Metal powder bed additive manufacturing method for refining grains

Abstract

The invention relates to a metal powder bed additive manufacturing method for refining grains. The metal powder bed additive manufacturing method comprises the steps of constructing a three-dimensional model of a to-be-machined workpiece; slicing the three-dimensional model, and planning a scanning path according to slicing layer data; preheating a powder bed forming bottom plate before powder paving; paving metal powder on the preheated powder bed forming bottom plate, and preheating a metal powder forming area; enabling the preheated metal powder to be subjected to selective melting scanning according to scanning paths, wherein the first scanning path and the second scanning path are characterized in that a plurality of first scanning straight lines and a plurality of second scanning straight lines are started to be scanned in sequence in the first direction, and after scanning is started, after the first scanning straight lines are scanned for delta t time each time, the second scanning straight lines need to be scanned for delta t until single-layer entity slice layers are obtained after scanning is completed; and repeating the preheating process before powder paving, the powder paving process, the preheating process after powder paving and the selective melting scanning process till the single-layer solid sheet layers are stacked layer by layer, and obtaining a target workpiece.

Description

technical field [0001] The invention relates to the technical field of additive manufacturing, in particular to a metal powder bed additive manufacturing method for refining crystal grains. Background technique [0002] Metal powder bed additive manufacturing technology is a technology with short cycle, less process, low cost and net shape. Its formed components have excellent mechanical properties and have great scientific research value and economic benefits. Its application range is quite wide, especially for refractory and difficult-to-process materials, including titanium alloys, titanium-based intermetallic compounds, stainless steel, cobalt-chromium alloys, nickel alloys, etc., and its products can achieve high complexity and high mechanical properties. With the continuous development of metal powder bed additive manufacturing technology, more and more metal materials are added to the field of additive manufacturing printing. For example, in the nuclear industry, zirc...

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Problems solved by technology

[0003] This development is bound to bring new problems to a certain extent. For example, due to the applicability of new materials and the application of additive manufacturing technology, and the poor matching of additive manufacturing technology, the use of additive manufacturing technology has coarse grains and poor fusion. Uniformity, porosity, etc.

[0004] Traditional grain refinement methods mainly use heat treatment, adding nucleating agents, multiple rolling, vibration treatment, etc. However, due to the complexity, diversity, and internal structure of metal biological implants or new-generation nuclear structural The variability of the structure and the high requirements of the structure and performance have limited the traditional forging preparation process of metal structural parts, and the cost has also increased significantly.

And due to the flammability and explosion of some metals such as zirconium powder itself, the risk of powder metallurgy processing is relatively high, forming a safety hazard

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