铸态和固溶态Mg-8Li-xAl-yZn合金的显微组织与力学性能

研究Al/Zn比(质量比)对Mg-8Li合金显微组织和力学性能的影响。结果发现,对于铸态Mg-8Li-xAlyZn(x+y=5)合金,当Al/Zn比分别为1:4和2:3时,合金中的第二相主要为AlLi和MgLiZn相;而当Al/Zn比分别为3:2和4:1时,合金中的第二相主要为AlLi和MgLi2Al相。MgLiZn相的分解温度约为300℃,AlLi和MgLi2Al相的分解温度较高,约为350℃。固溶强化是提高Mg-8Li-x Al-y Zn合金强度的主要因素,Mg-8Li-3Al-2Zn合金在350℃固溶处理4 h后具有最佳的综合力学性能,其屈服强度、抗拉强度和伸长率分别为272.5MPa、315.0 MPa和3.4%。     

2024铝合金表面微弧氧化及封孔处理对其疲劳性能的影响

对2024铝合金采用标准硬质氧化(依照我国现行航空用铝合金硬质氧化工艺标准)、微弧氧化、微弧氧化/封孔三种工艺进行处理,在典型应力比(R=-1.0)条件下,对比了三种样品的疲劳性能。结果表明:硬质氧化后的2024铝合金,在低载荷和高载荷下的疲劳性能均比未处理的2024合金差;微弧氧化处理后的样品,在低载荷下的疲劳性能比未处理的2024铝合金好,在高载荷下的疲劳性能则相对较差;微弧氧化并封孔处理后的样品,在高载荷和低载荷下的疲劳性能均比未氧化处理的2024铝合金基材好。     

基于并行工程的压铸产品开发研究

从产品并行设计、可制造性设计评价和产品数据管理方面分析了并行工程技术在压力铸造产品开发过程中的应 用,提出了基于并行工程的压铸产品开发流程。并行工程技术可以有效提高产品设计质量、降低成本和缩短开发周期,将 成为21世纪压铸企业赢得竞争的有力武器。     

Si对AM50力学性能和高温蠕变性能的影响

在基体合金AM50中分别加入Si和Ca,研究了Si和Ca对AM50-xSi合金的微观组织、力学性能及蠕变性能的影响.结果表明:加入Si后,合金高温蠕变性能随Si量的增加而增加并超过了AS41的水平;在AM50-xSi中加入微量Ca以后,合金中的Mg2Si相得到细化,从汉字状转变成颗粒状,室温及150℃拉伸性能明显提高.     

AZ31板料拉深性能的研究

研究了温度及拉深速度对AZ31板材拉深性能的影响,结果表明,温度对采用交叉轧制工艺制备的板材的拉深性能影响明显;板材的拉深性能对拉深速度的敏感性随温度的升高而下降.     

RE和Al5TiB对消失模铸造B319铝合金组织的影响

利用等离子发射光谱仪、能谱仪、X射线衍射以及金相分析等手段，研究了RE和Al5TiB对消失模铸造B319铝合金组织的影响。研究表明，在消失模铸造条件下，RE的质量分数为0.2%时可使B319铝合金的硅相得到较好的变质，组织中存在珊瑚状的Al2Cu相和文字状的α-Fe相及针对的β-Fe相，且Si相和针状β-Fe相可以作为Al2Cu的形核基底。但当ω（RE）=0.3%时，会出现富稀土的金属间化合物La3Al8Si2。RE还会与Ti发生相互作用形成块状稀土化合物，而对组织产生不利影响。研究结果表明，在采用RE变质的情况下，不宜用Al5TiB中间合金作为细化剂。     

Purification effects of glass flux on A356 melt

In order to remove hydrogen and inclusions from A356 alloy melt, a low melting-point glass flux, JDN-Ⅱ ,was devdoped. The results indicated that JDN-Ⅱ flux has distinct effect of purification and protection on A356 alloy melt. When the dosage of the flux was 3 %, the content of hydrogen in A356 melt was only 2.6 mL/kg at 857℃ and 0.7 mL/kg even at 750℃. In the meantime, the mechanical properties of the alloy increase greatly with the covering of 3% JDN-Ⅱ flux. Compared with no flux, the tensile strength of A356 alloy increases by 9.42% and the donaation increases by 22%.The purification mechanism of JDN-Ⅱ glass flux was discussed too.     

Age hardening characteristics and mechanical properties of Mg-3.SDy-4.0Gd-3.1Nd-0.4Zr alloy

Age hardening characteristic and tensile property of Mg-3,5Dy-4.0Gd-3.1Nd-0.4Zr alloy were investigated. The alloy exhibits a considerable age hardening effect up to 250 ℃. Increasing the aging temperature leads to a shorter aging time to reach the peak hardness and a lower peak hardness. The tensile results show that the peak-aged specimens have higher tensile strength at the temperature below 200℃. However, with the increase of temperature further, the tensile strength decreases dramatically and elongation increases drastically. The loss in tensile strength and increase in elongation at high temperature are possibly associated with the instability of secondary precipitates. The fracture mechanism of alloy transfers from intergranular to transgranular with the increase of experimental temperature.     

新型无公害镁合金熔剂的研制

新研制成功的镁合金用熔剂以多种碱金属的氯化物、氟化物为主要成分 ,添加少量无机物 ,使熔剂的熔点、密度、粘度、造渣性达到最佳状态 ,特别是该熔剂加到镁液表面时体积会膨胀 ,释放出惰性气体 ,既减慢了熔剂下沉又增强阻燃效果。 5年的实际使用表明该熔剂使用中释放出来的有害气体远低于规定的排放标准 ,有利于环境保护和操作者健康     

Effect of La and Nd on microstructures and mechanical properties of AZ61 wrought magnesium alloy

Effects of La and Nd addition on the microstructure and mechanical properties of the AZ61 alloy have been investigated. The results show that when La and Nd are added into the AZ61 alloy respectively, the β(Mg17-Al12) phase is refined and granulated, and new phases are formed in the form of small rod-like shape, which are verified as La3 Al12 and Nd3Al11 phase by X-ray diffraction and TEM observation. Microstructure observations show that the effective efficiency of La addition is higher than that of Nd addition, thus the sizes of β(Mg17 Al12) and La3Al11 phase are relatively smaller than those of β(Mg17 Al12 ) and Nd3 Al11 phases in both AZ61 alloy and Nd-containing alloy. The increase of the tensile strength and elongation of AZ61 alloy refers to the existence of small rod-like La3Al11 and Nd3Al11 phases, and fine granulated β(Mg17 Al12 ) phase.