深冲铝板中的再结晶织构与选择生长

利用电子显微分析（TE）和ODF织均分析，研究了纵横轧制铝板再结晶退火前后的织构和再结晶过程．直接观察到再结晶过程中的选择长大，经电子衍射分析了新晶粒的取向，并通过极图分析了各织构组分＜111＞间的关系结果表明，纵横轧制铝板再结晶过程中存在选择生长现象，并最终决定再结晶织构；面心立方金属中这种取向关系约为40°＜111＞     

激光熔覆用高硬度铁基合金的研究与应用

研究了激光熔覆Fe-Ni-Cr—B—Si合金粉末时粉末中的碳含量对于熔覆层组织、开裂敏感性、硬度和硬度均匀性的影响。结果表明，粉末含碳量的微小变化能显著改变熔覆层的组织和性能；在相同工艺条件下，粉末含碳量在一定范围内可显著提高熔覆层的硬度、降低熔覆层开裂敏感性，从而获得高硬度无裂纹的熔覆层；碳含量的增加可提高熔覆层的硬度均匀性。本文还报道了用自制Fe基合金粉末成功修复大型轧辊的实例。     

Ti、B、Sr、RE联合细化及变质对A356铝合金微观组织的影响

采用金相显微镜、SEM、EDAX等试验方法,研究添加Ti、B、Sr、RE元素细化及变质对A356铝合金显微组织的影响,得出RE的添加并未与合金中的Mg形成高Mg含量化合物,Mg的分布仍很均匀,同时含铁相得到细化;对于0.10%Ti细化的A356铝合金,RE的添加使二次枝晶间距明显减小;0.01%Ti与0.03%B联合细化对A356铝合金的细化作用明显优于0.10%Ti的细化作用,晶粒为细小等轴晶,且Al-Fe-Si-Mg、Al-Si-RE相得到明显的细化;Ti、B、Sr、RE联合细化及变质的合金获得了最佳的硅颗粒变质效果。     

Effects of different tempers on precipitation hardening of 6000 series aluminium alloys

By means of Vickers hardness,mechanical property and formability tests,the effects of different tempers on precipitation hardening of 6000 series aluminium alloys for automotive body sheets were investigated.The results indicate that the short-time pre-aging at 170℃makes for subsequent artificial aging precipitation hardening.With the increase of pre-aging time,the artificial aging hardenability increases.The aging hardening rate reaches the maximum when pre-aging time is up to 10 min,and then it decreases.The short-time pre-aging at 170℃benefits sheets to obtain lower strength under delivery condition and consequently to improve stamping formability of automotive body sheets.The effects of different tempers on precipitation hardening are much more obvious than those of the alloying elements.It is a good treatment schedule to perform pre-aging for 5 min at 170℃right after solution treatment.     

Effect of Zr content on quench sensitivity of AlZnMgCu alloys

The effect of Zr content on quench sensitivity of AlZnMgCu alloys was investigated by mechanical properties testing and microstructure observations. The results show that with the increase of Zr the quench sensitivity relative to hardness and strength increases, while that relative to elongation decreases. From hardness and strength viewpoints, the low quench sensitivity is observed for the Zr-free and 0.05% Zr-containing alloys, which is quite quench sensitive from the ductility viewpoint. The largest quench sensitivity relative to hardness and strength is observed for 0.1% Zr-containing alloy, this is mainly due to large amount of high angle grain boundaries and incoherent Al3Zr dispersoids caused by recrystallization, which may efficiently promote heterogeneous precipitation during air quenching. More than 0.05% Zr can significantly decrease the quench sensitivity relative to ductility, which can be primarily attributed to recrystallization inhibiting and grain refining effects of Zr.     

加钛和加硼方式对铝合金的晶粒细化及其衰退行为的影响

通过对比实验,研究了电解加钛与经Al-Ti、Al-Ti-B中间合金向工业纯铝熔配加钛的晶粒细化效果及其衰退行为,以及Al-B中间合金对电解低钛铝合金的晶粒细化效果及衰退行为的影响,还分析了硼对电解低钛铝合金的晶粒细化和抗衰退行为的影响.结果表明,在钛含量为0.10%和0.15%的条件下,电解加钛晶粒细化作用的衰退速度比熔配加Al-Ti中间合金要慢;熔配加Al-Ti-B中间合金细化晶粒作用的抗衰退能力则明显高于电解加钛和熔配加Al-Ti中间合金;加Al-B中间合金可有效提高电解低钛铝合金的细化效果和抗衰退能力,并使其明显高于电解加钛和熔配加Al-Ti或Al-Ti-B中间合金.     

面向高速切削的CAD模型与CAM编程

对复杂零件进行高速切削加工，往往先借助于CAD软件建立模型用于定义零件外型，然后通过CAM软件生成数控加工程序。CAD和CAM的质量与应用是影响高速切削加工质量的主要因素。深入分析并阐述了建立面向高速切削加工的CAD模型时需注意的事项，及如何合理地选用CAM系统提供的编程策略，以获得完美的走刀路径，生成优化的数控加工程序。并以连杆模具高速加工为例，对面向高速切削的CAD与CAM应用进行了介绍。     

Microstructures and constituents of super-high strength aluminum alloy ingots made through LFEC process

Ingots of a new super-high strength Al-Zn-Mg-Cu-Zr alloy were produced respectively by low frequency electromagnetic casting (LFEC) and by conventional direct chill (DC) casting process. Microstructure and constituents of the ingots were studied. The results indicated that the LFEC process significantly refines microstructure and constituents of the alloy, and to some extent, decreases the area (or volume) fraction of constituents and eutectic structure precipitated at grain boundaries. But, no difference in the type of constituents was observed between LFEC and DC ingots. The results also showed LFEC process can improve the as-cast mechanical properties.     

纳米CeO2单晶的制备与热处理对粒径的影响

以Ce(NO3)3·6H2O为铈源、NH3·H2O为沉淀剂,用化学沉淀法通过对陈化时间的控制,制备了单分散的单晶纳米CeO2粒子,并用XRD、TEM、ED、BET、TG-DTA等测试手段对产物的物相结构、形貌和纳米尺度进行了表征.XRD分析表明,制得的纳米CeO2粒子为萤石结构且晶型比较完整. 通过控制热处理的温度和陈化时间可以控制粒子的大小.TEM和ED分析表明产物颗粒基本为球形,分散性较好且为单晶. 通过TG-DTA结果可以断定所制备的前驱体结构式为CeO2·1/2H2O.     

管接头类冲压件模具调整过程中有关问题的解决

以出水管接头为例，说明了管接头类冲压件在多次拉深过程中的工艺特点，并提出了模具调试过程中拉深颈缩、法兰平面度超差等问题的解决措施。