The blisk is a core component of an aero-engine,and electrochemical machining(ECM)is the primary method for its manufacture.Among several ECM methods for blisks,multi-tool synchronous machining is the most efficient a...The blisk is a core component of an aero-engine,and electrochemical machining(ECM)is the primary method for its manufacture.Among several ECM methods for blisks,multi-tool synchronous machining is the most efficient and advantageous for machining channels.The allowance distribution of the blank after blisk channel machining directly influences the blade profile accuracy.This paper proposes a trajectory control strategy to homogenize the allowance distribution of the blisk channel in multi-tool ECM.The strategy includes the design of the three-dimensional space motion of the tool and blisk,as well as the regulated feed speed.The structural characteristics of the blisk channel and the principle of ECM allow for designing and optimizing the multidimensional trajectory.The electric field simulations elucidate the influence law of the three-axis feed speed on the side gap.An algorithm is adopted to iteratively optimize the speeds for different positions to realize multi-dimensional motion control and allowance homogenization.The proposed trajectory control strategy is applied to ECM experiments for the blisk channel.Compared with the constant feed speed mode,the regulated speed strategy reduces the maximum allowance difference between the convex(CV)profiles by 36.18%and that between the concave(CC)profiles by 37.73%.Subsequently,the one-time ECM of eight blisk channels was successfully realized.The average time for a single channel was 12.5 min,significantly improving the machining efficiency.In conclusion,the proposed method is effective and can be extended for synchronously machining various blisk types with twisted channels.展开更多
A high-aspect-ratio microchannel heat exchanger based on multi-tool milling process was developed. Several slotting cutters were stacked together for simultaneously machining several high-aspect-ratio microchannels wi...A high-aspect-ratio microchannel heat exchanger based on multi-tool milling process was developed. Several slotting cutters were stacked together for simultaneously machining several high-aspect-ratio microchannels with manifold structures. On the basis of multi-tool milling process, the structural design of the manifold side height, microchannel length, width, number, and interval were analyzed. The heat transfer performances of high-aspect-ratio microchannel heat exchangers with two different manifolds were investigated by experiments, and the influencing factors were analyzed. The results indicate that the magnitude of heat transfer area per unit volume dominates the heat transfer performances of plate-type micro heat exchanger, while the velocity distribution between microchannels has little effects on the heat transfer performances.展开更多
现代金属切削加工正向着高速、高精度和高效的方向发展,对刀具的性能有着越来越高的要求。利用表面技术对刀具表面进行改性,是提高刀具性能和寿命的有效途径。使用多弧离子镀膜技术在YG6硬质合金以及三刃立铣刀表面制备了Cr Al N/CrN/Cr...现代金属切削加工正向着高速、高精度和高效的方向发展,对刀具的性能有着越来越高的要求。利用表面技术对刀具表面进行改性,是提高刀具性能和寿命的有效途径。使用多弧离子镀膜技术在YG6硬质合金以及三刃立铣刀表面制备了Cr Al N/CrN/Cr、TiAlN/CrN/Cr、Cr Al N/TiAlN/CrN/Cr三组涂层,并对三种涂层的制备技术、微观结构与性能差异、及耐磨与切削寿命提高机制进行研究。X射线衍射分析表明,三种涂层均为面心立方结构,其中TiAlN涂层表现出(200)晶面择优取向,而CrAlN和Cr Al N/TiAlN涂层则表现出(111)面的择优取向。使用显微硬度计和划痕仪对涂层的显微硬度和结合力进行测试,结果表明Cr Al N/TiAlN多层涂层的显微硬度和膜基结合力分别为2651 HV和59.2 N,显著高于TiAlN和CrAlN涂层。采用高温摩擦试验机评价了三种涂层的摩擦学性能,结果表明Cr Al N/TiAlN多涂层的摩擦性能优于TiAlN涂层和CrAlN涂层,室温下其平均摩擦因数和磨损率分别为0.603和2.92×10^(-6)mm^(3)(N·m)^(-1)。当温度增加到400℃时,Cr Al N/TiAlN涂层的平均摩擦因数进一步降低为0.467,磨损率增加至1.31×10^(-5)mm^(3)(N·m)^(-1)。铣削试验结果显示,TiAlN涂层刀具、CrAlN涂层刀具和Cr Al N/TiAlN涂层刀具的铣削寿命相对于无涂层刀具分别提升了80%、140%和200%,被加工样件的表面粗糙度分别降低至462 nm、415 nm和402 nm。研究结果表明Cr Al N/TiAlN涂层在现代切削加工领域有着良好的应用潜力。展开更多
