中间退火对高压阳极电容铝箔织构演变的影响

采用晶体取向分布函数（ODF）研究和分析了中间退火对高压阳极电容铝箔织构演变的影响。研究结果表明,随中间退火温度变化,形变织构分中黄铜取向{011}＜211＞变化不大,中间退火温度增高至450℃时,S取向{123}＜634＞密度降低多,中间退火温度在420℃时,铜取向{112}＜111＞密度具有最大值;在成品退火箔材中,立方织构取向密度胡中退火温度升高而降低,R织构取向密度变化不大。     

冷轧润滑剂对高纯铝箔再结晶立方织构的影响

采用ODF分析法(晶体取向分布函数法)及SEM—EBSD(背散射电子衍射)技术研究和分析了不同冷轧润滑剂下高纯铝再结晶立方织构的形成和发展，结果表明，采用机油和煤油作润滑剂冷轧高纯铝箔时，退火后再结晶织构都是由很强的Cube织构以及弱的R织构组成，但煤油润滑比机油润滑冷轧样品退火后获得强得多的立方织构。再结晶立方织构的形成和发展受冷轧形变织构及显微组织结构不均匀性的影响。煤油润滑时样品中产生了大量的不均匀变形组织——剪切带，带中存在大量的立方取向结构，它们提供了形核条件，强化了再结晶立方织构；而机油润滑时冷轧样品变形比较均匀，很难观察到剪切带组织，也很难发现有立方取向结构，说明形变轧制织构和剪切带中的立方取向结构直接影响并控制着再结晶立方织构的形成和发展。     

热轧3104铝合金的显微组织

应用取向分布函数 (ODF)和透射电镜 (TEM)分析热轧对 3 10 4铝合金织构及显微组织的影响。结果表明 ,热轧后织构类型为 (10 0 ) [uvw] ,其中 (10 0 ) [0 11]旋转立方织构为最强 ,且随形变量增加 ,取向密度增大 ,而相应的立方织构 (10 0 ) [0 0 1]取向密度较弱。TEM形貌像表明 ,在热轧过程中发生了动态回复 ,甚至动态再结晶 ,分布在视野内多而弥散的MnAl6 和α Al1 2 (FeMn) 3Si第二相粒子随形变量增大 ,尺寸逐渐减小 ,在动态再结晶过程中起到了粒子促进形核作用 (PSN)。     

热轧3104铝合金的显微组织

应用取向分布函数(ODF)和透射电镜(TEM)分析热轧对3104铝合金织构及显微组织的影响。结果表明，热轧后织构类型为(100)[uvw]，其中(100)[011]旋转立方织构为最强，且随形变量增加，取向密度增大，而相应的立方织构(100)[001]取向密度较弱。TEM形貌像表明，在热轧过程中发生了动态回复，甚至动态再结晶，分布在视野内多而弥散的MnAl6和α-Al12(FeMn)3Si第二相粒子随形变量增大，尺寸逐渐减小，在动态再结晶过程中起到了粒子促进形核作用(PSN)。     

3004铝合金的再结晶和织构

采用ＯＤＦ织构分析和偏光金相法研究了冷轧后高温快速和常规两种不同再结晶退火制度对３００４合金织构和晶粒组织的影响。结果表明：退火方式的不同对合金织构组分影响不大，但影响各组分之间的相对强弱和分布；高温快速退火有利于立方织构的发展和晶粒的细化，处理后板材中存在更强的立方织构和较弱的残留轧制织构；高温快速中间退火还有利于成品薄板各向异性和深冲制耳率的降低。     

