In this research, we have successfully developed a low-pulse energy laser shock peening (LSP) technology and applied it to WC-8Co cemented carbide tools, aiming to significantly enhance their mechanical performance. Through a systematic investigation, we explored the effects of laser power and the number of scanning passes on the mechanical properties and microstructure of the tools, as well as the underlying strengthening and toughening mechanisms of LSP. Our findings reveal that when the laser power was optimized at 0.4 mj and the tool was subjected to 2 scanning passes during LSP treatment, there was a remarkable improvement in the tool's flexural strength and hardness, increasing by 27.9 % and 39.8 %, respectively. This study underscores the potential of LSP as an effective method for improving the performance of cemented carbide tools. The relative density reached 98.1 %, grain size reduced to 1.06 μm, and residual compressive stress reached -1871MPa. Additionally, under the induction of low-pulse energy, a multi-level construction of material microstructures is achieved, resulting in a unique non-uniform grain structure along the depth direction with a gradient distribution. This effectively inhibits the initiation and propagation of cracks, thus significantly enhancing the mechanical properties of the tool. These findings, applicable to cemented carbide tool materials, open up new avenues for the development of novel high-performance tools for high-speed machining.

中文翻译：

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激光冲击强化 WC-8Co 硬质合金的微观组织调控及强化增韧机理研究


在这项研究中，我们成功开发了一种低脉冲能量激光冲击强化 （LSP） 技术，并将其应用于 WC-8Co 硬质合金工具，旨在显着提高其机械性能。通过系统研究，我们探讨了激光功率和扫描通道次数对工具机械性能和微观结构的影响，以及 LSP 的潜在强化和增韧机制。我们的研究结果表明，当激光功率优化为 0.4 mj 并在 LSP 处理期间对工具进行 2 次扫描时，工具的弯曲强度和硬度有显着提高，分别提高了 27.9% 和 39.8%。本研究强调了 LSP 作为提高硬质合金工具性能的有效方法的潜力。相对密度达到 98.1 %，晶粒尺寸减小到 1.06 μm，残余压应力达到 -1871MPa。此外，在低脉冲能量的感应下，实现了材料微观结构的多级构建，从而沿深度方向产生了具有梯度分布的独特不均匀晶粒结构。这有效地抑制了裂纹的萌生和扩展，从而显着提高了工具的机械性能。这些发现适用于硬质合金刀具材料，为开发用于高速加工的新型高性能刀具开辟了新的途径。