An Integrated Dual Ultrasonic Selective Powder Dispensing Platform for Three-Dimensional Printing of Multiple Material Metal/Glass Objects in Selective Laser Melting

In this paper, we present a new approach of combining point-by-point selective powder delivery with powder bed fusion for multiple material (metal/glass) components printing. Dual ultrasonic vibration was used to achieve stable flowrates of both 316 L steel and soda-lime glass powders which were dispensed selectively and separately. The effects of the stand-off distance and the scanning speeds on the quality of the formed layers were investigated. The results showed that the ratio between the stand-off distance and the powder size (h/d) should be lower than 3 for accurate selective material deposition. However, in practical processing, for preventing the nozzle from being damaged by the parts, the stand-off distance was larger than three times of the powder size. Different laser processing parameters were developed for processing the metal and glass due to material property differences. The interfaces between 316 L and soda-lime glass were examined. A number of 3D objects consisting of metal and glass were printed using this method.