Molybdenum crucible was prepared by 3D printing technology
3D printing (or "additive manufacturing") is a process that combines materials layer by layer, based on a three-dimensional digital model, as opposed to the traditional process of material removal. Compared with traditional material cutting and forced forming methods,3D printing uses point-by-point or layer-by-layer materials to create physical models. Its forming principle has the following:
1) melting extrusion and accumulation forming. Use hot melt and adhesion of thermoplastic material, the material wire through the heater extrusion head melted into liquid, extrusion head under the control of computer, moving along the designed parts contour section extrusion melt materials silk at the same time, the material in a short time, solidification, forming a layer, then squeeze head axial movement, build the second floor, cascading into parts.
(2) light curing photosensitive resin forming. The liquid photosensitive resin is scanned by UV laser point by point, and the scanned area is polymerized and cured. Then a new layer of liquid resin is placed on the cured surface and scanned, and the parts are manufactured layer by layer repeatedly.
(3) selective laser sintering. Powder materials, such as plastic powder, mixed powder of ceramic and binder, mixed powder of metal and binder, etc., are selectively sintered in layers according to the contour of parts by laser beam.
(4) Layered entity manufacturing method. The material is made into thin sheet material, and the contour of this layer of parts is cut out with CO2 laser, and then the second layer of thin sheet is bonded. The contour of this layer of parts is cut out with laser again, and the process is repeated to complete the manufacturing of parts.
According to the principle of 3D printing technology, the idea of preparing molybdenum crucible with this method can be realized. Selective laser sintering method is adopted. The mixed powder of molybdenum and binder prepared is sintered in layers according to the crucible size with CO2 laser, and finally the crucible is formed into a crucible. The advantages of using 3D printing technology to produce molybdenum crucible are as follows: ①3D printing, as an additive process for the preparation of parts, is incomparable to any existing processing methods for the utilization of raw materials, cost saving. ②Compared with the process of sintering and rolling molybdenum slabs for rotary pressing molybdenum crucible, 3D printing technology directly uses metal powder, which has simple process and saves time.
Although in principle, it is feasible to produce molybdenum crucible by 3D printing technology, but there are some technical difficulties. First of all, the high melting point and strength of molybdenum, and the selection of binder in the sintering process, is a big difficulty for the whole process. Secondly, for the parts that have been produced by 3D printing technology, the dimensional accuracy still needs to be strengthened. When producing molybdenum crucible with 3D printing technology, how to improve its dimensional accuracy is another difficulty. In addition, how to ensure the strength of the molybdenum crucible and how to avoid the bubbles caused by the evaporation and ablation of binder in the sintering process are also the technical difficulties to be considered.
