A powder-removing method for three-dimensional printing of thin-walled porous metal blanks by 3dp method

Abstract

The invention relates to the technical field of porous metal material and 3D printing, in particular to a powder removal method of a 3DP printed thin-walled porous metal blank. The method comprises the following steps of firstly, selecting metal powder required for molding, spraying a bonding agent to the metal powder and manufacturing a printing blank through the 3DP method; secondly, putting theprinting blank to be subjected to powder removal in a drying box to be heated for 1-2 h and then putting the printing blank into an ultrasonic cleaning machine containing an anhydrous ethanol solution to conduct ultrasonic powder removal; and thirdly, putting the printing blank subjected to powder removal into the drying box again to conduct heating treatment and then obtain the thin-walled porous metal blank with the structural integrity. Through the powder removal method, the powder of the porous printing blank with the low strength can be removed. The powder removal method has the characteristics that powder removal operation is easy, the cost is low, and the method is energy-saving and environment-friendly. The method can be adopted to conduct powder removal on 3DP printed thin-walledporous metal blanks in batch, can achieve the powder removal mechanization and provides a guarantee for mass production of 3DP parts.

Description

technical field [0001] The invention relates to the technical field of porous metal materials and 3D printing, in particular to a powder removal method for three-dimensional printing of thin-walled porous metal blanks by 3DP method. Background technique [0002] At present, 3D printing technology is developing rapidly, and its application in metal material printing is increasing. In order to further explore the potential of 3D printing technology, it has become a new trend in the application of 3D printing technology to realize lightweight innovative design and prepare porous metal materials in the industry. However, metal 3D printing technologies such as selective laser sintering / melting (SLS / SLM) and inkjet 3D printing (3DP) are based on the method of powder bed stacked printing. After the porous parts are printed, powder removal operations are required, namely At this time, the pores of the porous part are still occupied by unsintered or unbonded powder. This part of the...

AI Technical Summary

Problems solved by technology

However, in the 3DP method, the powder is bonded and formed by spraying a binder. The bonding force between the bonded powders is small, and the strength of the printed blank is low. For thin-walled porous parts, the walls between adjacent pores The thickness is small, so that the strength of the whole porous billet is lower, so it is not suitable to use a mechanical method with a large force for powder removal

On the other hand, although the powder that needs to be removed is not bonded by the binder, they are compacted layer by layer during the powder laying process of 3DP printing, and the blank may be formed when the binder solidifies. Shrinkage produces compressive stress, coupled with the binding forces such as van der Waals force and electrostatic force between the fine powder particles, and the shape factor of the powder also causes the interaction between the powder particles. These reasons make the porous blank printed by 3DP method It is relatively difficult to remove powder, especially when the cross-sectional size of the channel is small and the depth is large

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