加工钛合金大口径深盲孔的研究

钛合金属难加工材料,其深孔加工的难度更为突出,加工质量不易保证。本文通过实验对比,对加工钛合金大口径深盲孔中出现的偏孔、切屑堵塞、切削振动、刀具破损等主要问题进行了分析,提出了解决办法,得出了切削用量的优化参数。由于钛合金的化学亲和作用,深孔加工刀具的导向条表面易于粘附,结果拉伤已加工表面,造成表面粗糙度上升。加大导向条与孔壁的间隙虽可减少导向条表面的粘附,但同时会引起切削振动的加剧。针对这一矛盾,本文着重对加工刀具的导向条分布、导向条与孔壁的间隙以及导向条的选材方面进行了探讨,提出了以非金属导向条代替硬质合金导向条进行钛合金深孔精加工的方法,使得已加工表面的粗糙度大大降低。这些研究结果对实际加工具有一定的指导作用。

A Study on Drilling Large Blind Deep Holes of Titanium Alloys

It is difficult to machine titanium alloys, especially to drill deep holes on them with high quality. In this paper, by means of experimental comparison, some important problems such as drilled slant holes, blocked chips, and vibration and tool breakage which are often found in the process of drilling large, blind and deep holes of titanium alloys, are analysed and solved) meanwhile the optimum cutting conditions are obtained. Because of the drastic chemical affinity of titanium alloys, the guide bars on the tools are easily glued by titanium alloy materials so that the machined surfaces of the holes are damaged. Extending the gap between the guide bar and the surface of the hole can decrease the adhesion, but at the same time the machining vibration will increase. In connection with this problem, the paper focuses studies on the guide bar distribution, the gap between the guide bar and the 'hole surface, as well as the guide bar materials, and gives a method in finish machining of deep hole of titanium alloys by nonmetal guide bars instead of by carbide ones, so that the roughness of the machined surface is decreased. All these results will be a useful guide in practical processes.