摘要
高硅铝合金由于硅含量很高,故切削加工性较差,切削刀具极易磨损且已加工表面存在大量缺陷。为进一步研究材料加工损伤,采用化学气相沉积法制备了金刚石涂层铣刀,开展70%Si/Al(70%指质量分数)合金材料铣削试验。试验研究了铣削力、刀具磨损及加工损伤机理,并与常用TiN涂层铣刀进行了对比。结果表明:铣削过程中由于初晶硅硬质颗粒的冲击和刻划,金刚石涂层刀具的失效形式主要是涂层剥落和磨粒磨损;在金刚石涂层铣刀的正常磨损阶段,铣削力稳定在43.57~48.95 N,而相同切削用量下TiN涂层铣刀的铣削力更大、刀具寿命更短;加工表面存在凹坑、划痕和颗粒破碎等损伤,在保证刃口强度的前提下适当减小切削刃圆弧半径可明显减小加工损伤;铣刀刃口圆弧半径r=12μm的已加工表面粗糙度(S_(a)=2.3μm)远低于r=156μm时加工的表面粗糙度(S_(a)=6.7μm)。
Due to the large amount of silicon particles,the machinability of the high-volume fraction silicon aluminum alloys was poor.Severe tool wear and deteriorated machined surfaces with defects were major problems in cutting high-volume fraction silicon aluminum materials.To further explore the machining damages,the milling experiments of 70%Si/Al(mass fraction is 70%)alloy were carried out,where the tools were prepared by chemical vapor deposition(CVD)method.Milling force,tool wear and mechanism of machining damages were investigated.As a comparison,milling tools with TiN coating were also utilized under identical cutting parameters.The results show that the main tool wear modes of the diamond coated tools are coating peeling and abrasive wear,which are due to the impact and scratching of hard silicon particles in milling processes.In the normal wear stages of the diamond coated tools,the milling force is stable in the range of 43.57~48.95 N,while the milling force of TiN coated tools is higher and the tool life is shorter.The damages on machined surfaces are mainly pits,scratches and ruptured particle.Under the premise of ensuring the strength of cutting-edge radius,machining damage may be obviously reduced by reducing the radius of tool cutting-edge.The surface roughness value(S_(a)=2.3μm)machined with a cutting-edge radius of 12μm is lower than that with a radius of 156μm(S_(a)=6.7μm).
作者
赵国龙
信连甲
李亮
王珉
郝秀清
何宁
ZHAO Guolong;XIN Lianjia;LI Liang;WANG Min;HAO Xiuqing;HE Ning(College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing,210016;Department of Geometric Measurement,Nanjing Institute of Measurement and Testing Technology,Nanjing,210049)
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2022年第2期153-159,共7页
China Mechanical Engineering
基金
国家自然科学基金(52075255,51975288)
南京航空航天大学研究生开放基金(kfjj20200505)。