Zr含量对工业纯铝组织及性能的影响

为了发展高性能耐热铝锆合金,采用重力铸造和热挤压方法制备了4种不同成分的铝锆合金,利用光学显微镜、扫描电子显微镜、拉伸机和导电仪等测试手段表征铝锆合金的组织和性能,研究了Zr含量(质量分数0.05%~0.2%)对工业纯铝的组织及性能的影响规律。结果表明:Zr含量较少时,对合金组织细化效果显著;随着Zr含量的增加,对合金组织细化效果衰退,并且出现粗大的Al_(3)Zr相;当Zr含量为0.1%时,合金的拉伸性能最优,{100}面织构最弱,对立方织构抑制效果最强;未加入Zr时,导电率最高,Zr含量为0.05%时,导电率次之,耐热性能最好。     

运用电子背散射衍射技术研究高纯金溅射靶材的微观组织与织构

电子背散射衍射(EBSD)技术是分析高纯金靶材微观组织的有效手段,可以快速高效地定量统计材料的微观组织结构、织构、晶粒尺寸、取向差。运用电子背散射衍射技术,研究通过优化真空熔炼工艺制备的高纯金溅射靶材不同区域的微观组织、晶界取向差和织构。结果表明,高纯金靶材组织由细小的等轴晶组成,平均晶粒尺寸为206 nm,样品在轧制过程中发生再结晶,样品所测得的织构(110)平行于轧面,轧向不确定,为较弱的织构。     

高纯金溅射靶材的微观组织与织构的EBSD研究

运用电子背散射衍射(EBSD)技术,对通过优化真空熔炼工艺制备的高纯金溅射靶材不同区域的微观组织、晶界取向差和织构组分进行了研究。结果表明：高纯金靶材组织由细小的等轴晶组成,平均晶粒尺寸为206nm,样品在轧制过程中发生了再结晶,样品所测得的织构(110)平行于轧面,轧向不确定,为较弱的织构。EBSD技术相较其他分析技术,具有快速高效的定量统计材料的微观组织结构、织构、晶粒尺寸、取向差的特征,是高纯金靶材微观组织的一种有效分析手段。     

深冲用工业纯铝板材的各向异性研究

以1100工业纯铝板材为研究对象, 通过拉伸性能及制耳率测定, 显微组织及取向分布函数ODF分析手段, 探讨了深冲用冷轧工业纯铝板材的力学性能及其各向异性行为。研究结果表明, 随着热处理工艺改变, 最终成品表现出不同的各向异性效果, 通过工艺方案的调整, 板料在560～590 ℃/12 h均匀化工艺下材料织构比例达到较为理想的平衡状态,大大降低了材料的各向异性,板材制耳率低于2%, 达到了成品要求。     

铝硅合金中铁相存在的形态及影响其形成的因素

铁是铝硅合金中最为常见的杂质,通常以β-铁相存在,对合金的力学性能有很大影响.降低铝硅合金中的铁含量,或使铁以α-铁相形式存在,可消除铁的有害影响.目前,减少β-铁相的方法主要有:加入锰、钴、铍等中和元素;熔体过热法;提高冷却速率等.要消除或减少铁在铝硅合金中的有害影响,必须综合考虑施用各种方法.     

等通道挤压纯铝的冷轧织构与组织演变

研究了冷轧形变量对等通道挤压纯铝的形变织构与显微组织的影响。结果表明：当形变量较小时，冷轧使挤压高纯铝的显微组织分布更加均匀。然而，随着形变量的增加，晶粒由等轴向纤维状转变。织构的演变规律为旋转立方织构和{111}<110>向冷轧织构（铜织构、黄铜织构和S织构）转变，同时出现了R织构。由此可见，等通道挤压变形对高纯铝的冷轧组织和织构存在一定的影响。     

退火温度及冷轧压下量对低碳铝镇静钢退火织构的影响

研究了退火温度及冷轧压下量对低碳铝镇静钢退火织构的影响.结果表明,在退火温度700℃、压下量70％时,γ织构明显增强;但压下率进一步增加,γ纤维织构反而减弱,并出现了较强的旋转立方织构.压下量70％和75％时,有利于深冲性能的{111}<110>织构和{112}<110>织构较强,而对冲压性能不利的旋转立方织构{100...     

