为明显,严重影响了产品成品率,因此,开展对7×××系空心铝型材挤压横向焊缝的相关研究具有非常重要的工程意义。回顾了国内外挤压横向焊缝的研究现状,指出了目前该方面研究尚存在的问题,并提出了今后的发展方向。针对7×××系空心铝型材挤压横向焊缝研究中存在的问题,系统研究了空心铝型材横向焊缝的宏观形貌、微观组织等,揭示了挤压工艺参数和模具结构参数对横向焊缝延伸长度的影响规律。结果表明,适当减小挤压比以及增大挤压速度可以有效减小横向焊缝延伸长度,但挤压温度对横向焊缝长度的影响并不明显。     

Study of the formation of chromate conversion coatings on Alclad 2024 aluminum alloy using spectroscopic ellipsometry

The influence of pH of a chromate bath on the morphological and chemical properties of a chromate conversion coating, formed on Alclad 2024-T3 aluminum alloy, has been investigated by variable angle spectroscopic ellipsometry in the visible and infra-red regions. Other techniques such as glow discharge optical emission spectroscopy, transmission and scanning electron microscopy, atomic force microscopy and Auger electron spectroscopy have been used in order to confirm and sustain the results obtained with this technique. The combination of different analytical methods showed a decrease in thickness together with changes in the morphology and chemical composition of the chromate film when the pH is increased from 1.2 to 2.4. Although the complexity of the chromate system and the pronounced roughness of commercial rolled aluminum limit the accuracy of spectroscopic ellipsometry, it is demonstrated that this technique can be usefully applied to the study of thin chromate films formed on industrially relevant aluminum products.     

铝塑泡罩包装机器视觉在线检测系统

介绍了一套基于机器视觉的铝塑泡罩包装实时检测系统。可识别出漏装、残缺、裂纹和有异物等不合格产品，并具有剔除功能。     

2024铝合金的一种新时效制度

通过对２０２４铝合金在不同时效制度下硬度和导电率的测试及统计分析,提出了用于替代室温下自然时效的一种新时效制度,对两种时效制度下的２０２４铝合金进行了拉伸、疲劳、腐蚀、疲劳裂主展速率和扩展寿命的对比试验及统计分析,证明两种时效下的材料机械性能无显著差异,新时效制度的２０２４铝全金完全满足适航要求,这 新时效制度可大在缩短飞机结构停场修理时间,给飞机维修公司和航空公司带来较高的经济效益。     

Bubble‐Sheet‐Like Interface Design with an Ultrastable Solid Electrolyte Layer for High‐Performance Dual‐Ion Batteries

In this work, a bubble‐sheet‐like hollow interface design on Al foil anode to improve the cycling stability and rate performance of aluminum anode based dual‐ion battery is reported, in which, a carbon‐coated hollow aluminum anode is used as both anode materials and current collector. This anode structure can guide the alloying position inside the hollow nanospheres, and also confine the alloy sizes within the hollow nanospheres, resulting in significantly restricted volumetric expansion and ultrastable solid electrolyte interface (SEI). As a result, the battery demonstrates an excellent long‐term cycling stability within 1500 cycles with ≈99% capacity retention at 2 C. Moreover, this cell displays an energy density of 169 Wh kg^?1 even at high power density of 2113 W kg^?1 (10 C, charge and discharge within 6 min), which is much higher than most of conventional lithium ion batteries. The interfacial engineering strategy shown in this work to stabilize SEI layer and control the alloy forming position could be generalized to promote the research development of metal anodes based battery systems.     

Microstructural characterization and wear behavior of in situ TiC/7075 composites synthesized by displacement reactions and spray forming

A novel in situ reaction technique is developed to prepare TiC/7075 composites. This technique provides a new approach overcoming the problems of loss and agglomeration of reinforcement particles when they are in situ formed in a molten metal first and then injected into the spray cone of molten droplets during the spray forming process. Experimental results have shown that the presence of strip or rectangular-like Al₃Ti, which is detrimental not only to the fracture toughness, but also to the stability of the microstructure, can be avoided completely from the final product by using a proper Ti:C molar ratio in the Ti-C-Al performs. The mechanisms of formation or absence of Al₃Ti phase in the TiC/7075 composites are explained based on thermodynamics of the system. The modification of the microstructure of the spray-formed 7075 alloy can be understood in the light of atomic diffusion. The wear results showed that the wear rates of the spray-formed 7075 alloy and its composites increased with applied loads. At higher applied loads, the 7075 alloy exhibited superior wear resistance than that of the composites. This is attributed to increased microcracking tendency of the composites than the matrix alloy.     

