Abstract：SLM alloying technology is a method in which the pure element powder blend is alloyed directly and high density samples are formed synchronously in the process of laser selective melting (SLM). This technology can save the pre-alloying process of raw material powder and achieve high-throughput bulk sample preparation by real-time and quantitative powder mixed feeding control. Researchers can obtain material data of composition, structure, properties effectively with the combined SLM alloying and high throughput synthesis technology. The development of new material such as high entropy alloys and other novel materials can be promoted effectively once the technology is available, hence, there are both great scientific significance and application value. Based on the self-designed SLM high-throughput preparation system, 12 groups of Fe-Ni alloy bulk samples were prepared by real-time quantitative mixing of iron and nickel elemental powders and SLM printing in present work. The density and phase transition of homogeneous Fe-Ni alloy were calculated by CALPHAD method. The powder mixing accuracy of the equipment and the molding performance of the sample were analyzed by metallographic scanning, energy spectrum, XRD and microhardness test. The calculation and experimental results show that the mixing accuracy of powder composition based on self-developed high-throughput SLM equipment can be controlled within 6 % ( mass percentage ). When the forming process was 111J/mm3, the forming properties of all samples were good and the relative density were above 98.5 %. There were no obvious holes and no fusion in the microstructure. The micro-zone alloying of all samples was basically completed during SLM printing. The hardness of mixed powder samples varied from 150 HV to 330 HV, and there was no obvious discrete distribution of hardness caused by equipment instability.
2021, Vol. 28 