摘要
针对弹性磨料射流加工与硬质磨料射流加工钝化处理方法对陶瓷刀具的影响展开研究,观察表面形貌以及刃口钝圆半径的变化,通过Inconel 718镍基高温合金车削实验进行对比分析,研究不同刃口结构对刀具寿命的影响。实验结果表明:弹性喷砂与湿喷砂的工艺参数对刃口处表面粗糙度、刃口钝圆半径以及残余应力具有显著影响。在喷嘴角度固定的条件下,300 kPa的压强在钝化处理过程中表现出最佳效果,表面粗糙度最大可降低45%。经钝化处理后的刃口表面质量得到显著提升,未钝化处理的刀具后刀面磨损以黏着磨损为主,优化后的车刀能够有效抑制刃尖端处碎屑的沉积,减缓刀具磨损速率,钝圆半径R为15μm的优化方案刀具寿命提升最为明显,增益高达29%。
Objective:Ceramic tools exhibit great potential in high-speed cutting of difficult-to-machine materials like nickel-based superalloys due to their excellent red hardness and low chemical affinity.However,their inherent brittleness leads to easy chipping at the cutting edge,severely limiting tool life and machining stability.When traditional hard abrasive passivation methods are applied to ceramic tools,they tend to cause subsurface damage,and the quantitative relationship between passivation parameters and cutting-edge performance remains unclear.Therefore,this study systematically compares the effects of two passivation processes-elastic abrasive jet and hard abrasive jet-on the edge morphology,surface integrity,and cutting performance of ceramic tools.It aims to reveal the influence mechanisms of different passivation methods on tool life,identify the optimal passivation parameter combinations,and provide theoretical and technical support for efficient and controllable passivation of ceramic tools.Methods:This study uses uncoated cermet inserts as experimental subjects.Passivation is performed using a self-developed elastic blasting device and a wet micro-blasting machine.The elastic abrasive is composed of polyurethane,silicone rubber,and diamond micro-powder,offering good elasticity and grinding capability.The hard abrasive is a 10%volume fraction white corundum solution.By adjusting the blasting pressure and blasting time,the influence of process parameters on the edge radius,surface roughness,and residual stress is systematically studied.After passivation,an Alicona 3D profilometer is used to measure the edge radius and surface roughness,and an X-ray diffractometer is employed to detect surface residual stress.Based on this,inserts with different edge radii(5~30μm)are selected for dry turning experiments on Inconel 718.The cutting parameters are fixed as follows:cutting speed 100 m·min^(-1),feed rate 0.3 mm·s^(-1),and depth of cut 0.3 mm.Tool flank wear is periodically observed using a Keyence VHX-7000 microscope,and wear morphology is analyzed using scanning electron microscopy(SEM)to systematically evaluate the impact of different passivation treatments on tool life and wear mechanisms.Results:Experimental results show that passivation process parameters significantly affect the surface properties of the tools.In terms of edge radius,both elastic blasting and wet blasting increase the edge radius with increasing blasting time and pressure.However,the maximum radius achieved by elastic blasting is smaller,indicating a gentler material removal characteristic.Under 300 kPa condition,the edge radius increases from about 8μm to about 17μm after 120 s of elastic blasting,while wet blasting could achieve a larger radius within the same time but with a higher risk of impact damage.Regarding surface roughness,elastic blasting at 300 kPa for 60~90 s reduces the roughness from Ra 0.120μm to Ra 0.066μm,a decrease of 45%,demonstrating the best surface finishing effect.Wet blasting achieves the maximum reduction at 200 kPa for 20 s,but excessively long times or high pressures leads to a decline in surface quality.In terms of residual stress,both processes introduce compressive stress.Wet blasting increases the residual stress to-907.6 MPa within 50 s,whereas elastic blasting reaches only-660.4 MPa after 150 s,indicating that hard abrasives can generate high compressive stress more quickly.Conclusion:Both elastic blasting and wet blasting can effectively improve the edge quality of tools.Among them,elastic blasting at 300 kPa for 60~90 s achieves the best comprehensive surface quality,reducing surface roughness by 45%while maintaining edge integrity.The edge radius significantly influences tool life,with R=15μm being the optimal value.A radius that is too small tends to cause adhesive wear,while one that is too large leads to increased cutting forces and early chipping.Due to its gentle grinding characteristics,elastic blasting outperforms wet blasting in suppressing adhesive wear and maintaining edge integrity,making it more suitable for precision passivation of ceramic tools.By optimizing passivation parameters,synergistic control of the surface morphology,residual stress,and edge structure of ceramic tools can be achieved,ultimately increasing tool life by up to 29%.This provides a reliable process foundation for the broader application of ceramic tools in superalloy machining.Other:As a pioneering study,this research contrasts elastic and hard abrasive jet passivation for ceramic tools.The edge morphology-based optimization strategy presented here offers clear guidelines for practice and presents a significant step towards broader adoption of high-performance ceramic tools.
作者
刘睦彬
吴志正
庄可佳
LIU Mubin;WU Zhizheng;ZHUANG Kejia(School of Mechanical and Electronic Engineeering,Wuhan University of Technology,Wuhan 430070)
出处
《工具技术》
北大核心
2026年第2期11-20,共10页
Tool Engineering
基金
国家自然科学基金(52475529)。
