Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge. Electrochemical machining is an important issue in the fabri...Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge. Electrochemical machining is an important issue in the fabrication of titanium and titanium alloys. Wire electrochemical machining （WECM） is mainly used for workpiece cutting under the condition of different thickness plates. It has a great advantage over wire electro-discharge machining, which is the absence of heat-affected zone around the cutting area. Moreover, the wire electrode in WECM could be used repetitively because it is not worn out. Thus, much attention has been paid to WECM. The effective way of removing electrolysis products is of importance to WECM. In this paper, the axial electrolyte flushing is presented to WECM for removing electrolysis products and renewing electrolyte. The Taguchi experiment is conducted to optimize the machining parameters, such as wire feedrate, machining voltage, electrolyte concentration, etc. Experimental results show that WECM with axial electrolyte flushing is a promising issue in the fabrication of titanium alloy （TC1）. The feasibility of multi-wire electrochemical machining is also demonstrated to improve the machining productivity of WECM.展开更多
以φ1.2 mm TC4钛合金焊丝为原材料,通过激光同轴送丝增材制造技术,结合蛇形正交路径,系统研究了增材试件在不同方向和高度下的力学性能、截面形貌、晶粒度和晶粒取向等之间的联系。研究结果表明,优化工艺参数下,试件表面成形良好(银白...以φ1.2 mm TC4钛合金焊丝为原材料,通过激光同轴送丝增材制造技术,结合蛇形正交路径,系统研究了增材试件在不同方向和高度下的力学性能、截面形貌、晶粒度和晶粒取向等之间的联系。研究结果表明,优化工艺参数下,试件表面成形良好(银白色、无飞溅),内部无气孔、裂纹等缺陷(满足NB/T 47014.2—2015 I级要求)。微观组织分析显示,增材试样底部因多次热循环形成细小网篮组织,中上部的双态组织和魏氏组织特征更为明显。晶粒取向差随高度增加而减小(底部X/Y向分别为45.9°/43.1°,顶部降至37.8°/35.9°)。力学性能测试表明,横向与纵向的抗拉强度(差异2.57%)、断后伸长率(差异4.44%)及冲击韧性(52.6 J和55.3 J)均满足CCS《材料焊接与规范2023》中对TC4板材的要求。此外,由于增材过程中热循环的影响,下层沉积组织晶粒尺寸较小,硬度较高。增材试件在横向和纵向的晶粒度、晶粒取向和组织形态相近,力学性能的各向异性较小。本研究为TC4钛合金激光同轴送丝增材制造技术的工程化应用提供了重要的实验依据。展开更多
基金financial support from the National Natural Science Foundation of China (No. 51005120)Jiangsu Natural Science Foundation (Nos. BK2010508 and BE2010193)
文摘Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge. Electrochemical machining is an important issue in the fabrication of titanium and titanium alloys. Wire electrochemical machining （WECM） is mainly used for workpiece cutting under the condition of different thickness plates. It has a great advantage over wire electro-discharge machining, which is the absence of heat-affected zone around the cutting area. Moreover, the wire electrode in WECM could be used repetitively because it is not worn out. Thus, much attention has been paid to WECM. The effective way of removing electrolysis products is of importance to WECM. In this paper, the axial electrolyte flushing is presented to WECM for removing electrolysis products and renewing electrolyte. The Taguchi experiment is conducted to optimize the machining parameters, such as wire feedrate, machining voltage, electrolyte concentration, etc. Experimental results show that WECM with axial electrolyte flushing is a promising issue in the fabrication of titanium alloy （TC1）. The feasibility of multi-wire electrochemical machining is also demonstrated to improve the machining productivity of WECM.