Verbund‐Gießschmieden hybrider Aluminiumbauteile

In compound‐cast‐forging of hybrid aluminum parts the positive characteristics of casting and forging processes as well as the different materials are combined. This makes it possible to produce components with complex geometries and different local characteristics. Component areas with high complexity (e. g. with an undercut) are cast, areas that are exposed to high mechanical stresses, are forged. In the conducted investigations a preformed, massive formed semi‐finished part out of a wrought aluminum alloy was joined with a die‐cast aluminum alloy by casting and forming from the casting temperature in one cast‐forging process. The results of the studies show a good joining quality of cast‐forged components made of different aluminum alloys.     

铝合金表面激光熔覆铜镍合金涂层的组织、硬度与耐蚀特性研究

为提升铝合金材料的耐蚀性能,探究铝合金与合金熔覆层间的结合机理,本文利用激光熔覆技术在5083铝合金表面制备了不同Ni含量的铜镍合金熔覆层,并利用扫描电子显微镜、X射线衍射分析、硬度测试与电化学性能测试技术,分析了不同Ni含量的铜镍合金熔覆层相组成与组织形貌、铜镍合金熔覆层与铝合金基体的界面组织形貌,绘制了铝元素扩散曲线,分析了海水腐蚀过程中铜镍合金熔覆层的极化曲线。实验结果表明：所制备的铜镍合金熔覆层形貌良好无缺陷,熔覆层由网络状枝晶组成。对合金熔覆层进行XRD分析发现熔覆层主要由AlNi₃与CuNi两相组成。结合SEM、EDS分析,发现合金熔覆层的网络状枝晶为富铝相,即AlNi₃,晶间相为CuNi相。在硬度测试中,由于AlNi₃硬质相的生成,熔覆层硬度得到了提升且随着铝的向上扩散呈现一定的规律,电化学检测结果表明,铜镍合金熔覆层具有比5083铝合金更高的自腐蚀电位和较小的自腐蚀电流密度,可以有效提升5083铝合金在海水环境中的耐蚀性。     

Spectroscopic studies of the ionic liquid during the electrodeposition of Al-Ti alloy in 1-ethyl-3-methylimidazolium chloride melt

A new approach for the formation of Al-Ti alloy in 1-ethyl-3-methylimidazolium chloride (EmimCl) was investigated. The dissolution of titanium electrodes in presence of EmimCl:AlCl₃ was performed at various potentials to understand the effect of voltage on the reaction rate. It was observed that at low potentials, the presence of titanium hinders the reaction and diminishes the formation of aluminum and aluminum-titanium alloy at the cathode. However, at higher potentials there was substantial formation of Al₃Ti alloy. To understand the reaction mechanism during the electrolysis, the electrolyte was characterized using Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy (UV-vis) and nuclear magnetic resonance (NMR) techniques. The material on the cathode was characterized using scanning electron microscope (SEM) and Energy dispersive X-ray (EDX) techniques. From the above analysis it was found that titanium forms a complex with aluminum and also assists in formation of AlCl₄⁻ phase in the acidic ionic liquid.     

7075铝合金瞬时腐蚀速率的计算和试验验证

针对铝合金腐蚀平均速率与瞬时速率的差异,根据腐蚀过程中试样横截面的变化与欧姆电阻的对应关系,建立了新的腐蚀速率计算方法.将试样全浸和半浸在腐蚀溶液中,分别测定了7075铝合金电阻随时间的变化,并由腐蚀速率计算公式获得了对应的腐蚀速率与时间的关系.结果表明,全浸6h前铝合金腐蚀速率随时间线性减小,接下来经历一个平坦区,25h后腐蚀速率又稍微增加.推断全浸6h之前铝合金表面主要发生点蚀,接下来是晶间腐蚀,25h之后进入剥蚀的发展期.铝合金半浸于电解液中的腐蚀速率随时间的变化趋势与全浸于溶液中相似.