Rapid Manufacturing of Metal Parts

As a key technology of rapid prototyping and manufacturing (RP&M), rapid manufacturing of metal parts is a target of RP&M. Introducing selective laser sintering (SLS), an important branch of RP&M, this paper gives a new method oriented on low power SLS system to fabricate metal parts. With this kind of technology, the mixture of metal and polymer powder is sintered first to get green part, then, after debinding and metal infiltration, dense parts are gotten. In the end, influencing factors of this technology are analyzed. At the same time, some applications are given.

Research on Application Technology Oriented Rapid Response Manufacturing in the Distributed Network Environment

A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environments, that is, how to take advantage of the Intranet and Internet, combine the numerous manufacturing resources spread around the region, the country and even the globe is the key to the agile design, manufacturing and the buildup of comprehensively competitive power, at the same time, is also an important research direction in the field of advanced manufacturing technology. Rapid response manufacturing in the distributed network environment is a newly manufactory pattern that can be used to implement the conception of agile design and manufacturing, but there are some new problems coming with it, which will directly influence the enterprise’s ability of rapid response in the distributed network manufacturing pattern and lead to the failure of the league and the lost of the given orders. In this paper, we establish some approaches to solve these problems in product development process. The paper then presents the research on key application technologies and solutions includes: network safety strategy which guarantees data transferring among the leaguer members, production data management based on Web/DOT (Distributed Object Technology) and XML criteria which guarantees data exchange in structure-variance characteristic environments, the network platform which provides the conversion service of different types of CAD files each other. All of these solutions are aim for technology problems existing in the distributed network environments and among the league members. Finally, the paper takes one project, that is, the establishment of the online application service system for Shanghai Advance Manufacturing Technology Research Center as a good instance.

Rapid manufacturing of SiC molds with micro-sized holes using abrasive water jet

Silicon carbide (SiC) is highly wear resistant with good mechanical properties, including high temperature strength, excellent chemical resistance, and high thermal conductivity and thermal shock resistance. SiC molds, which can be produced with diverse microstructural features, are now widely used in glass molding owing to their excellent characteristics, and also have potential applicability in IT industries. SiC molds are traditionally fabricated by silicon micromachining or dicing. The fabrication cost of silicon micromachining is very high, however, because several expensive masks are needed. Furthermore, the fabrication time is very long. Meanwhile, it is difficult to make micro-patterned molds with arbitrary shapes using dicing saws. Abrasive water jet (AWJ) is widely applied to cut and drill very brittle, soft and fibrous materials. It offers high energy density, the absence of a heat affected zone(HAZ), high performance, and an environment friendly process. In spite of these advantages, micro-hole drilling via conventional AWJ processing suffers from notable shortcomings. We proposed a new abrasive supplying method of AWJ. The proposed method reduces frosting phenomena, and provides micro-machining of AWJ. The characteristics of a hole machined was investigated by the proposed AWJ process according to the ratio of water and abrasives. With the optimal experimental conditions, 3×3 array SiC molds with the diameter of 700 μm and depth of 900 μm were successfully manufactured.

A review of additive manufacturing technology and its application to foundry in China

The application of additive manufacturing technology is one of the main approaches to achieving the rapid casting.Additive manufacturing technology can directly prepare casting molds(cores)with no need of patterns,and quickly cast complex castings.The combination of additive manufacturing and traditional casting technology can break the constraint of traditional casting technology,improve casting flexibility,and ameliorate the working environment.Besides,additive manufacturing promotes the realization of"free casting",greatly simplifying the processing procedures and shortening the manufacturing cycle.This paper summarizes the basic principle of additive manufacturing technology and its development situation domestically and overseas,mainly focusing on the development status of several main additive manufacturing technologies applicable to the foundry field,including three-dimensional printing,selective laser sintering,stereolithography,layered extrusion forming,etc.Finally,the future development trend of additive manufacturing technology in the foundry field is prospected.

