采用高速充液旋压-多级拉拔复合成形方法加工出了直径在6mm以下的、质量稳定的微型直齿沟槽铜管.在分析其加工成形机理的基础上,研究了加工参数对沟槽铜管质量的影响.结果表明：微型直齿沟槽铜管成形过程中,过大的拉拔级次压缩率会导致微型直齿沟槽铜管的轴向沟槽产生断裂或折叠,过大的圆度误差会导致微型直齿沟槽铜管表面产生皱折和凹陷;而拉拔模具入口锥角采用16°、定径区长度取4mm、出口锥角取30°、润滑条件良好及残余应力较小时,拉拔沟槽铜管表面质量更高.通过控制拉拔工艺参数和圆度误差,可获得直径在6mm以下的、质量稳定的微型直齿沟槽铜管,且内部沟槽趋于封闭,呈燕尾槽特征,有利于提高微型直齿沟槽铜管的毛细力.

High-quality copper tube with micro straight grooves,which is less than 6mm in outer diameter,was fabricated via the composite process of high-speed oil-filled spinning and multi-pass drawing.Then,the corresponding machining mechanism was analyzed,and the influences of machining parameters on the quality of the product were investigated.The results indicate that,during the machining,excessive drawing reduction may result in groove folding and crack,and excessive roundness error may lead to crinkle even depression;and that,when the entry cone angle of the drawing die is 16°,the length of sizing region is 4mm and the exit cone angle of the drawing die is 30°,high-quality copper tube with micro straight grooves can be machined under good lubrication condition and small residual stress.Moreover,it is found that stable-quality copper tube with micro straight grooves,which is less than 6mm in outer diameter,can be machined by controlling the drawing parameters and the roundness error.The inner grooves of the product tend to close,just like a dovetail,which benefits the improvement of capillary force of the tube.