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High-frequency induction brazing of cemented carbide (WC–Co, K20) and alloy steel (AISI 4140) using Cu–Zn base filler metal was carried out. The relationship between microstructure and performance of the welding joint was investigated. It was found that the filler metal exhibited excellent wettability and metallurgical bond in the welding surface. As the heating rate reduced, welding joint appeared smooth without any visible crack. In the diffusion layer, some intermetallic compounds were observed, which were produced by the reaction of diffusion atoms. The microhardness in the middle of the welding seam was 168 Hv and it increased gradually when approaching to the edge of welding seam. With brazing temperature increased or heating rate decreased, the shear strength of welding joint increased first and then decreased. The machining test clearly revealed that the cutting temperature and the flank wear increased with the cutting speed rose. The welding joint had good shear strength when the temperature was below 500°C and the shear strength decreased seriously when the temperature exceeded 500°C. [ABSTRACT FROM PUBLISHER]

The effect of rapid solidification of a suction cast specimen on the microstructure, magnetocrystalline anisotropy, and magnetic-field-induced strain of the Co1.36Ni1.21AlFe0.12alloy was investigated. The results show that a dual-phase structure consists of L10-type twin martensite with a small amount of coexisting A1-type divorced eutectic γ phase in the specimen. After rapid solidification, the network divorced eutectic γ phase was smashed to pieces by strong suction force and the grain grew in a preferred orientation. At the same time, the specimen after rapid solidification has high magnetocrystalline anisotropy and excellent shape recovery. The trend of twin martensitic rearrangements was evaluated by the O'Handley model, and a relatively large magnetic-field-induced strain was obtained in the specimen with rapid solidification. [ABSTRACT FROM PUBLISHER]