Materials Science Forum Vol. 723

Abstract: Electromagnetic stirring (EMS) is an important method to homogenize the hard phase of the cladding layer. Rotary Permanent magnet electromagnetic stirring (PEMS) is adopted during the experiment. The changes of heat affected zone, solidification character, microstructure and hardness of TA15 Laser Metal Deposition (LMD) based on PEMS have been researched during the experiment. The results show that the PEMS can refine the grain, homogenize the microstructure, eliminate the disfigurement and enhance the hardness.

Abstract: Drilling and cutting experiments in magnesium alloy sheet were conducted using water-jet guided laser. Morphology characteristics in processing areas were analyzed and compared with that of the conventional laser processing. The results show the processing areas are clean, with almost no molten residues attached and negligible heat damage in water-jet guided laser processing. The hole walls and cut surfaces are smooth and have some degree of slope, and are completely covered with dense protruding particles at microcosmic scale. However, with conventional laser, the processed areas are attached with a large number of residues, and obvious secondary solidified layers.

Abstract: The carbide drills with different edge preparation were used for drilling of 40Cr. The influence of drilling speed and amount of feed on drilling forces has been studied by the single factor experiment. The conclusions indicated: when the feed went bigger, the drilling forces of the polished drills were lesser than unpolished drills for un-coating drills; but for coating drills, the drilling forces of the polished drills were greater than unpolished drills. With the increase of cutting speed, drilling forces of un-coating drills mounted up first but went down afterward; and the drilling forces of coating drills increased monotonously.