机械加工毕业设计外文翻译--微孔的加工方法(编辑修改稿)

机械加工毕业设计外文翻译--微孔的加工方法(编辑修改稿)内容摘要：

on endmill probably has 10 grains holding the core together,” Burton noted. He added that he has seen carbide powder containing grains, which is about half the size of what’s mercially available, but it also contained grains measuring and microns. “It just doesn’t help to have small grains if they’re not uniform.” Microvaporization Electrical discharge machining using a sinker EDM is another microholemaking option. Unlike , which create small holes for threading wire through the workpiece when wire EDMing, EDMs for producing microholes are considerably more sophisticated, accurate and, of course, expensive. For producing deep microholes, a tube is applied as the electrode. For EDMing smaller but shallower holes, a solid electrode wire, or rod, is needed. “We try to use tubes as much as possible,” said Jeff Kiszonas, EDM product manager for Makino Inc., Auburn Hills, Mich. “But at some point, nobody can make a tube below a certain diameter.” He added that some suppliers offer tubes down to in diameter for making holes as small as . The tube’s flushing hole enables creating a hole with a high depthtodiameter ratio and helps to evacuate debris from the bottom of the hole during machining. One such sinker EDM for producing holes as small as (11μm) is Makino’s Edge2 sinker EDM with finehole option. In Japan, the machine tool builder recently produced eight such holes in 2 minutes and 40 seconds through thick tungsten carbide at the hole locations. The electrode was a silvertungsten rod smaller than the hole being produced, to account for spark activity in the gap. When producing holes of that size, the rod, while rotating, is dressed with a charged EDM wire. The finehole option includes a Waxis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than . Another sinker EDM for microholemaking is the Mitsubishi VA10 with a finehole jig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standard （论文）外文翻译 5 EDM, but with that attachment fixed to the machine, we can do microhole drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale, Ill. He added that the EDM is also able to create holes down to using a wire that rotates at up to 2,000 rpm. Turn to Tungsten EDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, pany builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contractmachining basis. Optimation produces tungsten electrodes using a reversepolarity process and machines and ringlaps them to as small as 10μm in diameter with roundness. Applying a 10μmdia. electrode produces a hole about to 11μm in diameter, and blindholes are possible with the pany’s EDM. The workpiece thickness for the smallest holes is up to , and the thickness can be up to for 50μm holes. After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgensen decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000. Much of the pany’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for Xray apertures, stainless steel for optical applications and tantalum and tungsten for the electronbeam industry. Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD. “The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.。