梯度聚晶金刚石复合材料的开发

应用粉末层铺法制备梯度聚晶金刚石复合片材料，并通过SEM、XRD、显微硬度等对该材料进行组织与性能分析。结果表明，在以钴作粘结剂的聚晶金刚石层中金刚石相实现了D-D结合，通过梯度过渡层与硬质合金基体结合既保证了聚晶金刚石的硬度，又改善了界面的结合状况，从而提高了聚晶金刚石复合片的性能和使用寿命。     

纯相PCBN的研究进展

立方氮化硼以其优异的特性广泛应用于现代制造加工领域。随着制造要求的不断提高,对氮化硼的性能提出更高的要求,世界各国相继开发研究出纯相立方氮化硼的合成技术。本文对国内外纯相聚晶立方氮化硼的烧结、性能等进行了综述,并分析了各种纯相烧结方法。最后对纯相聚晶氮化硼的发展方向进行了展望。      

放电等离子烧结制备立方氮化硼聚晶

采用放电等离子烧结工艺(spark plasma sintering,简称SPS)在氮气气氛中制备了以Si3N4-AlN-Al2O3-Y2O3系为基的立方氮化硼聚晶(polycrystalline cubic boron nitride,简称PcBN).烧结工艺参数为:加热速率300 ℃/min,初始压力30 MPa,保温时间5 min,烧结温度分别为1250 ℃、1350 ℃和1450 ℃.利用X射线衍射分析(XRD)和扫描电子显微镜(SEM)对样品的物相构成和试样新鲜断口的微观形貌进行了分析和观察,同时利用显微硬度测试仪测试了样品的显微硬度.实验结果表明,Si3N4-AlN-Al2O3-Y2O3-BN系聚晶材料可以在非常短的时间内致密化,样品的相对密度可达95%以上.采用SPS快速烧结工艺,样品中的超硬磨料cBN依然保持立方结构.随着烧结温度的提高,样品的硬度不断增加,PcBN的显微硬度为28～48 GPa.结合剂组份可与立方氮化硼牢固地结合在一起.放电等离子烧结工艺可成为制备PcBN刀具材料的一种新的制备方法.     

无黏结相PCD和PCBN材料研究进展

无黏结相PCD和PCBN具有良好的高温性能,特别是拥有纳米晶粒或纳米结构的PCD和PCBN的性能甚至高于单晶体的性能。对无黏结相聚晶立方氮化硼（PCBN）和聚晶金刚石（PCD）材料的合成方法、烧结机理及其性能进行了详细概述。在高于7 GPa和1800℃下,能烧结出致密的无黏结相PCD和PCBN材料,但不同原材料粉末和微量触媒或掺杂会对超高压高温（HPHT）烧结条件和机理产生较大的影响。基于HPHT方法的制备条件较苛刻,PVD和CVD是比较有前途的制备PCD的方法,但用于制备PCBN还需要解决许多技术问题。      

PCBN切削刀具的性能及合理使用

本文介绍了聚晶立方氮化硼切削刀具的性能，进一步阐述了聚晶立方氮化硼切削刀具的适用范围及其相关的应用技术。     

Ti(C,N)系结合剂PCBN复合片制备及性能研究

以Ti(C,N)为主结合剂,添加不同物质制备高韧性、高耐磨性刀具用PCBN复合片,探讨Ti(C,N)系结合剂聚晶立方氮化硼(PCBN)复合片的显微硬度、磨耗比、抗冲击韧性与不同添加物的关系,同时采用X射线衍射仪,扫描电镜等仪器设备对PCBN复合片进行物相和微观组织结构分析。实验结果表明:WC、Al2O3、Y2O3、表面镀镍SiC晶须等物质的添加显著提高了复合片的综合性能,AlN的加入反而降低了复合片的耐磨性和抗冲击性能。     

人造金刚石聚晶磨耗比与磁性关系的研究

采用不同的烧结工艺在高温高压下烧结出三批金刚石聚晶，然后采用WCF-2多用磁性分析仪和JS71-A型磨耗比测定仪对人造金刚石聚晶的磁性与磨耗比进行测量，并且分析了不同的烧结工艺和粘结剂和对聚晶磁性和磨耗比的影响。结果表明：人造金刚石聚晶的磨耗比与磁性之间存在着一定的关系，即一定的烧结条件下聚晶的磁性愈强反而它的磨耗比愈小。这样通过测量人造金刚石聚晶的磁化率可以对其进行初步分类，可以避免传统的有损检测，是一种可行的检测方法。     

国外立方氮化硼研制技术(Ⅺ)

十一、立方氮化硼聚晶的制造自动化加工技术对切削效率、精度提出了新的要求。要切削高强度、高硬度、耐高温、耐腐蚀的难加工材料,刀具必须有良好的物理、化学和机械性能。要提高加工效率和精度,刀具必须有高的耐用度,而立方氮化硼聚晶(PCBN)作为刀具材料完全能满足这些要求。因此各国研究者对立方氮化硼聚晶的制造方法及其有关问题进行了大量研究工作,本文拟将其中的一些问题做一阐述。     

超硬涂层切割工具

根据ISO513国际标准,超硬切割工具材料可分为立方氮化硼烧结体（PCBN）和金刚石聚晶（PCD）。     

XRD方法在聚晶金刚石复合片界面应力表征中应用的研究

借助XRD方法对不同生产工艺、无齿、有齿型硬质合金基底制备的PDC制品进行了研究。表明：聚晶金刚石复合片在聚晶金刚石层内存在着宏观应力和微观应力；聚晶金刚石复合片表面应力大小可以反映聚晶金刚石层的应力存在状况；聚晶金刚石复合片残余应力的大小与XRD图谱的斜率成正比，因此XRD方法可以用于聚晶金刚石复合片应力的表征。     

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.