增减材复合加工TC4高精度孔试验对比研究  

Comparative Study on High-precision Hole Test of TC4 Titanium Alloy by Additive and Subtractive Materials

作　　者：石文天[1] 李季杭 刘玉德[1] 闫天明 林宇翔 王林[1] SHI Wen-tian;LI Ji-hang;LIU Yu-de;YAN Tian-ming;LIN Yu-xiang;WANG Lin(School of Artificial Intelligence,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]北京工商大学人工智能学院,北京100048

出　　处：《表面技术》2022年第11期347-359,共13页Surface Technology

基　　金：国家自然科学基金(51975006,51505006)。

摘　　要：目的提升增材制造钛合金孔的表面精度和质量。方法在一定的切削速度下,通过改变进给速度,对比分析经选区激光熔化(Selective Laser Melting,SLM)成形的试样采用直接钻削和成形预制孔后再钻削的加工方式后,试样的表面质量、尺寸精度和切削力信号等的变化情况。结果SLM成形原始孔的实际尺寸普遍小于理论尺寸,主要原因是其存在塌陷区域和粉末黏附区。采用进给速度20 mm/min并配合SLM成孔后再加工的方式,得到的孔结构的加工质量表现相对最好,毛刺相对最少,尺寸误差最低达到了22μm,且轴向切削力整体最低,最大切削力下降了约29%,平均切削力下降了约61%。经增材制造成形再进行钻削加工后,其整体切削力显著低于对增材板件直接钻削的切削力,且前者切削力的波动相较于后者更大,并具有一定的周期性。经SLM成孔后,再采用钻削加工后,刀具更加耐破损,但是其耐磨损性较差,主要原因是刀具与残留在原始孔周围的金属粉末相互摩擦,加剧了刀具的磨损。SLM成孔后再钻削加工方式会产生离散的粒状和节状切屑,且其尺寸普遍较小,宽度为30μm左右,切屑可以被有效排出,减少了积热;在直接加工方式下主要为带状切屑,切屑连续且尺寸较大,宽度为300μm左右,这不利于切屑的排出,导致刀具排屑困难、积热严重。结论增减材复合加工TC4钛合金可以获得高精度孔,且其尺寸误差最低为22μm。The work aims to improve the hole accuracy and quality of additively manufactured titanium alloys. At a certain cutting speed, by changing the size of the feed rate, three kinds of processing were performed on the original hole formed by SLM(selective laser melting), the direct drilling of the additive plate, and the drilling after the SLM. Through comparative analysis, the surface quality, dimensional accuracy, and cutting force signal changes after machining were studied by different methods. The result was that the actual size of the original pores formed by SLM was generally smaller than the theoretical size,mainly due to the existence of the collapsed area and the powder adhesion area. With a feed rate of 20 mm/min and SLM after hole formation, the hole structure had the best processing quality and the least burr.Drilling can significantly improve the dimensional accuracy of the SLM-formed hole structure. The parameters of the cutting speed of 47 m/min and the feed rate of 20 mm/min were matched with the parameters of the SLM drilling method and the processing quality of the sample hole structure after drilling. The minimum dimensional error was 22 μm. Compared with direct drilling, the dimensional accuracy was improved by 40.5%. In the processing method of direct drilling of the additive plate, due to the extrusion between the secondary cutting edge of the tool and the hole wall, the hole wall would produce large cracks, and the pores caused the hole wall collapse. However, this phenomenon was improved in SLM drilling and then drilling processing methods. The dimensional error was as low as 22 μm, and the overall axial cutting force was the lowest, the maximum cutting force reduction percentage was 29%, and the average cutting force reduction percentage was 61%. The overall cutting force of drilling after additive manufacturing was significantly lower than the cutting force of direct drilling of the additive sheet. The fluctuation of the former cutting force was higher than that of the latter and had a ce

关 键 词：增减材复合加工 钛合金 高精度孔 表面质量 

分 类 号：TG506.7[金属学及工艺—金属切削加工及机床]