等离子熔积与激光切割复合直接制造CAM软件研究

针对等离子熔积制造易产生侧表面阶梯效应,导致精度和表面质量不高的问题,提出将等离子熔积和激光轮廓切割复合以改善熔积成形件表面质量的方法。开发了等离子熔积激光切割复合直接制造CAM软件,在软件中提出了一种带法向的分层切片方式,对等离子熔积、激光轮廓切割的轨迹分别进行了规划,产生相应的NC代码,并对2个单工序NC代码进行了复合,以达到等离子熔积和激光轮廓切割工艺上复合的目的。     

等离子熔积直接制造小电流熔积枪的设计

针对等离子熔积金属零件直接制造的焊道精细和持续熔积时间长的要求,设计了小电流金属等离子熔积枪.熔积枪采用了环形凸台送粉通道,钨极中心定位环,直接水冷却压缩喷嘴等改进措施.等离子熔积焊道实验结果表明,小电流条件下焊道尺寸较小,焊道平整均匀,表面光洁度好.该型小电流熔积枪适用于金属零件的等离子熔积直接制造中,同时枪体、喷嘴、送粉通道和冷却通道的特殊设计可以保证熔积枪的持续稳定工作.     

等离子熔积成形与铣削光整复合直接制造金属零件技术

针对国内外现有的金属直接快速制造技术中存在的制件表面质量不高的瓶颈问题,开发了在制造过程中将等离子熔积增材成形与铣削光整减材复合的金属零件直接快速制造方法。研究该复合制造工艺参数对熔积成形性和形状特性以及热态干铣削刀具和工艺的影响规律,找到合理的工艺条件并用其试制出金属零件原型,为改善快速原型表面质量提供了有效的途径。     

等离子激光复合成形中角度对弧柱形态和熔积层精度的影响

提出了等离子激光复合直接制造金属零件的新技术,介绍了等离子激光复合直接制造技术的基本原理。通过实验研究分析了激光束与等离子束复合角度对熔积层精度的影响规律。得到了在相同条件下,熔积层的宽度随复合角度的增加而增加的重要结论并分析了其原因。     

等离子熔积直接快速制造金属原型技术

开发了等离子熔积直接快速制造金属原型技术。该技术以等离子束为热源，根据零部件计算机三维CAD模型，数字控制熔积枪或工作台运动，粉末材料在等离子体中被加热并沉积到基板表面或熔积层的熔池中，凝固并与之熔合后形成新的熔积层，直至完整的零件制作完成。所制造零件内部无孔隙，层与层之间完全冶金结合，可以用于金属原型或难熔难加工材料零件制造、表面修复等，具有重要的应用前景。     

等离子激光复合熔积高温合金粉末的工艺研究

研究了等离子激光复合熔积高温合金粉末过程中激光对等离子弧柱形态、熔积时熔深和熔宽等的影响。实验结果表明，激光作用于等离子弧后，等离子弧弧柱的直径变小，挺度增加，稳定性增强，起弧容易，熔积层的熔深增大，熔宽减小。实验证明，这种方法直接快速成形高温合金或者难加工材料零件是可行的。     

等离子熔积/铣削复合直接制造高温合金双螺旋整体叶轮

采用等离子熔积与铣削复合制造技术，在等离子熔积成形过程中复合铣削精整，试制了难加工高温合金双螺旋整体叶轮样件，其组织性能和力学性能均高于采用传统工艺加工获得的叶轮。该技术解决了现有高能束熔积成形技术因无支撑和台阶效应造成的尺寸精度和表面质量不高的瓶颈问题，是难加工材料零件短流程、低成本、高质量无模精确制造的新的有效加工方法。     

面向等离子熔射快速制模可视化系统的三维形状检测技术

提高金属原型等离子熔积成形的精度是使该技术走向实用化的关键之一。本文将傅立叶变换轮廓法用于等离子熔积成形过程中零件的三维形状检测，来对模型的尺寸和成形过程工艺参数进行修正和补偿，提高成形精度。文章详细论述了该方法的测量原理、零件形状与所求得的相位之间的关系，建立了三雏形状测量的系统构架，最后给出了测量结果并提出了误差来源和改进措施。     

等离子熔积快速直接成形过程宏微观连成数值模拟

建立了等离子熔积快速直接成形(Plasma Deposition Manufacturing, PDM)过程多相混态场统一模型,基于蒙特卡罗法(Monte Carlo,MC)建立热影响区(Heat Affected Zone,HAZ)晶粒长大过程的数学模型。分析了不同热源功率工艺条件下熔池温度场和流场的变化规律以及特征点的温度循环曲线,进而探究了热源功率对热影响区晶粒尺寸与分布的作用机理。对AISI316合金等离子熔积过程进行了模拟,所得的计算结果与试验结果基本一致。     

一种新型复合滑板的制造工艺

介绍一种采用等离子弧熔覆方法制备的新型复合滑板的特点及其制造工艺。     

Development of a cold wire-feed additive layer manufacturing system using shaped metal deposition method

Shaped metal deposition (SMD) method would be an alternative way to traditional manufacturing methods, especially for complex featured and large scale solid parts and it is particularly used for aerospace structural components, manufacturing and repairing of die/molds and middle-sized dense parts. This method is implemented by depositing continuous cold or hot-water melted via welding arc plasma heat. This paper presents the designing, constructing, and controlling of an additive manufacturing system using TIG plus wire based Shaped metal deposition (TW-SMD) method. The aim of the current study is to design and develop an integrated system which is able to reduce time consuming and boring task of deposition process. The developed additive system is capable of producing near net shaped components of sizes not exceed 400 mm in 3 directions directly from CAD drawing. The results showed that the developed system succeeded to produce near net geometries and error-free depositions for various features of SS308LSi components. Additionally, workshop tests have been conducted in order to verify the capability and reliability of the developed AM system.     

