共沉淀粉末与混合粉烧结ITO靶材的微观组织结构研究（英文）

磁控溅射ITO靶材制备ITO透明导电薄膜作为平板显示、太阳能电池、气敏元件等电子器件的电极材料,需要ITO靶材具有高纯度、高均匀性、高密度、高导电性的特点。对比研究了ITO共沉淀粉与In_2O_3、SnO_2单体混合粉同炉烧结ITO靶材的微观组织结构差异,如:晶粒尺寸分布、晶粒形貌、元素分布、烧结速率等。结果表明:单体混合粉的烧结速率要比共沉淀粉的烧结速率高,但是前者烧结ITO靶材的微观组织结构不及后者烧结的均匀性好。对比而言,共沉淀粉更容易获得结构组织均匀的ITO靶材,但前提是要合理的设计烧结工艺抑制烧结过程中In_2O_3的分解。研究结果将会对提高ITO靶材微观组织均匀性和减少靶材毒化,进而提高靶材生产效率提供有益的参考。     

Comparing Microstructures of ITO Sputtering Targets Prepared by Tin Doped Indium Oxide Powders and In2O3- SnO2 Mixed Powders

磁控溅射ITO靶材制备ITO透明导电薄膜作为平板显示、太阳能电池、气敏元件等电子器件的电极材料,需要ITO靶材具有高纯度、高均匀性、高密度、高导电性的特点。对比研究了ITO共沉淀粉与In2O3、SnO2单体混合粉同炉烧结ITO靶材的微观组织结构差异,如：晶粒尺寸分布、晶粒形貌、元素分布、烧结速率等。结果表明：单体混合粉的烧结速率要比共沉淀粉的烧结速率高,但是前者烧结ITO靶材的微观组织结构不及后者烧结的均匀性好。对比而言,共沉淀粉更容易获得结构组织均匀的ITO靶材,但前提是要合理的设计烧结工艺抑制烧结过程中In2O3的分解。研究结果将会对提高ITO靶材微观组织均匀性和减少靶材毒化,进而提高靶材生产效率提供有益的参考     

预热爆炸压实烧结纳米ITO陶瓷粉末

改进爆炸实验装置，并利用该装置实施了预热爆炸压实实验。以商业ITO纳米陶瓷粉末为原料，通过压力机将粉末压实到大约50％理论密度的初始压坯，选择预热温度为800℃以上进行爆炸压实，从而获得了致密且晶粒在纳米量级的良好烧结体。结果表明：预热爆炸烧结体微观组织结构均匀，晶粒尺寸分布在200nm左右，且将烧结体在扫描电镜上放大到100，000倍时仍未发现明显孔洞和微裂纹等缺陷。认为宏观塑性变形和晶粒长大是导致良好烧结的2个主要机制。     

放电等离子烧结法制备ITO靶材

采用单相的ITO复合粉末经放电等离子烧结法(SPS)快速制备了ITO靶材.研究了SPS的主要工艺参数对ITO靶材致密化的影响.结果表明:靶材的相对密度随着烧结温度的升高而增大,在1000 ℃时达到最大值;在1000 ℃下烧结,延长保温时间使相对密度降低;在较低的温度下烧结时,延长保温时间有利于提高靶材的致密度;相对密度随着烧结压力的增加而增大;升温速率过快不利于靶材的致密化.对烧结试样的相组成和化学成分研究表明:不同温度下制备的ITO靶材均有少量的SnO_2相析出,并有不同程度的失氧,铟锡的质量分数略大于ITO原粉中铟锡的质量分数.     

高致密ITO靶材制备工艺的研究现状和发展趋势

简述了ITO薄膜的各种性能和主要应用,综述了国内外ITO靶材的主要成形、烧结工艺及其研究现状,概括了ITO靶材的发展趋势.     

ITO陶瓷靶材的制备方法及研究现状

介绍了ITO靶材的各种性能及应用,综述了目前常用的几种靶材成形方法和烧结工艺以及他们的研究现状,并对ITO靶材今后的发展趋势进行了展望。     

纳米级ITO粉体对烧结法制备靶材的影响

采用化学共沉淀法制备ITO前驱物,分别于600及1000℃下热处理前驱物,得到两种ITO粉体.粉体模压成型得到素坯,在400～1550℃内采用烧结法、氧气氛下烧结素坯制备出ITO靶材.对粉体及靶材进行表征和分析,研究了烧结过程中晶粒生长情况、靶材微结构与温度之间关系及靶材的失氧现象.得出600℃粉体为单相ITO固溶体、粒径为15 nm,1000℃粉体有少量SnO2析出、粒径为28 nm且其分散性和晶化程度优于600℃的粉体.两种粉体烧结制备靶材过程符合Coble固相烧结理论,1550℃时晶体出现类似二维成核生长方式的生长台阶.靶材密度随温度升高而增加,1550℃时随保温时间延长而增加.靶材致密化过程由团聚程度及团聚体大小决定,1000℃粉体制备的靶材密度高于600℃粉体所制靶材.两类靶材含氧量均低于理论值,1000℃粉体所制靶材含氧量高于600℃的含氧量.     