Flotation of coarse composite particles in mechanical cell vs. the fluidised-bed separator (The HydroFloat™)

In principle, carrying out flotation of coarse and composite particles in a quiescent flow field is decisive to prevent particles detaching from bubbles. To overcome or limit detachment of coarse composite particles from bubbles in flotation, a fluidised bed separator, the HydroFloat™, which provides a quiescent environment has been used, and the results compared to the performance of a mechanical (Denver) cell. Model synthetic composites of quartz (value mineral) in lead borate (gangue) matrix with simple and complex locking texture were used for the study. The flotation behaviour of particles with different locking textures was studied at a coarse size distribution of 250–600 μm in both the HydroFloat separator and the Denver cell. The recovery of composite particles with the different locking textures was analysed on an un-sized and size-by-size basis. Recovery was improved in the HydroFloat separator, with both simple and complex locking composite particles having almost the same recovery. Again, comparison of recovery with the HydroFloat to the Denver cell indicates that the separator greatly out-performs mechanically agitated cells for the upper particle size of about 500 μm, with a significant effect on complex locking texture composites. This is attributed to the minimum or absence of turbulence and minimal froth zone which causes detachment of coarse particles in most conventional cells.     

基于行程长度纹理特征的焦炭显微图像分类算法

在分析焦炭显微图像各向异性光学组织中片状与纤维状显微图像特征的基础上,通过对纹理特征的差异性的研究,提出了一种基于行程长度纹理特征和支持向量机(Support Vector Machine)的焦炭显微图像分类方法。该方法首先计算焦炭显微图像中4个方向上的行程长度矩阵,利用行程长度矩阵求得对图像纹理具有不同表征能力的纹理特征量,通过对各个特征量的数据分析,选取有效特征量组合作为分类器的训练向量,然后用支持向量机对实验样本进行分类。实验结果表明,该方法能够有效地识别出焦炭各向异性组织中纤维状、片状等不同光学组分。     

基于视觉技术的煤岩特征分析与识别

为研究煤岩自动识别技术,提出了一种基于视觉技术的煤岩特征分析与识别方法。首先根据煤和岩石图像分析煤岩纹理差异;然后根据灰度共生矩阵分别计算煤和岩石纹理特征向量;最后选择计算出的纹理特征向量作为神经网络输入来分别识别煤和岩石2种情况。实验结果表明,煤和岩石纹理特征值差别较大,采用能量、对比度、相关性和熵作为特征向量均可实现煤和岩石自动识别,且以熵值作为特征向量的煤岩识别效果最好。     

Prediction of mineral liberation characteristics of comminuted particles of high grade ores

In mineral processing, the liberation of valuable mineral is of key importance in achieving high recoveries from downstream separation processes such as froth flotation and gravity concentration. To quantify mineral liberation, information on ore texture of the parent rock as well as properties of comminuted particles is essential. These properties have been quantified by statistical measures such as the proximity function and covariance function, which were extracted from SEM images of parent rock and particle polished sections, using convenient and efficient image analysis techniques based on Labview™ software. To quantify fully liberated particles, a phase specific line segment function has been introduced and evaluated by placing random line segments on the image. It was also found that the ore texture assumptions made by Barbery are not valid for the high grade sulphide ore tested and the general applicability of these assumptions is therefore questionable. Using the measured information above, predictive liberation models to quantify volumetric grade distribution of particles in 1D and 3D have been developed based on Barbery’s work. Results show that the grade distributions of composite particles predicted from the proposed 1D model is closest to measured data than those of Barbery’s 1D model. The predictions using the proposed 3D model are similar to those predicted from Barbery’s model and are considered more realistic as the model does not rely on assumed ore texture but on measurements made on the parent rock and particle sections.     

