The present status of dental titanium casting

Experimentation in all aspects of titanium casting at universities and industries throughout the world for the last 20 years has made titanium and titanium-alloy casting nearly feasible for fabricating sound cast dental prostheses, including crowns, inlays, and partial and complete dentures. Titanium casting in dentistry has now almost reached the stage where it can seriously be considered as a new method to compete with dental casting using conventional noble and base-metal alloys. More than anything else, the strength of titanium’s appeal lies in its excellent biocompatibility, coupled with its comparatively low price and abundant supply. Research efforts to overcome some problems associated with this method, including studies on the development of new titanium alloys suitable for dental use, will continue at many research sites internationally. Toru Okabe earned his Ph.D. in metallurgical and materials engineering at the University of Florida in 1969. He is currently professor and chair of biomaterials science at Baylor College of Dentistry. Dr. Okabe is a member of TMS. Chikahiro Ohkubo earned his Ph.D. in removable prosthodontics and his D.M.D. in dentistry at Tsurumi University in 1989 and 1985, respectively. He is currently an instructor at the School of Dental Medicine at Tsurumi University in Yokohama, Japan. Ikuya Watanabe earned his Ph.D. in dental science at Nagasaki University in 1995. He is currently working at Nagasaki University, Japan. Osamu Okuno earned his Ph.D. in engineering at Waseda University in 1976. He is currently a professor and chair in the Department of Dental Materials Science, School of Dentistry, Tohoku University, Japan. Yukyo Takada earned his Ph.D. in engineering at Waseda University in 1991. He is currently assistant professor in the Department of Dental Materials Science, School of Dentistry, Tohoku University, Japan.     

New progresses of Chinese art casting

The Chinese art casting with 5 000 years history has been rapidly developed in recent ten years. This benefits from the great development of Chinese economy, the large-scale urban construction and transformation, the increasing demands for the cultural work of art, the loose religious environment and the expanding international market.     

Contemporary art casting’s education in Guangdong

Based on the practical experience of establishing three art casting laboratories in three different colleges of Guangdong,this paper focuses on the development of contemporary art casting’s education.By analyzing the reason for the shortage of professionals nowadays and the characteristics of modern foundry industry in the Pearl River Delta,the authors try to find out what kind of knowledge structures a modern foundry industry professional should have.Then,from the viewpoint of education,the authors introduce how to combine the art casting laboratory and the creative art casting course as a new teaching pattern,on the one hand,to attract more students to study casting technology,on the other hand,to train them to be qualified professionals for the modern foundry industry.     

Application of digital pattern-less molding technology to produce art casting

Compared with the conventional casting process, digital pattern-less casting technology has many advantages such as good machining accuracy, a short processing cycle, and low production cost. It is a new rapid manufacturing technology for castings, integrated with CAD/CAM, casting, CNC machining and many other advanced technologies. With this digital casting technology, no pattern is needed for making molds; it is precise, flexible, and green. Usually, art castings have complex structures and are made in small batches or even made in a single-piece, especially for large-sized art castings. So it has the shortcomings of high cost, low efficiency and long time for making a pattern to produce art castings with the conventional casting processes. However, the digital pattern-less casting technology can be applied to fabricate art castings, since it can greatly shorten the manufacturing cycle and lower the production cost, thus having a very good prospect. In this study, based on the digital pattern-less casting technology, a plaque casting with artistic Chinese characters （a Chinese poem） was designed and manufactured, and the production process was demonstrated in detail.     

Development of electroslag metallurgy and casting in China

The electroslag metallurgy has been developed since 1958. At present, all special steel plants have constructed electroslag metallurgical workshops. There are 86 Electroslag Remetting (ESR) furnaces in these steel plants with annual capacity of 100 000 tons. The products by ESR include 243 designations of steel and superalloy. The Chinese metallurgists have made significant achievements in the type and structure of electroslag remelting furnaces, eletroslag remelting technology, shaped castings by Electroslag Remelting Casting (ESRC), the manufacture of large-size ingots by ESR and the study of ESR mechanism. These achievements have already been recognized by foreign metallurgists.     

板坯连铸机双浇技术在我国的应用

本文概述板坯双浇技术的工艺及设备特征，报道两个工厂初步的生产情况，展望技术的应用前景。     

连铸过程中电磁流体力学的数值模拟现状及发展趋势

对连铸过程中电磁流体力学的数值模拟的研究现状进行了综合评述。介绍了一种应用于连铸过程中的低频电磁流体力学数值模拟的新方法,并给出了其在圆坯旋转搅拌、CSP薄板坯电磁制动和板坯二冷辊式行波搅拌中的应用实例。该方法特点是分别建立电磁场模型和流场模型,并采用磁感应方程实现电磁场和流场模型之间的耦合。结果表明,目前的方法可较为准确地描述连铸过程中的电磁场分布和电磁流体力学特点,并能够对电磁搅拌参数和连铸工艺过程进行优化。最后,提出了连铸过程中电磁流体力学数值模拟技术的未来发展趋势。     

Research progress on squeeze casting in China

Squeeze casting is a technology with short route,high efficiency and precise forming,possessing features of casting and plastic processing.It is widely used to produce high performance metallic structural parts.As energy conservation and environmental protection concerns have risen,lightweight and high performance metal parts are urgently needed,which accelerated the development of squeeze casting technology over the past two decades in China.In this paper,research progress on squeeze casting alloys,typical parts manufacturing and development of squeeze casting equipment in China are introduced.The future trend and development priorities of squeeze casting are discussed.     

