The first-principles method based on the projector augmented wave method within the generalized gradient approximation was employed to calculate the superlattice intrinsic stacking fault（SISF） and complex stacking f...The first-principles method based on the projector augmented wave method within the generalized gradient approximation was employed to calculate the superlattice intrinsic stacking fault（SISF） and complex stacking fault（CSF） energies of the binary Ni3Al alloys with different Al contents and the ternary Ni3Al intermetallic alloys with addition of alloying elements,such as Pd,Pt,Ti,Mo,Ta,W and Re.The results show that the energies of SISF and CSF increase significantly with increase of Al contents in Ni3Al.Addition of Pd and Pt occupying the Ni sublattices does not change the SISF and CSF energies of Ni3Al markedly in comparison with the Ni-23.75Al alloy.While addition of alloying elements,such as Ti,Mo,Ta,W and Re,occupying the Al sublattices dramatically increases the SISF and CSF energies of Ni3Al.The results suggest that the energies of SISF and CSF are dependent both on the Al contents and on the site occupancy of the ternary alloying element in Ni3Al intermetallic alloys.展开更多
In this study,to address the low efficiency for conventional ultrasonic-assisted drlling(UAD)of carbon fiber-reinforced plastic and titanium alloy(CFRP/Ti)stacks,feasibility experiments of non-separation UAD,in which ...In this study,to address the low efficiency for conventional ultrasonic-assisted drlling(UAD)of carbon fiber-reinforced plastic and titanium alloy(CFRP/Ti)stacks,feasibility experiments of non-separation UAD,in which continuous cutting between the tool and the workpiece occurs at a high feed rate,are carried out.The experimental results indicate that,compared to conventional separation UAD,the non-separation UAD effectively reduces the cutting forces by 24.2%and 1.9%for CFRP stage and 22.1%and 2.6%for the Ti stage at the feed rates of 50 and 70μm/r,respectively.Furthermore,the non-separation UAD significantly improves hole quality,including higher hole diameter accuracy,lower hole surface roughness,and less hole damage.In addition,the non-separation UAD can decrease adhesive tool wear.This study demonstrates that,compared to conventional drilling(CD),the non-separation UAD can effectively improve drilling quality and tool life while maintaining high efficiency.展开更多
基金Project(50871065) supported by the National Natural Science Foundation of ChinaProjects(08DJ1400402,09JC1407200,10DZ2290904) supported by the Science and Technology Committee of Shanghai Municipality,China
文摘The first-principles method based on the projector augmented wave method within the generalized gradient approximation was employed to calculate the superlattice intrinsic stacking fault（SISF） and complex stacking fault（CSF） energies of the binary Ni3Al alloys with different Al contents and the ternary Ni3Al intermetallic alloys with addition of alloying elements,such as Pd,Pt,Ti,Mo,Ta,W and Re.The results show that the energies of SISF and CSF increase significantly with increase of Al contents in Ni3Al.Addition of Pd and Pt occupying the Ni sublattices does not change the SISF and CSF energies of Ni3Al markedly in comparison with the Ni-23.75Al alloy.While addition of alloying elements,such as Ti,Mo,Ta,W and Re,occupying the Al sublattices dramatically increases the SISF and CSF energies of Ni3Al.The results suggest that the energies of SISF and CSF are dependent both on the Al contents and on the site occupancy of the ternary alloying element in Ni3Al intermetallic alloys.
基金supported by the National Natural Science Foundation of China(Nos.52375399 and 91960203)the Aeronautical Science Foundation of China(No.2022Z045051001).
文摘In this study,to address the low efficiency for conventional ultrasonic-assisted drlling(UAD)of carbon fiber-reinforced plastic and titanium alloy(CFRP/Ti)stacks,feasibility experiments of non-separation UAD,in which continuous cutting between the tool and the workpiece occurs at a high feed rate,are carried out.The experimental results indicate that,compared to conventional separation UAD,the non-separation UAD effectively reduces the cutting forces by 24.2%and 1.9%for CFRP stage and 22.1%and 2.6%for the Ti stage at the feed rates of 50 and 70μm/r,respectively.Furthermore,the non-separation UAD significantly improves hole quality,including higher hole diameter accuracy,lower hole surface roughness,and less hole damage.In addition,the non-separation UAD can decrease adhesive tool wear.This study demonstrates that,compared to conventional drilling(CD),the non-separation UAD can effectively improve drilling quality and tool life while maintaining high efficiency.
