Additive Manufacturing Laser Irradiation Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Additive layer manufacturing methods using high-temperature polymer materials face challenges in maintaining material properties and efficiency, as prolonged exposure to high temperatures can lead to semi-sintering and waste of unirradiated powder, while existing methods to optimize this result in suboptimal material properties.
Innovation Solution
A method involving controlled temperature management and multiple, spaced irradiations with a laser or particle beam to partially melt polymer layers, ensuring the material reaches the melting temperature only after multiple intervals, with each irradiation providing insufficient energy to heat the material from the glass transition temperature to the melting point, thereby maintaining material properties and allowing reuse of unirradiated powder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the material is maintained at a temperature close to the melting temperature to reduce the energy required for melting, then the manufacturing efficiency is improved, but the material properties deteriorate due to semi-sintering and negative thermal history effects
Solution Approach 1:
The patent divides the irradiation process into multiple separate irradiation steps instead of applying all energy in one step. Each step provides only a portion of the total required energy, and the material is allowed to cool partially between steps. This segmentation prevents excessive thermal accumulation that would cause semi-sintering while still achieving complete melting over time, thus resolving the contradiction between manufacturing efficiency and material property preservation.
Solution Approach 2:
The patent implements periodic irradiation cycles where the material is irradiated, then allowed to cool, then irradiated again. This periodic action with multiple intervals ensures that the material never reaches prolonged exposure to temperatures close to melting point, preventing semi-sintering and maintaining material properties, while still achieving the desired melting effect through cumulative energy input.
2Strength
If the material is maintained at a temperature significantly below the melting temperature to preserve material properties, then the material properties are maintained, but the manufacturing efficiency decreases due to increased energy requirements
Solution Approach 1:
By segmenting the irradiation into multiple steps with cooling intervals, the patent avoids the need to maintain continuously high temperatures. The material is heated to near-melting temperature only temporarily during each irradiation step, then cooled before the next step. This approach preserves material properties while achieving efficient manufacturing through cumulative energy input over multiple cycles.
3Speed
If high energy is applied in a single irradiation step to melt the material quickly, then the manufacturing speed is improved, but the material properties deteriorate due to thermal shock and semi-sintering
Solution Approach 1:
The patent segments the total energy input into multiple smaller irradiation steps rather than applying all energy in one step. This prevents thermal shock and semi-sintering that would occur with single high-energy irradiation, while still achieving rapid manufacturing through the cumulative effect of multiple quick irradiation cycles with brief cooling intervals.
Solution Approach 2:
The periodic irradiation pattern with multiple intervals allows the material to be quickly heated and cooled repeatedly. This periodic action prevents the material from remaining at high temperatures for extended periods, avoiding semi-sintering and thermal shock, while maintaining fast manufacturing speed through efficient energy delivery in multiple short bursts.
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 enhances the material properties and mechanical characteristics of the three-dimensional object, such as strength and ductility, while enabling the reuse of powder material, thus reducing waste and manufacturing costs.
Implementation Method 1
irradiating the layer with at least one laser or particle beam
Implementation Method 2
The laser or particle beam is chosen such that the material at least partially absorbs the energy provided by the laser or particle beam
Implementation Method 3
the material of the respective layer is melted locally in the irradiated portions
Implementation Method 4
the material fuses at said position to the layer thereunder
Implementation Method 5
a glass transition temperature and is preferably thermoplastic... in each of said positions the glass transition temperature is initially reached during the first irradiation
Data Source
Figure 1~2
Figure 3
AI summary
The application relates to a method of manufacturing a three-dimensional object by additive layer manufacturing and to a corresponding apparatus for carrying out the method. The comprises successively providing a plurality of layers of material in powder form, one on top of the other, on a support means. The material in powder form is or comprises polymer material. Prior to providing the subsequent layer, each layer is irradiated with at least one laser beam (13) or particle beam (13) using at least one irradiation device (12), wherein each layer is irradiated selectively only in those portions of the layer corresponding to the three-dimensional object being manufactured and wherein the irradiation is carried out in such a manner that the material is melted locally in the corresponding portions. The temperature of the layers is controlled such that prior to irradiation of each layer the respective layer has a starting temperature which is in a range from the glass transition temperature of the polymer material to 30% above the glass transition temperature. For each layer the irradiation is carried out in such a manner that each location of those portions of the layer corresponding to the three-dimensional object being manufactured is irradiated multiple times during multiple spaced time intervals associated with the respective location. Operating parameters of the at least one irradiation device (12) are chosen such that in each of the locations the polymer material reaches the melting temperature only during or after the second or a subsequent one of the time intervals associated with the respective location and that in each of the locations the energy introduced during each of the associated time intervals by the at least one laser beam (13) or particle beam (13) is insufficient to heat the polymer material from the starting temperature to the melting temperature of the polymer material.