Self-Adaptive Control System for Additive Manufacturing Using Double Electrode Micro Plasma Arc Welding

Wire arc additive manufacturing(WAAM)has been investigated to deposit large-scale metal parts due to its high deposition efficiency and low material cost.However,in the process of automatically manufacturing the high-quality metal parts by WAAM,several problems about the heat build-up,the deposit-path optimization,and the stability of the process parameters need to be well addressed.To overcome these issues,a new WAAM method based on the double electrode micro plasma arc welding(DE-MPAW)was designed.The circuit principles of different metal-transfer models in the DE-MPAW deposition process were analyzed theoretically.The effects between the parameters,wire feed rate and torch stand-off distance,in the process of WAAM were investigated experimentally.In addition,a real-time DE-MPAW control system was developed to optimize and stabilize the deposition process by self-adaptively changing the wire feed rate and torch stand-off distance.Finally,a series of tests were performed to evaluate the con-trol system's performance.The results show that the capability against interferences in the process of WAAM has been enhanced by this self-adaptive adjustment system.Further,the deposition paths about the metal part's layer heights in WAAM are simplified.Finally,the appearance of the WAAM-deposited metal layers is also improved with the use of the control system.     

Decomposition of PFC gas using a water jet plasma

Perfluorocarbons (PFCs) have been adopted for plasma etching and chemical vapor deposition process in semiconductor manufacturing. Among the other exhaust gases, PFCs have longer residual time in air and higher global warming potential. To remove PFCs, water jet gliding arc plasma was designed and prepared. Water jet gliding arc plasma has received the attention as a PFCs decomposition technique due to the formation of OH radical and wide range of plasma.     

Material bead deposition with 2 + 2 ½ multi-axis machining process planning strategies with virtual verification for extruded geometry

Process planning for hybrid manufacturing, where additive operations can be interlaced with machining operations, is in its infancy. New plastic- and metal-based hybrid manufacturing systems are being developed that integrate both additive manufacturing (AM) and subtractive (machining) operations. This introduces new process planning challenges. The focus of this research is to explore process planning solution approaches when using a hybrid manufacturing approach. Concepts such as localized AM build ups, adding stock to a CAD model or section for subsequent removal, and machining an AM stock model are investigated and illustrated using virtual simulations. A case study using a hybrid laser cladding process is used to demonstrate the opportunities associated with a hybrid solution. However, unlike machining, the process characteristics from system to system vary greatly. These are portrayed via a high power, high material deposition feed rate laser cladding system. There are unique challenges associated with AM processes and hybrid manufacturing. New tools and design rules need to be developed for this manufacturing solution to reach its potential.     

形状沉积制造及其应用

文章在分析了常规的快速原型制造所存在的缺点后，详细地介绍了形状沉积制造区别于快速原型制造过程中单纯地添加材料的过程——添加／去除零件材料方法，正是由于这一差别使得该方法制造的零件精度不受分层厚度的影响，并且可以采用多种材料制造零件。介绍了形状沉积法的具体工艺过程、可采用的材料沉积工艺方法、沉积制造的设备构成、分层技术、特点及基于形状沉积制造的新方法——模具形状沉积制造，最后介绍了形状沉积制造在功能零件、模具及预装配机构快速制造中的应用实例。     

Development of newly installed processes

This paper describes the use of statistical methods as advocated by Taguchi to characterise and optimise a silicon nitride deposition process on a newly installed plasma deposition kit. By using orthogonal experimental design and analysis techniques, these methods allow a multiresponse process to be optimised with only a small number of experiments. Assessment of these experiments differs from conventional methods in that it is of first importance to minimise the variation in response. This then gives a process which is insensitive to the effects of uncontrollable factors. Using these techniques, yields of at least 99% have been obtained for the process studied. Although this paper describes an application of the Taguchi technique to a particular process, the method is widely applicable to many other activities within the context of advanced manufacturing technology.     

增/减材柔性制造及加工系统构成形式

将柔性制造的思想引入到增/减材制造中,形成增/减材柔性制造工艺。阐述了该工艺的内涵及加工范围,确立了增/减材柔性制造工艺流程,描述了各组成工序的特点,详细阐述了增/减材柔性制造中材料沉积、材料去除两工序内部及其之间的多种柔性加工方式。在此基础上,确立了增/减材柔性制造系统的设备构成及其相互关系,给出了加工设备的总体布局。为进一步研究该工艺的加工序列规划及各种构成设备具体结构形式等方面打下基础。