Cubic boron nitride(cBN)grinding wheels play a pivotal role in precision machining,serving as indispensable tools for achieving exceptional surface quality.Ensuring the sharpness of cBN grains and optimizing the grind...Cubic boron nitride(cBN)grinding wheels play a pivotal role in precision machining,serving as indispensable tools for achieving exceptional surface quality.Ensuring the sharpness of cBN grains and optimizing the grinding wheel’s chip storage capacity are critical factors.This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method.It investigates the impact of blasting parameters-specifically silicon carbide(SiC)abrasive size,blasting distance,and blasting time-on the erosive wear characteristics of both the metal bond and abrasive.The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond.Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains,optimal parameters for the working layer are determined:a blasting distance of 60 mm,a blasting time of 15 s,and SiC particle size of 100#.Furthermore,an advanced simulation model investigates the dressing process of abrasive blasting,revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains,thereby enhancing fracture toughness and impact resistance.Additionally,a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels.The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force,temperature,and chip adhesion,thereby enhancing the surface quality of the workpiece.展开更多
The machining surface integrity of aero-engine turbine disc slots has a significant impact on their fatigue life and service performance,and achieving efficiency and high-precision machining is still a great challenge...The machining surface integrity of aero-engine turbine disc slots has a significant impact on their fatigue life and service performance,and achieving efficiency and high-precision machining is still a great challenge.The high machining requirements of future aeroengine turbine disc slots will be difficult to satisfy using the broaching method.In addition,existing methods of slot machin-ing face difficulties in ensuring surface integrity.This study explored a cup shaped electroplated Cubic Boron Nitride(CBN)abrasive wheel for profile grinding the turbine disc slots of FGH96 powder metallurgy superalloy.The matrix structure of the cup shaped abrasive wheel was designed and verified.A profile grinding experiment was conducted for fir-tree slots on a five-axis machining center.The accuracy and the surface integrity were analyzed.Results show that the key dimension detection results of the slots were within the allowable tolerance range.Meanwhile,an average sur-face roughness Ra of 0.55μm was achieved,the residual stress was compressive,the plastic defor-mation layer thickness was less than 5μm,and the hardening layer thickness was less than 20μm.The research findings provide a new approach to machining the slots of aviation engine turbine discs and guidance for the high-quality processing of complex components.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.92160301,92060203,52175415,52205475,and 52205493)Science Center for Gas Turbine Project(Grant Nos.P2022-AB-IV-002-001 and P2023-B-IV-003-001)+3 种基金Jiangsu Provincial Natural Science Foundation(Grant No.BK20210295)the Huaqiao University Engineering Research Center of Brittle Materials Machining(Grant No.2023IME-001)Foundation of Graduate Innovation Centre in NUAA(Grant No.XCXJH20230509)Fundamental Research Funds for the Central Universities(Grant Nos.NS2023028 and NG2024015).
文摘Cubic boron nitride(cBN)grinding wheels play a pivotal role in precision machining,serving as indispensable tools for achieving exceptional surface quality.Ensuring the sharpness of cBN grains and optimizing the grinding wheel’s chip storage capacity are critical factors.This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method.It investigates the impact of blasting parameters-specifically silicon carbide(SiC)abrasive size,blasting distance,and blasting time-on the erosive wear characteristics of both the metal bond and abrasive.The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond.Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains,optimal parameters for the working layer are determined:a blasting distance of 60 mm,a blasting time of 15 s,and SiC particle size of 100#.Furthermore,an advanced simulation model investigates the dressing process of abrasive blasting,revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains,thereby enhancing fracture toughness and impact resistance.Additionally,a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels.The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force,temperature,and chip adhesion,thereby enhancing the surface quality of the workpiece.
基金supported by the National Natural Science Foundation of China (Nos.52305477,52375447,52305474)Major Special Projects of Aero-engine and Gas Turbine (No.2017-VII-0002-0095)+4 种基金the Special Fund of Taishan Scholars Project (No.tsqn202211179)the Youth Talent Promotion Project in Shandong (No.SDAST2021qt12)the Natural Science Foundation of Shandong Province (Nos.ZR2023QE057,ZR2022QE028,ZR2021QE116,and ZR2020KE027)Qingdao Science and Technology Planning Park Cultivation Plan (No.23-1-5-yqpy-17-qy)the Natural Science Foundation of Jiangsu Province (No.BK20210407).
文摘The machining surface integrity of aero-engine turbine disc slots has a significant impact on their fatigue life and service performance,and achieving efficiency and high-precision machining is still a great challenge.The high machining requirements of future aeroengine turbine disc slots will be difficult to satisfy using the broaching method.In addition,existing methods of slot machin-ing face difficulties in ensuring surface integrity.This study explored a cup shaped electroplated Cubic Boron Nitride(CBN)abrasive wheel for profile grinding the turbine disc slots of FGH96 powder metallurgy superalloy.The matrix structure of the cup shaped abrasive wheel was designed and verified.A profile grinding experiment was conducted for fir-tree slots on a five-axis machining center.The accuracy and the surface integrity were analyzed.Results show that the key dimension detection results of the slots were within the allowable tolerance range.Meanwhile,an average sur-face roughness Ra of 0.55μm was achieved,the residual stress was compressive,the plastic defor-mation layer thickness was less than 5μm,and the hardening layer thickness was less than 20μm.The research findings provide a new approach to machining the slots of aviation engine turbine discs and guidance for the high-quality processing of complex components.
