Powder Bed Fusion Beam Scanning to Prevent Adjacent-Line Heat Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In three-dimensional powder bed fusion additive manufacturing, the melt pool formed by metal in one line is often disturbed by heat from the next line during beam scanning, leading to defects in the shaped object, especially when the line length is short and the time interval between scans is shortened.
Innovation Solution
A three-dimensional PBF-AM apparatus and method that includes performing dummy scanning between the end of beam scanning on one line and the start of the next line, using a beam irradiation device to scan in a state that does not cause melting of the powder material, thereby reducing heat transfer and preventing metal from being affected by the next line's scanning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If beam scanning is performed sequentially on multiple lines to melt powder material, then the shaped object can be formed by laminating coagulated layers, but the melt pool formed by metal in one line is disturbed by heat from the next line, causing defects in the shaped object
Solution Approach 1:
The patent applies preliminary action by performing dummy scanning before the actual beam scanning on each line. This dummy scanning pre-heats the powder material in a controlled manner, creating a thermal buffer that prevents the melt pool from being disturbed by subsequent heating from the next line. The dummy scanning is performed at a lower power level to avoid melting while still providing thermal preparation.
Solution Approach 2:
The patent introduces an intermediary process (dummy scanning) between the beam scanning of adjacent lines. This intermediary action serves as a thermal mediator that manages the heat transfer between lines, preventing direct thermal interference that would otherwise disturb the melt pool and cause defects.
2Speed
If the line length is short, then the beam scanning process is faster, but the time interval from the start of beam scanning of the M-th line to the start of beam scanning of the (M + 1)th line is shortened, making the line easily affected by heat of the next line
Solution Approach 1:
For short lines where the time interval is naturally short, the patent applies preliminary action by performing dummy scanning that extends the effective time interval between lines. The dummy scanning creates a thermal buffer zone that compensates for the reduced time interval, preventing heat interference from the next line even when lines are short and scanned quickly.
Solution Approach 2:
The patent changes the scanning parameters by introducing dummy scanning with different power levels and durations. For short lines, the dummy scanning parameters are adjusted to provide sufficient thermal buffer without excessive heating, thereby managing the heat interference issue specific to short line lengths while maintaining high scanning speeds.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively prevents metal in one line from being affected by heat during the scanning of the next line, reducing the likelihood of defects in the final object by maintaining a longer time interval and adjusting scanning conditions to minimize thermal impact.
Implementation Method 1
a beam irradiation device which irradiates the powder material spread on the build plate with a beam
Implementation Method 2
melt the powder material in the build region line by line
Implementation Method 3
performs dummy scanning to scan the beam in a state that does not cause melting of the powder material
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a technique capable of preventing metal to be melted in one line from being affected by heat at the time of performing beam scanning on the next line. A three-dimensional PBF-AM apparatus (10) includes: a build plate (22) on which a powder material (32) is spread in layers; and a beam irradiation device (14) which irradiates the powder material (32) spread on the build plate (22) with a beam (15). The beam irradiation device (14) divides a build region (39) of the powder material (32) spread on the build plate (22) into a plurality of lines and performs beam scanning to melt the powder material (32) in the build region (39) line by line, and performs dummy scanning to scan the beam (15) in a state that does not cause melting of the powder material (32) between an end of beam scanning of an M-th (M is a natural number) line and a start of beam scanning of an (M + 1)th line.