Twin-roll strip casting of magnesium alloys in China

The development status of twin-roll strip casting for magnesium alloys in China was summarized as well as the new progress when several kinds of twin-roll strip casting technologies were developed and used.Horizontal twin-roll casting (HTRC) of magnesium alloys has attracted much attention and has been industrialized in China.Vertical twin roll casting(VTRC) of the magnesium alloys can reach a speed of higher than 30 m/min and its research and development are just beginning and exhibit exciting potential...     

我国薄板坯连铸连轧技术发展概况

介绍了我国连铸连轧生产线发展概况和生产技术、品种开发的进展、生产工艺流程的优化,工厂与大专院校的合作等.     

Development and application of titanium alloy casting technology in China

1 Introduction Titanium, which is named as the third metal after iron and aluminum, is an idea structure alloy for aerospace because of its unique properties such as high specific strength and high corrosion resistance [1-4].Using titanium alloy products, the weight of aerocraft can be greatly lightened and the performance of flight can be dramatically improved. In recent years titanium alloys are not only used widely in aerocraft but also in other industries in the world [6-9]. Due to its hig…     

Postage stamps: A convergence of metallurgy, art, and history

Postage stamps have been used around the world to commemorate, in miniature, significant events and people, including those of importance in the history of metals and mineral production. From the presence of gold artifacts in an ancient Egyptian tomb to the role of uranium in nuclear power, stamps have captured the evolution of metallurgical processes. This article highlights some of those stamps.     

我国汽车模具出口现状与转型思考

结合我国汽车模具制造业近年的发展历程及一汽模具制造有限公司的发展升级策略,参考相关统计数据,介绍了国内模具产业总体情况,分析了我国模具进出口情况,论述了我国高档汽车模具出口转型的重要性及必要性。     

我国旋压技术的现状与发展

从旋压设备和旋压工艺两方面对我国旋压技术近几年的发展状况进行了详尽的、客观的分析.我国的旋压技术近十年来有了很大的发展,但同时也存在着一系列问题,和国际先进水平还有一定差距.随着我国的旋压工艺和旋压设备必将迈上一个更高的台阶,迎来一个更大的发展.     

我国大型铸锻件应坚持国产化之路

近年来,我国大型铸锻件行业技术水平有了较高的提升,但是整体技术水平还相当于上世纪90年代的国际水平,比较落后,面对我国对大量形状复杂、技术含量高、材料性能特殊的大型铸锻件日益迫切的需求,我国大型铸锻件行业应依托装备制造业调整振兴规划,坚持国产化道路,分享我国工业发展的巨大成果。     

国内连铸机自动化系统的发展现状及展望

近年来,我国连铸自动化技术发展迅猛,作者将从连铸机自动化系统的典型配置、目前所涵盖的控制技术以及在工艺控制系统方面取得的突出性成果(数学模型)等方面介绍连铸自动化系统的发展现状,并对连铸机自动化的发展趋势提出一些展望.     

我国方坯高效连铸技术应用和发展的一些问题

连铸技术在我国的应用过程中还存在很多问题，对高效连铸关键技术如高效结晶器的设计、二冷区优化配水和电磁搅拌等还缺乏足够的认识，在连铸高效化的改造过程中造成一些质量。本文讨论方士连铸高效化中这些关键技术的应用。     

中国焊接钢桥的发展

中国在20世纪60年代开始栓焊铜桥的建设,但焊接铜桥的大发展却是在20世纪90年代以后.简要介绍了焊接钢桥在中国发展的几个阶段、发展水平以及若干技术进展,包括桥梁钢的开发及其焊接材料的优化、焊缝强韧性的控制标准问题.     

The tilt casting process

Tilt casting is a process with the unique feature that, in principle, liquid metal can be transferred into a mould by simple mechanical means under the action of gravity, but without surface turbulence. It therefore has the potential to produce very high quality castings. Even so, the process is not often optimised in the industrial environment. This investigation represents an attempt to investigate some fundamental problems associated with the process.

A computer controlled, programmable roll-over casting wheel with a diameter of 1 m was used to produce sand castings in an Al-4.5% Cu alloy. The filling of the mould was studied using realtime X-ray radiography. Real-time X-ray radiography revealed that the molten metal could exhibit tranquil, turbulent or chaotic flow into the mould during tilt casting, depending on (i) the angle of tilt of the mould at the start of casting, and (ii) the tilting speed. Essentially horizontal transfer of the melt could achieve tranquil filling of the mould with minimum surface turbulence by a tilt starting position above the horizontal. The tensile properties of castings made using various starting conditions and rotation rates were measured and the results analysed using Weibull statistics to quantify reliability. Results are summarised on a map of the various operating regimes for tilt casting. An operational window for the production of reliable castings has been defined for the first time.