Characterisation of coarse composite sphalerite particles with respect to flotation

The flotation response of a typical zinc-lead (Zn/Pb) ore, with respect to coarse composite (sulphide/non-sulphide) particles is reported. The flotation tests were carried out on a selected feed particle size range (−600 + 75 μm, at P₈₀ of 390 μm) and the recovery of Zn composite particles analysed on a size by size basis. The best results were achieved with the use of 75 g/t sodium isopropyl xanthate (SIPX), obtaining a Zn recovery of 77%, with a significant improvement at the coarse end of the particle size distribution. Computerised scanning electron microscope (QEMSCAN) was used to characterise value mineral grain size and degree of liberation, as well as gangue and sphalerite association in particles reporting to both concentrate and tailings. A new characterisation function (Locking ratio, LR) was developed based on the data from the automated mineralogical analysis to characterise particles into two-phase composites with different degree of locking texture (simple and complex). The function, which is based on the mode of occurrence of sphalerite, grain size, proportion and composition of the constituent minerals in each particle, was used to study the flotation response of the particles with different degrees of locking. The results highlight the difference in recoverability of the sphalerite bearing particles with different degrees of locking, with simple locking texture giving higher recovery than complex locking texture, for the same overall liberation.     

不同热处理下SiCp/Al复合材料摩擦磨损性能及机理研究

颗粒增强铝基复合材料因其轻质性和耐磨性,是发展轻量化制动部件的优良备选材料。本研究采用由压力浸渗法制备的SiCp/2024Al复合材料,与GCr15钢球进行了干滑动摩擦磨损实验,探究其在T4和T6热处理以及不同载荷和滑动速度下的磨损机理和摩擦学性能;为进一步探明SiC颗粒加入对磨损机理的影响,与2024铝合金进行了相同的对比实验。结果表明：高硬度SiC颗粒的加入明显提高了材料的耐磨性,T6热处理工艺相较于T4工艺可降低复合材料的摩擦系数和磨损率,SiCp/2024Al复合材料相较于2024铝合金具有更高且稳定的平均摩擦系数,而磨损率和磨损量降低;复合材料的磨损机制主要为剥层磨损,2024铝合金的磨损机制为磨粒磨损,SiC颗粒的加入引起了磨损机理的转变;磨损过程中亚表层颗粒在低速低载情况下较为完整,起保护减磨作用,而在高速高载情况下更易破碎形成微观缺陷,加快亚表层微裂纹的扩展。     

放电等离子烧结制备纳米SiC_p/Al复合材料及组织性能研究

以微米级、纳米级碳化硅(SiC)颗粒和纯铝(Al)粉为原料,通过高能球磨+放电等离子烧结(SPS)工艺制备了不同质量分数的SiC颗粒增强Al基复合材料(SiC_p/Al),研究了SiC颗粒尺寸和含量对复合材料组织性能的影响。结果表明:高能球磨能促进增强颗粒的均匀分布,放电等离子烧结具有烧结温度低、保温时间短的特点,可有效减少甚至避免基体与增强体有害反应的发生。纳米级SiC增强铝基复合材料的颗粒团聚趋势较大,复合材料致密度较低,但是其细晶强化和Orowan强化效果显著,包含源缺陷和源裂纹较少,因此,复合材料硬度和屈服强度相应提高。     

高纯超细氧化铝粉末的制备(Ⅰ)——氧化铝粉纯度的控制

对制备高纯氧化铝粉末过程中杂质的行为进行了分析 ,对采用有机试剂 A屏蔽 Fe3 +除铁进行了理论分析 .试验证明该屏蔽剂可很好地避免 Fe3 + 在中和过程中进入沉淀 ;添加 B可沉淀铅、锌等杂质 ;通过洗涤、煅烧能够有效除去钠 .制得的高纯氧化铝杂质含量 (w/ % ) :Fe0 .0 0 15 ,Si<0 .0 0 0 5 ,Cu 0 .0 0 0 1