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.     

燃烧合成法制备的Al2O3基多孔陶瓷

研究了Al2O3-TiC和Al2O3-TiB2两个体系的多孔陶瓷的制备过程,分析和讨论了产物的相组成、显微结构及成型性以及影响多孔陶瓷性能,如孔径大小、耐腐蚀性能和压缩强度的诸多因素.实验结果表明:布料时有序地改变反应物料的化学组成,可以在产物中不同区域产生不同尺寸的孔洞,形成梯度多孔陶瓷.利用燃烧合成法,可制备出孔径尺寸为1～500μm、酸碱腐蚀质量损失率小于2%、压缩强度为10 MPa左右的多孔陶瓷.     

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。     

Effect of trace rare earth element Er on high pure Al

1　INTRODUCTIONAsit swellknown ,Chinaisrichinrareearths ,whoseprovedreservesare 80 %ofthetotalreservesoftheworld ,rankingfirstintheworld .Atpresent,theresearchandapplicationofREinsteel&ironareratherprofoundinChina .ThoughtheapplicationandstudiesaboutREinaluminumanditsalloysbeganearly ,it snotuntillateinthe 1970 sthattheinvesti gationandexploitationbeganonalargescaleandgraduallycametoaclimax[13] .Inthepast ,there searchofREaluminummainlyfocusedontheapplica tionofsomeelementssuchasLa ,…     

Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15合金的非晶和晶态薄带吸氢行为研究

研究两种不同成分具有较大过冷液相区的四元合金Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15，非晶和晶态薄带吸氢行为，结果表qt两种薄带的吸氢量均随着温度的升高而增大，非晶薄带的吸氢量要小于同等条件下的晶态薄带的吸氢量且只有在673K吸氢后形成了氢化物，Zr65Al7.5Ni10Cu17.5非晶和晶态薄带吸氢后分别生成了Zr2NiH4.7和ZrH2；而Zr65Al10Ni10Cu15非晶和晶态两种薄带最后生成的氢化物同为ZrH2。     

多功能行星变速箱的研制及应用

多功能行星变速箱是广泛应用于工程车辆及其它行业的一种专用传动装置.本文介绍了该类变速箱的结构、工作原理及研制中的几个关键技术问题.研制的多功能行星变速箱系列产品已在石油行业应用多年,替代了进口产品,取得了良好的使用效果.