Laser metal deposition of steel components using machining waste as build material
Gas atomised metal powders are generally used in laser cladding. However, costly new powders prompt the use of machining swarf as an alternative build material. This paper reports on this investigation and establishes its feasibility.
Fundamentals of Solidification
SOLIDIFICATION PROCESSING is one of the oldest manufacturing processes as it is the principal component of metal casting processing. While solidification science evolved from the need to better understand and further develop casting processes, in 2004 solidification science is at the base of many new developments that fall out of the realm of traditional metal casting. Solidification is, strictly speaking, the transformation of liquid matter into solid matter. The microstructure that results from solidification may be the final one, in which case it directly affects the mechanical properties of the product. In other cases, heat treatment or other processes may be used after solidification to further modify the solidification microstructure. However, the outcome of this additional processing will be greatly affected by the solidification microstructure.
ROOM- AND HIGH-TEMPERATURE MAGNETIC PROPERTIES OF Sm(CobalFexCu0.088Zr0.025)7.5 (x=0.30) SINTERED MAGNETS
The effect of Fe content on room- and high-temperature magnetic properties of Sm(CobalFexCu0.088Zr0.025)7.5 (x=0-0.30) sintered magnets, prepared by the conventional powder metallurgy method, has been systematically studied. With increasing Fe content, the remanences BT and maximum energy products (BH)max at room temperature gradually increase and reach optimal values of 1.055 T with x=0.27 for BT, and 205 kJ/m3 with x=0.21 for (BH)max, respectively, and then drop sharply with further Fe increase. An excessive addition of Fe (x≥0.24) results in rapid deterioration of permanent magnetic properties due to the formation of a considerable amount of FeCo soft magnetic phase. It was found that the effect of Fe content on high temperature stability is huge. The lower the Fe content, the smaller the temperature coefficient of coercivity. When x=0.07, a temperature coefficient of coercivity of -0.14%/K (293-723 K) can be achieved, as compared with -0.23%/K for x=0.21. BT of 0.725 T, bHc of 517 kA/m, iHc of 764 kA/m, and (BH)max of 95 kJ/m3 at 723 K were obtained, and the B-H demagnetization curve remains a straight line.