The potential of friction stir forming for joining dissimilar grades of aluminum alloys namely,AA 5052-H32 and AA 6061-T6,was investigated.Study on the effect of tool plunge depth revealed that,lap shear load of 7.16 ...The potential of friction stir forming for joining dissimilar grades of aluminum alloys namely,AA 5052-H32 and AA 6061-T6,was investigated.Study on the effect of tool plunge depth revealed that,lap shear load of 7.16 kN and cross-tensile load of 3.51 kN,recorded at medium tool plunge depth range from 0.5 to 0.7 mm,measured using a universal testing machine,were much larger than those of friction stir welded and friction stir spot welded joints fabricated on the same materials.Joint macrostructure observed with optical microscope revealed that joints were strengthened either by mechanical pin interlocking or by metallurgical bonding.The effect of tool plunge depth on the stir zone formation and the influence of frictional heat flux on the lower sheet were revealed through the microhardness measurement using Vickers hardness tester.Morphological studies revealed that tool plunge depth has a significant influence on the pin formation and the geometric features,generated in these joints.Occurrence of various failure modes such as pin pull-out,pin shear,partial bond delamination,and tear-off,were governed by the formation of critical weak zones at various tool plunge depths.展开更多
Optical pickup is the core of optical disc device, which reads laser ray reflected from a disk surface. To immediately suppress the vibration caused inside or outside of the device and the counteraction of the servo f...Optical pickup is the core of optical disc device, which reads laser ray reflected from a disk surface. To immediately suppress the vibration caused inside or outside of the device and the counteraction of the servo function, a damper agent that absorbs vibration is used. This paper focuses on a damper agent developed by Three Bond Co., Ltd., introducing its purpose, its required properties, and the method by which it has been evaluated.展开更多
文摘The potential of friction stir forming for joining dissimilar grades of aluminum alloys namely,AA 5052-H32 and AA 6061-T6,was investigated.Study on the effect of tool plunge depth revealed that,lap shear load of 7.16 kN and cross-tensile load of 3.51 kN,recorded at medium tool plunge depth range from 0.5 to 0.7 mm,measured using a universal testing machine,were much larger than those of friction stir welded and friction stir spot welded joints fabricated on the same materials.Joint macrostructure observed with optical microscope revealed that joints were strengthened either by mechanical pin interlocking or by metallurgical bonding.The effect of tool plunge depth on the stir zone formation and the influence of frictional heat flux on the lower sheet were revealed through the microhardness measurement using Vickers hardness tester.Morphological studies revealed that tool plunge depth has a significant influence on the pin formation and the geometric features,generated in these joints.Occurrence of various failure modes such as pin pull-out,pin shear,partial bond delamination,and tear-off,were governed by the formation of critical weak zones at various tool plunge depths.
文摘Optical pickup is the core of optical disc device, which reads laser ray reflected from a disk surface. To immediately suppress the vibration caused inside or outside of the device and the counteraction of the servo function, a damper agent that absorbs vibration is used. This paper focuses on a damper agent developed by Three Bond Co., Ltd., introducing its purpose, its required properties, and the method by which it has been evaluated.