基金co-supported by the National Natural Science Foundation of China(No.52075253)the National Natural Science Foundation of China for Creative Research Groups(No.51921003)the Industrial Technology Development Program(No.JCKY2021605B026)。
文摘The blisk is a core component of an aero-engine,and electrochemical machining(ECM)is the primary method for its manufacture.Among several ECM methods for blisks,multi-tool synchronous machining is the most efficient and advantageous for machining channels.The allowance distribution of the blank after blisk channel machining directly influences the blade profile accuracy.This paper proposes a trajectory control strategy to homogenize the allowance distribution of the blisk channel in multi-tool ECM.The strategy includes the design of the three-dimensional space motion of the tool and blisk,as well as the regulated feed speed.The structural characteristics of the blisk channel and the principle of ECM allow for designing and optimizing the multidimensional trajectory.The electric field simulations elucidate the influence law of the three-axis feed speed on the side gap.An algorithm is adopted to iteratively optimize the speeds for different positions to realize multi-dimensional motion control and allowance homogenization.The proposed trajectory control strategy is applied to ECM experiments for the blisk channel.Compared with the constant feed speed mode,the regulated speed strategy reduces the maximum allowance difference between the convex(CV)profiles by 36.18%and that between the concave(CC)profiles by 37.73%.Subsequently,the one-time ECM of eight blisk channels was successfully realized.The average time for a single channel was 12.5 min,significantly improving the machining efficiency.In conclusion,the proposed method is effective and can be extended for synchronously machining various blisk types with twisted channels.
基金Projects(50675070 50805052) supported by the National Nature Science Foundation of China+1 种基金Projects(07118064 8451064101000320) supported by the Natural Science Foundation of Guangdong Province
文摘A high-aspect-ratio microchannel heat exchanger based on multi-tool milling process was developed. Several slotting cutters were stacked together for simultaneously machining several high-aspect-ratio microchannels with manifold structures. On the basis of multi-tool milling process, the structural design of the manifold side height, microchannel length, width, number, and interval were analyzed. The heat transfer performances of high-aspect-ratio microchannel heat exchangers with two different manifolds were investigated by experiments, and the influencing factors were analyzed. The results indicate that the magnitude of heat transfer area per unit volume dominates the heat transfer performances of plate-type micro heat exchanger, while the velocity distribution between microchannels has little effects on the heat transfer performances.
文摘现代金属切削加工正向着高速、高精度和高效的方向发展,对刀具的性能有着越来越高的要求。利用表面技术对刀具表面进行改性,是提高刀具性能和寿命的有效途径。使用多弧离子镀膜技术在YG6硬质合金以及三刃立铣刀表面制备了Cr Al N/CrN/Cr、TiAlN/CrN/Cr、Cr Al N/TiAlN/CrN/Cr三组涂层,并对三种涂层的制备技术、微观结构与性能差异、及耐磨与切削寿命提高机制进行研究。X射线衍射分析表明,三种涂层均为面心立方结构,其中TiAlN涂层表现出(200)晶面择优取向,而CrAlN和Cr Al N/TiAlN涂层则表现出(111)面的择优取向。使用显微硬度计和划痕仪对涂层的显微硬度和结合力进行测试,结果表明Cr Al N/TiAlN多层涂层的显微硬度和膜基结合力分别为2651 HV和59.2 N,显著高于TiAlN和CrAlN涂层。采用高温摩擦试验机评价了三种涂层的摩擦学性能,结果表明Cr Al N/TiAlN多涂层的摩擦性能优于TiAlN涂层和CrAlN涂层,室温下其平均摩擦因数和磨损率分别为0.603和2.92×10^(-6)mm^(3)(N·m)^(-1)。当温度增加到400℃时,Cr Al N/TiAlN涂层的平均摩擦因数进一步降低为0.467,磨损率增加至1.31×10^(-5)mm^(3)(N·m)^(-1)。铣削试验结果显示,TiAlN涂层刀具、CrAlN涂层刀具和Cr Al N/TiAlN涂层刀具的铣削寿命相对于无涂层刀具分别提升了80%、140%和200%,被加工样件的表面粗糙度分别降低至462 nm、415 nm和402 nm。研究结果表明Cr Al N/TiAlN涂层在现代切削加工领域有着良好的应用潜力。