Localized electrodeposition micro additive manufacturing of pure copper microstructures

The fabrication of pure copper microstructures with submicron resolution has found a host of applications,such as 5G communications and highly sensitive detection.The tiny and complex features of these structures can enhance device performance during high-frequency operation.However,manufacturing pure copper microstructures remain challenging.In this paper,we present localized electrochemical deposition micro additive manufacturing(LECD-μAM).This method combines localized electrochemical deposition(LECD)and closed-loop control of atomic force servo technology,which can effectively print helical springs and hollow tubes.We further demonstrate an overall model based on pulsed microfluidics from a hollow cantilever LECD process and closed-loop control of an atomic force servo.The printing state of the micro-helical springs can be assessed by simultaneously detecting the Z-axis displacement and the deflection of the atomic force probe cantilever.The results showed that it took 361 s to print a helical spring with a wire length of 320.11μm at a deposition rate of 0.887μm s^(-1),which can be changed on the fly by simply tuning the extrusion pressure and the applied voltage.Moreover,the in situ nanoindenter was used to measure the compressive mechanical properties of the helical spring.The shear modulus of the helical spring material was about 60.8 GPa,much higher than that of bulk copper(~44.2 GPa).Additionally,the microscopic morphology and chemical composition of the spring were characterized.These results delineate a new way of fabricating terahertz transmitter components and micro-helical antennas with LECD-μAM technology.

Resources publication and discovery in manufacturing grid

In the manufacturing grid＇s architecture, Resources Management System （RMS） is the central component responsible for disseminating resource information across the grid, accepting requests for resources, discovering and scheduling the suitable resources that match the requests for the global grid resource, and executing the requests on scheduled resources. In order to resolve the problem of resources publication and discovery in Manufacturing Grid （MGrid）, the classification of manufacturing resources is first researched after which the resources encapsulation class modes are put forward. Then, a scalable two-level resource management architecture is constructed on the model, which includes root nodes, domain nodes and leaf nodes. And then an RIMS is proposed, and the resources publication and discovery mechanism are detailedly described. At last, an application prototype is developed to show the validity and the practicability of the proved theory and method.

On Application of Metal Additive Manufacturing

Metal additive manufacturing is an important branch of AM, which provides an effective method for the innovative manufacturing of metal parts. Here, flow chart and main techniques of metal additive manufacturing are firstly described according to the used material types. Many application examples of metal additive manufacturing are then listed based on application value. The summary is finally given to point development direction of metal additive manufacturing in the future. Additive manufacturing, which is an effective supplement to traditional methods, will play an important role in intelligent and digital manufacturing.

New development on additive manufacturing technology and its applications

Additive manufacturing technology has been developed in Xi＇ an Jiaotong University for almost 20 years. Up to now~ it is still attracting the attentions of the researchers or manufacturers all over the world. Some in- novative processes and frontier application research are all being conducted here to catch up with the new develop- ment of this technology. In the paper, newly developed processes, such as ultraviolet-light emitting diode （UV- LED） stereolithography, ceramic stereolithography, and direct metal forming, were described. Some results of the frontier application researches, such as indirect fabrication of ceramic casting mould, wind-tunnel-testing models, photonic crystals and metamatcrials, were also briefly reviewed.

Rapid Sample Product Trial Manufacture Technique for Developing Water Meter New Products

This paper advances the viewpoints and methods of the rapid sample product trial manufacture technique for developing water meter new products by CAD and simulation, computer virtual assembling and optimizing, rapid machining process and measurement etc. as the design and sample product trial manufacture process of water meter new products are long in product development period, and low in product development efficiency in the present time.

