Performance and Wear Characteristics of Cutting Tool in Laser Ultrasonically Assisted Cutting of Cemented Carbides

硬質合金鐳射超聲輔助切削刀具性能及磨損特性

張昌娟(Chang-Juan Zhang) ； 焦鋒(Feng Jiao) ； 牛贏(Ying Niu)

《中國機械工程學刊》 39卷1期 (2018/02) Pp. 65-73

摘要

Laser ultrasonically assisted cutting (LUAC) for processing difficult-to-machine materials was proposed based on ultrasonically elliptical vibration cutting (UEVC) and laser assisted cutting (LAC), and experimentally compared with conventional cutting (CC), UEVC and LAC. The cutting performance of cemented carbides with different hardness using polycrystalline cubic boron nitride (PCBN) cutting tools was analyzed and wear mechanisms of the cutting tools was discussed by detecting tool wear conditions, cutting forces and surface morphology of workpiece and analyzing the energy spectrum of worn areas by scanning electron microscopy (SEM). The results showed that compared to CC, UEVC and LAC, LUAC showed significantly decreased cutting force, reduced tool wear, obviously prolonged tool life, and smoother surface quality of workpiece, especially for the cemented carbide with more cobalt elements. In addition, LUAC of cemented carbide was characterized by smooth and uniform crater on the rake face of the cemented carbide and narrow triangular wear land and shallow pits and scratches at the flank face of the cemented carbide. The failure mechanisms of PCBN cutting tool were the synergistic interaction among diffusive wear, adhesive wear, oxidation wear and abrasive wear.

關鍵字

cemented carbide ； laser ultrasonically assisted cutting ； ultrasonically elliptical vibration cutting ； laser assisted cutting ； tool wear

並列摘要

本研究基於鐳射加熱輔助切削和超聲振動切削提出了鐳射超聲輔助切削加工工藝，採用PCBN刀具對不同的硬質合金材料進行了普通切削，超聲振動切削，鐳射加熱輔助切削和鐳射超聲輔助切削對比試驗，對刀具磨損、切削力，工件表面形貌及刀具磨損區域的能譜進行了分析，對鐳射超聲輔助切削不同硬質合金材料時PCBN刀具的性能及磨損機理進行了研究。結果表明與普通切削、超聲振動切削及鐳射加熱輔助切削相比，鐳射超聲輔助切削過程中切削力減小，刀具磨損程度降低，工件表面品質提高；特別是鐳射超聲輔助切削鈷含量較高的硬質合金材料時，工件表面更加平整光滑，刀具使用壽命顯著提高。此外，採用PCBN刀具鐳射超聲輔助切削硬質合金時，刀具前刀面磨損呈現平滑且均勻的月牙窪，後刀面磨損呈現較窄的三角形磨損帶和較淺的凹坑和劃痕，擴散磨損、粘接磨損、氧化磨損和磨粒磨損共同導致了PCBN刀具的磨損。