Process Control and Development for Ultrasonic Additive Manufacturing with Embedded Fibers
Process Control and Development for Ultrasonic Additive Manufacturing with Embedded Fibers
复制标题
嵌入式纤维超声波增材制造的过程控制和开发
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
A. Hehr
中科院分区：
文献类型：
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作者：
A. Hehr
超声波增材制造（UAM）是一种最新的增材制造技术，它结合了超声波金属焊接，CNC加工和机械化箔层，以创建大型无间隙近净形金属零件。该工艺由于其低的成形温度、连接不同金属的能力以及创建单独使用传统减材工艺不可能实现的复杂设计特征的能力，最近引起了人们的广泛关注。这些工艺属性使结构和组件以前所未有的方式实现轻量化。然而，由于缺乏质量跟踪和对过程的科学理解不足，UAM目前仅限于利基领域。因此，本论文的工作重点是提高组件质量跟踪和过程的理解，通过使用平均电功率输入到焊机。此外，使用UAM嵌入纤维到金属的理解和应用空间进行了调查，特别是侧重于NiTi形状记忆合金纤维。最近，9千瓦UAM工艺变量已经验相关的粘结强度为铝6061-H18建立使用统计设计的实验研究。研究中评估的工艺变量为焊机振幅、法向力、焊机行进速度和基板温度。在统计研究中确定的UAM过程变量和属性关系启发了基于能量的模型和控制方法的开发，以改进UAM构建。特别地，已经发现从超声换能器经验测量的输入平均电焊功率与构造的所得焊接微观结构和机械强度相关。为了理解焊机中电能到机械能的转换，利用经典的电声学理论和超声焊极的现场测量，建立了线性时不变（LTI）模型
Ultrasonic additive manufacturing (UAM) is a recent additive manufacturing technology which combines ultrasonic metal welding, CNC machining, and mechanized foil layering to create large gapless near net-shape metallic parts. The process has been attracting much attention lately due to its low formation temperature, the capability to join dissimilar metals, and the ability to create complex design features not possible with traditional subtractive processes alone. These process attributes enable light-weighting of structures and components in an unprecedented way. However, UAM is currently limited to niche areas due to the lack of quality tracking and inadequate scientific understanding of the process. As a result, this thesis work is focused on improving both component quality tracking and process understanding through the use of average electrical power input to the welder. Additionally, the understanding and application space of embedding fibers into metals using UAM is investigated, with particular focus on NiTi shape memory alloy fibers. Recently, 9 kW UAM process variables have been empirically correlated to bond strength for Al 6061-H18 builds using a statistical design of experiments study. The process variables evaluated in the study were welder amplitude, normal force, welder travel speed, and baseplate temperature. The UAM process variables and property relationships identified in the statistical study inspired the development of an energy based model and control approach for improved UAM builds. In particular, input average electrical weld power, which has been empirically measured from the ultrasonic transducers, has been found to correlate with resultant weld microstructure and mechanical strength of builds. To understand the conversion of electrical to mechanical energy in the welder, a linear time invariant (LTI) model was developed using classic electroacoustics theory and in-situ measurements of sonotrode