冷轧及退火工艺对近β钛合金管材组织与力学性能的影响

研究了外径为φ10mm左右的近β钛合金管材冷轧及退火工艺。通过改变冷轧过程中的工艺参数，研究了加工变形量、减壁，减径比（Q值）对近β钛合金管材拉伸力学性能的影响。对冷轧加工管材进行680℃，1h，715℃，1h，750℃，1h，820℃，1h固溶处理后分别水淬（WQ）、空冷（AC）、炉冷（FC），研究了固溶温度、冷却速度对管材显微组织和拉伸力学性能的影响。结果表明：在小变形量下冷扎，管材塑性对形变硬化非常敏感，变形量大于35％后，马氏体转变使得合金塑性有所恢复，管材不适宜在Q值小于2的条件下加工。相变点以上固溶处理后管材屈强比不到0．6，固溶后空冷处理管材具有良好的强度和塑性匹配。     

铝青铜形变热处理工艺研究

采用气氛保护中频炉熔炼新型铝青铜合金,铸锭经热轧后立即淬火,分别进行40％、50％、60％、70％和80％的冷轧变形,然后进行中间退火(700℃×2 h)和成品退火(650℃×2h、700℃×2h、750℃×2 h)处理,并在两次退火中间分别进行20％、40％和60％的冷轧变形.通过金相显微镜(OM)和透射电镜(TEM)研究了形变热处理参数对铝青铜合金析出相和相变驱动力的影响.结果表明,提高退火温度、增加冷轧变形量,可以增大相变驱动力.合理的形变热处理参数:60％～80％冷变形+700℃×2h中间退火+20％～40％冷变形+(650～750℃)×2h成品退火,可使析出相细小且分布均匀,合金具有较高的综合性能.     

含Zr多晶Ni3Al合金在不同热处理温度下的组织与性能

研究了冷轧多晶Ni3Al-(0．2％，0．6％，1．0％，1．5％)Zr(原子分数)合金在不同热处理温度(800-1100℃)下的显微组织和力学性能，结果表明，适当的热处理温度，可使无硼Ni3Al-Zr多晶合金获得优良的室温拉伸强度和塑性，随着热处理温度的升高，不同Zr含量Ni3Al合金的再结晶体积分数增加，再结晶晶粒尺寸增大，室温拉伸强度下降．随着合金中Zr含量的增加，再结晶温度降低，再结晶晶粒尺寸减小．不同Zr含量Ni3Al合金的拉伸塑性明显依赖于热处理温度，对于低Zr(0．2％)合金，在1000℃热处理后，拉伸塑性最佳；对于中Zr(0．6％)合金，在850℃热处理后，拉伸塑性达到最大值；对于高Zr(≥1．0％)合金，拉伸塑性峰值出现在900℃热处理下，当热处理温度超过900℃，拉伸塑性显著降低。     

加工工艺对锆合金微观结构及力学性能的影响

研究了锆合金管材在不同变形量、Q值(减壁量与减径量之比)和热处理制度下显微组织、力学性能和织构状态.结果表明,大变形量(变形程度80％左右)的ZrSn合金,在510℃保温3.5 h就已发生再结晶,此后随退火温度的升高,ZrSn合金抗拉强度和屈服强度都有所下降,但下降趋势变缓;塑性有所上升,但也变化不大;为得到合理织构,管材轧制加工时Q值应远大于1.2,最好选1.8或更大.     

热处理温度对纤维相强化Cu-12Ag合金组织性能的影响

通过冷变形拉拔结合中间热处理，制备了纤维相增强的Cu-12Ag(质量分数，％)合金，采用不同温度退火研究了合金导电性能和抗拉强度随显微组织变化的关系．合金双相纤维复合组织在200℃热处理时无明显变化，强度略有降低，硬度和导电性能略有升高；当热处理温度超过400℃时，纤维组织演变为晶粒沿变形方向排列的等轴组织，合金强度及硬度显著下降，电导率显著上升．在热处理过程中，如果再结晶晶粒仅局限于原纤维组织内部生长而使得整体组织仍能保持完整的纤维形态，则合金能够表现出良好的强度与导电性匹配．     

TC2钛合金管材工艺研究

对TC2钛合金管材研制中的两辊温轧、多辊冷轧变形程度及直径壁厚变形匹配关系、温轧加热温度、中间及成品退火温度、化学成分等对管材加工成形质量、组织性能等的影响进行了研究。研究结果显示，该合金两辊温轧、多辊冷轧性能优良，在直径壁厚变形匹配合理的条件下，温轧和冷轧道次变形达40％和30％时，未产生轧制开裂等加工缺陷；温轧加热温度550℃—650℃时，Al，Mn含量控制在标准中上限，Fe，O含量适中；退火温度850℃—900℃时，轧制产品质量和各项性能指标可满足技术标准要求。     

冷轧和退火对TC4钛合金管组织和性能的影响

研究了冷轧变形及退火温度对TC4钛合金管组织和性能的影响。结果表明:变形和退火对TC4钛合金管冷轧性能影响很大,当变形为36%时,冷轧管的综合性能较好;当变形达到46%时,冷轧管出现连续月牙状缺陷和裂纹。随着退火温度的升高,管材的强度先下降后升高,塑性先升高后下降。当退火温度为850℃时,管材的强度最低,但塑性最高。最适宜管材冷轧的退火温度为850℃。此条件下,屈服强度810MPa,伸长率22%。     

冷变形及退火参数对TA16钛合金管材组织性能的影响

通过对冷加工管材的变形程度、Q值、退火温度等变形和热处理参数的实验研究,探讨TA16钛合金管材的加工变形特点和组织性能的变化规律.结果表明,该钛合金具有较强的冷变形能力,较宽的退火温度区域,可通过细化晶粒及增大Q值来提高管材的强度和塑性.     

冷变形及退火工艺对617B合金组织性能的影响

研究了冷加工变形量、退火温度和退火时间对617B合金管材组织及力学性能的影响。结果表明:随着变形量的增大,晶粒沿着最大主变形方向被拉长,形成了长条状的形变带,合金室温抗拉强度和屈服强度逐渐提高,延伸率下降;当退火温度从1080℃提高到1160℃时,随着退火温度的提高,合金的晶粒逐渐长大,抗拉强度和屈服强度降低,塑性提高,退火温度到1160℃以上继续提高温度,晶粒长大速度明显增大,强度和塑性变化不大;不同变形量下合金晶粒长大的激活能Q均远大于纯Ni的自扩散激活能,且Q值随着变形量的增加先升高后降低;合金晶粒长大指数η值随着退火温度的提高先增大后减小。     

Ti-31钛合金管材冷加工工艺研究

就Ti-31钛合金管材在两辊、多辊冷轧过程中的变形程度、中间及成品退火制度对管材加工成型质量和性能等方面的影响进行了研究。研究结果显示，该合金冷加工性能优良，冷轧道次采用50％的变形量和800℃，1h的退火制度，轧制产品的质量和各项性能指标均满足技术标准要求。     

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.     

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.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.