单颗团聚CBN磨粒磨削TC4钛合金表面创成机制  

Grinding Surface Formation Mechanism of TC4 Titanium Alloy with a Single-aggregated CBN Grain

作　　者：赵彪 章敏秀 丁文锋[2] 李海 ZHAO Biao;ZHANG Min-xiu;DING Wen-feng;LI Hai(State Key Laboratory of Mechanical Transmissions,Chongqing University,Chongqing 400044,China;College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;AECC South Industry Co.,Ltd.,Hunan Zhuzhou 412002,China)

机构地区：[1]重庆大学机械传动国家重点实验室,重庆400044 [2]南京航空航天大学机电学院,南京210016 [3]中国航发南方工业有限公司,湖南株洲412002

出　　处：《表面技术》2023年第8期309-318,共10页Surface Technology

基　　金：机械传动国家重点实验室开放基金资助(SKLMT-MSKFKT-202101);航空发动机及燃气轮机基础科学中心项目(P2023-B-IV-003-001);国家自然科学基金青年项目(52205475);江苏省自然科学基金青年项目(BK20210295)。

摘　　要：目的提出一种兼具耐磨性好、自锐性能优异的新型团聚CBN磨粒研制方法,解决单晶CBN磨粒因其力学特性各向异性而极易出现沿解理面大块破碎的问题,进而提升加工效率和磨削性能。方法利用模压成形和高温液相烧结技术,制备了综合性能优异的新型团聚CBN磨粒,探究磨粒结合界面形成机制,并通过单颗磨粒磨削TC4钛合金试验,综合对比团聚CBN磨粒与单晶CBN磨粒的磨损状态和磨痕形貌,探明团聚CBN磨粒的磨削性能优势。结果团聚CBN磨粒烧结界面新生成了TiB_(2)、TiB和TiN;优选的烧结工艺参数为800℃,保温时间为10 min;相比于单晶CBN磨粒,团聚CBN磨粒的耐磨性和锋利度显著提升,磨削加工效率和质量明显改善。结论由于团聚CBN磨粒内部微晶颗粒间金属结合剂的存在,提高了磨粒的断裂韧性,降低了因磨粒内部裂纹扩展而引起的宏观裂纹损伤深度,有效提升了磨粒的加工性能;磨削过程中随着磨粒的不断磨损,未出露的CBN晶粒逐渐参与磨削,确保了磨粒工作面有效磨粒数的动态平衡,有助于提升磨粒整体自锐能力。High strength-toughness difficult-to-cut materials represented by titanium alloy and superalloy,exhibiting excellent properties,such as high-temperature strength,impact resistance,and great creep resistant performance,have opened up the increasing application as key materials of complex components in high thrust-to-weight ratio of modern aero-engine.Grinding process has become the major method to achieve the final forming surface of components.Compared to the problems,such as severe tool wear,low machining efficiency,and poor quality stability with conventional abrasive grinding wheels,the cubic boron nitride(CBN)superabrasive grinding wheel exhibiting unique advantages in the grinding of high strength-toughness difficult-to-cut materials.However,the grinding process is also facing the similar challenges,and then the root cause of these problems is the poor wear resistance and sharpening ability of traditional CBN abrasive wheels and thus the sharpness and tool life of CBN grinding wheel are not stable.The reason can be explained that these CBN grains possess anisotropic crystalline property,leading to the unfavorable macrofracture along the cleavage plane.In this case,the grinding performance and stability of CBN grains,as well as the surface precision and sharpness state of corresponding sintered wheels are severely affected,which restricts the improvement of machining efficiency.In order to improve the grinding performance of CBN grains,a new-type aggregated CBN grains coupled with great wear resistance and sharpening ability is proposed by employing cold press forming and high vacuum liquid-phase sintering techniques.In this work,the comparative grinding trials with a single grain for both aggregated and monocrystalline CBN grains were performed to study the grain wear behavior and material removal characteristics in grinding of Ti-6Al-4V alloys,in terms of the worn grain and grinding scratch morphologies.The strong bonding interface between metallic phases and Ti-coated CBN particles inside aggregated CBN gr

关 键 词：团聚CBN磨粒 TC4钛合金 微切削刃 磨痕形貌 锋利度 

分 类 号：TG580.6[金属学及工艺—金属切削加工及机床]