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We have developed a small size and high strength spiral bevel gear fabricated by five-axis controlled machining center. In the present report, we propose a novel spiral bevel gear with the rib at the end of face width to reinforce the tooth bending strength, which is machined with a ball-nose end-mill tool. We investigate the influence of the triangular rib on the bending stress both at the tooth root and around the rib and tooth deflection based on 1DCAE model, and demonstrate the effect of rib reinforcement at the proposed spiral bevel gear. Moreover, we compare the calculated stresses by 1DCAE with experimental ones from fabricated spiral bevel gear. As a result, a novel guideline is found to develop the small size and high strength spiral bevel gear with the rib at the end of face width from a view of rib shape.

We have developed a small size and high strength spiral bevel gear fabricated by five axis controlled machining center. In the present report, we propose a novel spiral bevel gear with the rib at the end of face width to reinforce the tooth bending strength, which is machined with a ball-nose end-mill tool. We investigate the influence of the rib shape on the bending stress at the tooth root based on 1D-CAE model and demonstrate the effect of rib reinforcement at the proposed spiral bevel gear. As a result, a novel guideline is found to design the small size and high strength spiral bevel gear with the rib at the end of face width from a view of rib shape.

WC-Co ultrafine-grained cemented carbide with the combined addition of Ti(C,N) and Cr3C2 was studied for microstructure and mechanical properties. In particular, the strength (transverse rupture strength) of the alloy was examined in detail comparing it with other kinds of cemented carbides. The WC grain size of the alloy with the single addition of Ti(C,N) or Cr3C2 became finer with increasing the amount of the additive. The combined addition of Ti(C,N) and Cr3C2 made the WC grain size further finer and the microstructure more homogeneous. The hardness of Ti(C,N)-Cr3C2 added alloys increased with decreasing the average grain size of WC or the mean free path of the binder phase, but the fracture toughness decreased. The strength of Ti(C,N)-Cr3C2 added alloy varied depending on the amount of the additive. It was noted that the strength of 3 vol%Ti(C,N)-0.5 vol%Cr3C2 alloy was the best and reached 4.6 GPa on average and 5.0 GPa at the maximum. It was observed that such a high strength alloy was shattered after the transverse rupture strength test and so that it was difficult to detect the fracture origin. Based on the limiting strength that is generated in normal-grained cemented carbide, it was considered that a high strength level exceeding the limiting strength of normal-grained alloy was achieved in the ultrafine-grained cemented carbide obtained in this study. The WC-Co ultrafine-grained cemented carbide with Ti(C,N)-Cr3C2 was superior in strength compared to conventional cemented carbide. New applications can be expected to take advantage of these characteristics. [ABSTRACT FROM AUTHOR]

High-strength and high-electrical-conductivity hypoeutectic Cu-Zr alloys have been developed. The authors succeeded in balancing characteristics well in a wide range of mechanical strength and electrical conductivity by using dispersion strengthening and fiber reinforcing techniques in nano scale. These have been put to practical use by first processing hypoeutectic Cu-Zr alloy cast-material into ultra-fine wires, and are applied to various cable and wire-electrode applications. In contrast, SPS (Spark Plasma Sintering) material using commercially available powders as a raw material is in practical use as a bulk material. The history of development of hypoeutectic Cu-Zr alloys from their alloy design, their manufacturing process, and the development of eutectic/hypereutectic Cu-Zr alloy SPS material are shown in this paper. [ABSTRACT FROM AUTHOR]

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