升温速率对烧结ITO靶材密度和组织的影响

采用化学共沉淀法制备ITO粉体前驱物,在600℃煅烧粉体前驱物4h,得到粒径为20~30nm的ITO粉体。添加1%的聚乙烯醇(PVA)造粒,模压成型制备ITO靶材素坯,设置不同的升温速率,在1550℃氧气氛下烧结素坯,得到ITO靶材。研究了烧结过程升温速率对ITO靶材密度和微观组织的影响。结果表明,在低温阶段(0~500℃)升温速率为3℃/min,高温阶段(500~1550℃)升温速率为8℃/min时,ITO靶材相对密度为99.58%,孔洞极少,近乎完全致密,且靶材宏观上无裂纹。     

热压烧结ITO靶材物相组成与电子结构研究

采用XRD、XPS对ITO固溶烧结前后物相结构及靶材表面In、Sn、O三元素价态进行表征和研究。结果发现:ITO固溶体中溶质与溶剂离子的半径差异较大是引发掺杂后XRD图谱谱峰偏移的主要原因;而XPS图谱中谱峰偏移则是Sn掺杂导致ITO导带中电子态占有率增加、Fermi能级升高的缘故。研究结果为制备成分、结构均匀的高密度ITO靶材提供了有益的参考。     

成型压力对冷等静压-烧结法制备ITO靶材中孔隙缺陷的影响

孔隙缺陷是影响ITO靶材密度及其均匀性的主要原因。研究冷等静压-常压烧结法制备ITO靶材中孔隙的形成机理及其在成型中的变化过程,分析成型压力(模压和冷等静压)对生坯及靶材孔隙缺陷及相对密度的影响。结果表明:尽管模压压力远低于冷等静压压力,但模压过程对ITO生坯中孔隙缺陷的消除具有重要影响;当模压压力由4 MPa提高到20 MPa时,生坯经200 MPa冷等静压后,孔径在15~45μm区间的孔隙率由1.09%降低为0.2%。实验所用ITO颗粒的屈服压力约为12 MPa。当模压压力小于12 MPa时,生坯中的ITO颗粒仅发生压缩形变;而当其大于12 MPa时,ITO颗粒破碎,致使生坯致密化,从而消除孔隙缺陷。在模压和冷等静压压力分别为24和250 MPa条件下,ITO生坯相对密度达59.3%,烧结后ITO靶材相对密度高达99.1%。     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.     

Microstructures and Mechanical Properties of a Newly Developed Austenitic Heat Resistant Steel

The effect of heat treatment on the microstructures and mechanical properties of a newly developed austenitic heat resistant steel(named as T8 alloy) for ultra-supercritical applications have been studied. Results show that the main phases in the alloy after solution treatment are γ and primary MX. Subsequent aging treatment causes the precipitation of M_(23)C_6 carbides along the grain boundaries and a small number of nanoscale MX inside the grains. In addition, with increasing the aging temperature and time, the morphology of M_(23)C_6 carbides changes from semi-continuous chain to continuous network.Compared with a commercial HR3C alloy, T8 alloy has comparable tensile strength, but higher stress rupture strength. The dominant cracking mechanism of the alloy during tensile test at room temperature is transgranular, while at high temperature, intergranular cracking becomes the main cracking mode, which may be caused by the precipitation of continuous M_(23)C_6 carbides along the grain boundaries. Typical intergranular cracking is the dominant cracking mode of the alloy at all stress rupture tests.     

The 15th Global Foundry Sourcing Conference 2014held in Qingdao China

Organized by Suppliers China Co., Ltd and co-organized by the National Technical Committee 54 on Foundry of Standardization Administration of China, the 15th Global Foundry Sourcing Conference 2014 （hereinafter referred to as FSC 2014） was successfully held on Sep. 23rd in Grand Regency Hotel, Qingdao. More than 500 delegates from home and abroad attended this conference, including over 130 purchasers from 20 countries and 380 domestic and foreign suppliers.     