The Impact of 3D Printing Technology to the Nigerian Manufacturing GDP

3D printing can spur manufacturing rebirth in Nigeria and the World in general. There are many areas where 3D printing is creating significant change, particularly in designing and prototyping of new products, in the arts, and in visualizing abstract concepts. This is a step change from conventional manufacturing processes to rapid prototyping and layer manufacturing. This report has defined rapid prototyping, rapid manufacturing and the current technologies available to fabricate 3D components. In addition to this, it provides a brief overview of the current contributions of the Edo University Iyamho (EUI) in collaboration with the Federal University of Petroleum Resources, to sustain manufacturing research initiatives towards the development of locally fabricated 3D printer and the possible future Additive Manufacturing in Nigeria. It is anticipated that this work will benefit the Nigerian academic, research institutes, industries, thus, enhance the GDP contribution of the manufacturing sector in Nigeria.

Precise Control of Temperature Rising Speed of Wafer during Rapid Thermal Processing

In rapid thermal processing of a semiconductor wafer, it is important to keep a given temperature rising speed of the wafer during the temperature rising process. We made an experimental apparatus to measure the temperature rising speed of a ceramic ball of 2 mm in diameter heated with four halogen lamp heaters. The heating rate of the halogen lamp heaters was controlled by computer to keep a given temperature rising speed of 50 ℃/s with a controlling time interval of 0.1 s. We examined the effect of various heating control methods on the error of the temperature rising speed of the ceramic ball. We found that a combined method of control with prepared correlation and PID （proportional integral derivative） control is a good method to decrease the error of the temperature rising speed. The average error of the temperature rising speed is 0.5 ℃/s, and the repetition error is almost zero for the temperature rising speed of 50 ℃/s from 330 ℃ to 370 ℃. We also measured the effects of artificial control delay time and measuring error of the monitoring temperature on the error of the temperature rising speed.

Rapid manufacture of Ni-based superalloy components by three-dimensional printing

The challenge to rapid manufacturing high performance metal components is how to consolidate the uncompressed powder preforms to full or near full density without shape distortion. A new approach developed by ProMetal was proposed, in which a bimodal powder, typically a coarse prealloyed powder blended with a fine metal powder was used to build green preforms by three-dimensional printing and then sintered at a temperature above the solidus temperature of the coarse prealloyed powder and below the melting temperature of the fine powder particles or the solidus temperature if the fine powder is a prealloyed powder as well. This approach was successfully applied to sinter Ni-based superalloy 718 preforms, which were built through three dimensional printing into near full density.

Direct Digital Manufacturing Industry Ascendant

The paper introduces the origin of the word of Direct Digital Manufacturing and other forms of address, and the working principles of Direct Digital Manufacturing technology and major types of the technology, hard- ware and software development, use of materials, applications, market growth and its development prospects. Focused presentations of Direct Digital Manufacturing （additive manufacturing） compared to traditional mechani- cal manufacturing industry in the use of prices, processing speed, reliability and cost advantages and characteris- tics. Particularly the significant challenges and competitiveness of Direct Digital Manufacturing technology in the processing of any complexity created directly the number of objects, internal structure and channel function, as well as the shape of the chassis components and structure of the matching and optimization.

快速重组制造系统(RRMS)——新一代制造系统的原理及应用

为提高制造系统对市场和产品变化的快速适应能力 ,探求了制造系统可重组的理论、方法及其应用技术。提出了快速重组制造系统 (RRMS)的基本构架及其特征 ;研究其科学基础 ,得出了RRMS的随机模型及其组态的优化方法 ,发展了用于布局规划优化的拟阵算法 ,提出了系统可诊断性原理并建立了经济可承受性的理论框架 ;初步研究了RRMS的使能技术 ,建立了规划与设计、快速集成、快速运行、快速拆卸与重复利用 4个子系统。研制了组成RRMS的组态制造单元 (CMC) ,研发的基于组态制造单元组成的新颖的阵列式布局的RRMS在汽车和计算机零件生产线上得到成功的应用 。

