Statnikov Efim Sh, Korolkov Oleg V, Vityazev Vladimir N
Applied Ultrasonics, Irondale, Birmingham, AL 35210, USA.
Ultrasonics. 2006 Dec 22;44 Suppl 1:e533-8. doi: 10.1016/j.ultras.2006.05.119. Epub 2006 Jun 6.
More and more experts and researchers in industry express their interest in the application of deformation effects of various peening techniques on the metal surface. This is primarily due to a relatively simple directional change in condition at the surface and in sub-surface layers of the material as a result of plastic deformation due to impulses of force caused, among other things, by converting ultrasonic oscillations of various impacting elements (indenters) at the treated surface. These effects are of a stochastic nature and their duration (or the time of impact) is generally measured in units of microseconds. To obtain relatively uniform coverage, an operator may use several treatment passes. However, a stochastic nature of single impacts makes it difficult to obtain a uniform distribution of deformations and hence surface characteristics as specified, in particular, by the engineering standards. We have developed the methods and means of implementing the ultrasonic impact and controlling its parameters. A fundamental distinction of the ultrasonic impact is that its duration is measured in the range from hundreds of microseconds to units of milliseconds, while the parameters responsible for the effects upon the surface may be adjusted according to the task. It is important to note that in the frequency range of processing ultrasound of up to 80 kHz this feature of the ultrasonic impact allows utilizing the plastic deformation region as a matched membrane to transmit ultrasonic oscillations and excite ultrasonic stress waves in the material being treated. These phenomena, in turn, initiate highly effective relaxation processes, plastic deformation and, as a result thereof, effects upon the structure and properties of the material, which are adequate to the task. This paper describes the theory and the results of the experimental investigations into the physics of the ultrasonic impact. Also, the mechanism of the ultrasonic impact implementation based on high-power ultrasonic transducers is addressed. The paper is aimed at engineers and researchers in the area of industrial application of high-power ultrasonics.
越来越多的行业专家和研究人员对各种喷丸技术的变形效应在金属表面的应用表现出兴趣。这主要是因为，由于诸如在处理表面转换各种冲击元件（压头）的超声振动等引起的力脉冲，材料表面和亚表面层的状态发生相对简单的方向变化。这些效应具有随机性，其持续时间（或冲击时间）通常以微秒为单位测量。为了获得相对均匀的覆盖，操作人员可能会进行多次处理。然而，单次冲击的随机性使得难以获得均匀的变形分布，从而难以获得工程标准所规定的特定表面特性。我们已经开发出了实施超声冲击及其参数控制的方法和手段。超声冲击的一个基本区别在于，其持续时间在数百微秒到毫秒量级范围内测量，而影响表面的参数可以根据任务进行调整。需要注意的是，在高达80kHz的处理超声频率范围内，超声冲击的这一特性使得可以利用塑性变形区域作为匹配膜来传输超声振动并在被处理材料中激发超声应力波。这些现象反过来又引发高效的松弛过程、塑性变形，并因此对材料的结构和性能产生与任务相适应的影响。本文描述了超声冲击物理过程的理论及实验研究结果。此外，还探讨了基于大功率超声换能器的超声冲击实施机制。本文面向大功率超声工业应用领域的工程师和研究人员。
