APPLICATION OF ABRASIVE-WATERJET FOR 3D MACHINING

摘要

Abrasive-waterjet (AWJ) is inherently not suitable for complex 3D machining because of the difficulty in capturing the spent abrasives in a three-dimensional space. The spent abrasives still possess considerable residue cutting power that is not only capable of damaging the target workpiece but also a potential safety hazard to the operators. Designing an optimum catcher for a 3D AWJ system to mitigate damage to the target workpiece with complex 3D features is nearly impossible. Although there are commercial multi-axis 3D AWJ systems, they are only limited to machining relatively simple 3D parts. On the other hand, AWJ is amenable to 3D machining. Approaches to take advantage of the 3D machining capability of AWJ while operating within the limitations of safety are discussed in this paper. Generally, the approaches can be divided into two main categories, those with and those without the requirement of added accessories, respectively. For the approach requiring no additional accessories, the workpieces have to be cut multiple times at different orientations or rely on secondary processes to transform them from 2D to 3D shapes. For a number of applications, special accessories were designed to be mounted on the 2D AWJ platform to facilitate 3D machining. PC-based control software was developed to control the operations of these accessories for automation. Machining processes based on these approaches were developed to facilitate 3D machining using a 2D AWJ platform such that the spent abrasives were always shooting in a generally downward direction toward the machine's water tank. By combining more than one accessory, 3D parts with very complex features can be readily machined. Sample 3D parts machined with the above processes are presented to demonstrate the versatility and advantages of AWJ 3D machining.