Influence of 1.0 wt% Li on Precipitates in AI-Zn-Mg-Cu Alloy

Microstructure control always plays a key role in enhancing properties of high-strength AI alloys. Attempts to improve the micro-structure of 7000 series alloys by addition of 1.0 wt% Li have been made for a long time, but unsystematically. This article compares the microstructural features of 1.0 wt% Li-containing AI-Zn-Mg-Cu alloy with those of Li-free Al-Zn-Mg-Cu alloy by using differential scanning calorimetric (DSC) techniques, Vickers microhardness and transmission electron microscopy (TEM). The results show the dominance of Guinier Preston (GP) zones, η' or η phases in 1.0 wt% Li-coutaining Al-Zn-Mg-Cu alloy, and confirm the capability of Li to retard the rate of precipitates growth and coarsening.     

20Cr11MoVNbNB 钢高温蠕变过程中沉淀相的粗化动力学

对20Cr11MoVNbNB钢550℃、650℃蠕变过程中的沉淀相研究表明：M23C6和MC型碳化物是该钢的主要沉淀相;M23C6和MC的粗化均符合D-t1/4线性规律、受体扩散和位错扩散综合控制;M23C6的粗化速率比MC的大。     

1.0 wt% Li对Al-Zn-Mg-Cu合金析出相的影响(英文)

Microstructure control always plays a key role in enhancing properties of high-strength Al alloys. Attempts to improve the microstructure of 7000 series alloys by addition of 1.0 wt% Li have been made for a long time, but unsystematically. This article compares the microstructural features of 1.0 wt% Li-containing A1-Zn-Mg-Cu alloy with those of Li-free Al-Zn-Mg-Cu alloy by using differential scanning calorimetric （DSC） techniques, Vickers microhardness and transmission electron microscopy （TEM）. The results show the dominance of Guinier Preston （GP） zones, η＇ or η phases in 1.0 wt% Li-containing Al-Zn-Mg-Cu alloy, and confirm the capability of Li to retard the rate of precipitates growth and coarsening.     

二次硬化超高强度钢中析出强化相HRTEM研究

使用高分辨透射电子显微镜(HRTEM)对高Co-Ni超高强度钢AetMet100在482℃/5h回火后的析出强化相进行研究,对高分辨格子像进行傅立叶变换得到FFT花样并进行标定,从而确定强化相。试验结果发现,在Aet-Met100钢马氏体基体上同时存在两种形态的弥散析出强化相:一种是已有很多报道的棒状M2C碳化物,长度约9.6nm,直径约3.1nm,与基体的取向关系为(01)M∥(001)M2C,[010]M∥[100]M2C;另一种是椭球状的Fe2Mo金属间化合物(Laves相),直径约6.5nm,与基体的取向关系为(2  )M∥(001)L,[111]M∥[100]L。这两种第二相尺寸相当,均为基体的强化相。     

碳含量对15-5PH沉淀硬化不锈钢板材的组织与性能的影响

采用真空感应炉试制3炉不同碳含量的15-5PH沉淀硬化不锈钢,通过热模拟的方法确定了该钢的板材最佳轧制温度区间为900～1100℃,研究了碳含量对钢的相变点温度及力学性能的影响,并观察了时效态的微观组织.结果表明,随着含碳量的增加钢的相变点温度逐渐降低,在时效处理后含碳量较低的1#钢强度均高于2#钢和3#钢,且具有良好...     

冷轧变形对Inconel 718合金δ相γ″相析出行为的影响

采用Ｘ射线衍射技术测定了冷轧Ｉｎｃｏｎｅｌ７１８合金在８６０℃加热温度下的δ相和γ″相含量，研究了冷轧变形对δ相和γ″相析出行为的影响。结果表明，冷轧变形影响δ相的析出形貌，随冷轧变形量增加，δ相由针状向颗粒状转变。δ相析出的重量百分数与时间的关系符合Ａｖｒａｍｉ方程，随冷轧变形量增加，ｎ值减小，α值增加。在８６０℃加热温度下，等温１５ｍｉｎ时已有γ″相析出，随时间增加，γ″相含量增加，达到最大值后又降低。在试验中给定的时间条件下，随冷轧变形量增加，γ″相含量降低，而δ相含量增加。