采用遗传算法的RMS设备布局设计及仿真

根据可重构制造系统车间设备布局的最小物流费用原则,建立车间的单行和多行设备布局的数学模型,针对设备布局属于NP完全问题,提出利用MATLAB遗传算法工具箱实现一个基本的设备布局模型的求解,降低了遗传算法对设备布局问题的求解难度。最后,给出一个六台设备的车间布局实例,采用Delmia/QUEST三维可视化仿真软件对求解的布局结果建立仿真模型,并进行仿真结果分析,为设备布局的改进提供决策依据。通过重建仿真模型,能够很好地解决设备布局问题。

基于RMS关键特征偏好排序的重构方案评估方法

针对如何构建反映可重构制造系统本质特性的评估指标定量模型,以及某一重构方案相对其他方案优势和劣势都绝对明显情况下如何实现多方案优选的问题,提出一种基于RMS关键特征偏好排序的重构方案评估方法.在综合考虑可重构机床组件调整、制造单元调整基础上,建立衡量RMS可缩放性、可转换性、可诊断性、模块化、可集成性和定制化等特征的量化模型,以此为基础形成重构方案的评估指标,并采用层次分析法分配评估指标权重.评估过程中,先从局部采用部分偏好排序评估方法分别对方案的优势和劣势进行评估,然后从整体上通过完全偏好排序评估方法对重构方案的净优势进行评估,最终得出重构方案的综合评估结果.并以某研究所RMS车间为例,阐述了该方法的实施过程并验证其有效性和实用性.

仿真环境下RMS设施布局分析研究

可重构制造系统(RMS)设施布局问题是一个重要而复杂的研究课题,对制造系统的性能有很大的影响。首先在综合考虑系统复杂性特点的基础上,构建了相应的成本数学模型。然后基于产品种类、生产批量和订货提前期这三个方面的市场需求特征,对RMS布局重构策略进行分析,并构建了仿真框架和仿真流程。最后通过案例分析,验证了该分析方法的可行性和有效性,为RMS布局重构提供了决策依据。

面向RMS的公理化设计分解耦合性研究

首先介绍了可重构制造系统和公理化设计的基本概念,然后对可重构制造系统进行了二级分解,选取了其中非耦合情况下和准耦合情况下的案例,进行了可重构制造系统公理化设计,提出了X是算子的概念,并赋予了,新的概念。创新的利用公理化设计的方法对可重构制造系统进行相应的拆分与重组:根据市场需求,将整个制造系统拆分成具有部分功能组合的制造系统;将各个功能组合,组成整个制造系统。这对于提高制造系统的利用率,快速应对市场需求具有十分重要的意义。

Deformation behaviors of as-built and hot isostatically pressed Ti-6Al-4V alloys fabricated via electron beam rapid manufacturing

The deformation behavior of as-built and hot isostatically pressed(HIP)Ti-6Al-4V alloys fabricated using electron beam rapid manufacturing(EBRM)were investigated in this work.The deformation characteristics were characterized using a laser scanning confocal microscope and electron back-scattered diffraction(EBSD).In the as-built sample,prismatic slip was the main mode of deformation,as well as a small amount of basal slip and cross-slip.Some planar slip lines with large length scales were observed across severalαlamellae.After hot isostatical pressing,prismatic and basal slip were the main mode of deformation,accompanied by abundant cross-slip and multiple slip,and most of the slip lines were blocked within an a lamellae.These differences in deformation behavior were associated with the coarsening of a laths and the more retained p phase after HIP compared to the as-built alloy.More cross-slip and multiple slip can lead to superior elongation-to-failure and a greater strain hardening effect in the HIP alloy compared to the as-built sample.

Rapid casting technology based on selective laser sintering

Selective laser sintering(SLS),as a kind of additive manufacturing technology,which uses a laser beam to scan and heat powder material layer by layer to form parts(models),is widely used in the field of casting,mainly for preparing casting coated sand cores,investment casting patterns,etc.The SLS technique facilitates rapid casting and shortens the casting production periods by eliminating mold preparation.In this study,we reached conclusions for the basic principles and characteristics of SLS methods,and focused on the research status,key technology and development trend of SLS in the fields of forming coated sand-casting molds and investment casting patterns.