Secondary Recrystallization Behaviors of Grain-Oriented 6.5 wt% Silicon Steel Sheets Produced by Rolling and Nitriding Processes

By rolling and nitriding processes, 0.23- to 0.3-mm-thick grain-oriented 6.5 wt% silicon steel sheets were produced. The core losses of grain-oriented 6.5 wt% silicon steel at frequencies ranging from 400 Hz to 20 k Hz were lower than that of the grain-oriented 3 wt% silicon steel with the same thickness by 16.6–35.8%. The secondary recrystallization behavior was investigated by scanning electron microscopy, energy-dispersive spectroscopy, and electron backscattered diffraction. The results show that the secondary recrystallization in high-silicon steel sheets develops more completely as the nitrogen content increases after nitriding, secondary recrystallized grain sizes become larger, and the sharpness of Goss texture increases. Because more {110}116 grains in the subsurface and the central layer of the sheets have a lot of 20°–45° high-energy boundaries in addition to Goss grains, {110}116 can be the main component through selective growth during secondary recrystallization when the inhibitor quantity is not enough and inhibitor intensity is weaker. The increases in nitrogen content can increase the inhibitor intensity and hinder abnormal growth of a mount of {110}116 grains and therefore enhance the sharpness of Goss texture.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

Laser Cladded TiCN Coatings on the Surface of Titanium

Laser cladded coatings of TiCN were produced on the surface of titanium. To obtain the optimal techniques, several conditions were tested by varying the laser scanning rate. The choice of shielding gas was also studied. The cladded coatings were then evaluated from the surface mechanics point of view based on their microhardness. The microstructure of some interesting samples was investigated by optical micrographs (OM). The results showed that under the condition of fixed pulse frequency and pulse width, the laser scanning rate and the shielding gas are the main factors influencing the components of coatings. TiCN coatings were decompounded and oxidized during the cladding process in the condition of no shielding gas of N2. X-ray diffraction results indicated that the composite coatings composed of TiCN, TiC, Ti2N, and TiO2 were produced using appropriate techniques. The results indicated that the best condition in terms of the surface microhardness is obtained when the scanning rate is 1.5mm / s, the pulse frequency is 15Hz, the pulse width is 3.0ms, and N2 is chosen as the shielding gas. The microhardness of the composite coatings is about 1331kg · mm - 2, which is about 4 times that of the substrate. The optical micrographs indicated that the cladding zone is made up of TiCN, TiO2, and some interdendritic Ti, but the diffusion zone mainly consists of the dendrites phase, and the cladded depth is about 80?滋m, which is more than 2 times that of the laser nitrided sample. There were no microcracks or air bubbles in the cladded sample, which was cladded using the above optimal techniques.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Microstructure and Mechanical Properties of X80 Pipeline Steel Joints by Friction Stir Welding Under Various Cooling Conditions

X80 pipeline steel plates were friction stir welded(FSW) under air, water, liquid CO_2 + water, and liquid CO_2 cooling conditions, producing defect-free welds. The microstructural evolution and mechanical properties of these FSW joints were studied. Coarse granular bainite was observed in the nugget zone(NZ) under air cooling, and lath bainite and lath martensite increased signifi cantly as the cooling medium temperature reduced. In particular, under the liquid CO_2 cooling condition, a dual phase structure of lath martensite and fi ne ferrite appeared in the NZ. Compared to the case under air cooling, a strong shear texture was identifi ed in the NZs under other rapid cooling conditions, because the partial deformation at elevated temperature was retained through higher cooling rates. Under liquid CO_2 cooling, the highest transverse tensile strength and elongation of the joint reached 92% and 82% of those of the basal metal(BM), respectively, due to the weak tempering softening. A maximum impact energy of up to 93% of that of the BM was obtained in the NZ under liquid CO_2 cooling, which was attributed to the operation of the dual phase of lath martensite and fi ne ferrite.     

INDUSTRY NEWS

China Securities News reported on March 21, 2014： Guangdong Hongtu Wuhan Die Casting Co., Ltd. （Wuhan Hongtu）, a wholly owned subsidiary of Guangdong Hongtu Technology （Holdings） Co., Ltd., held a groundbreaking ceremony recently. With the registered capital of 50 million Yuan, Wuhan Hongtu has a total land area of 100,000 square meters and a plant construction area of 72,000 square meters. It is expected to have a production capacity of about 30,000 tonnes of aluminum castings annually after it is put into production.