Additive Manufacturing Powder Bed with Bonding Agent
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Solution Overview
Problem
Existing additive manufacturing processes, such as DMLM and binder jetting, are time-consuming and result in green compacts with limited strength and durability, requiring careful handling and multiple heating steps, which complicates the manufacturing process.
Innovation Solution
A system and method involving a powder bed formed from a mixture of a build material and a thermally activated bonding agent, where the powder bed is selectively heated to partially sinter the build material, maintaining it in a solid state, and then further sintered in an oven to form a compact object with enhanced strength and durability, using a lower energy input due to the bonding agent's lower melting point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If binder jetting is used to manufacture objects, then the process can operate at lower energy input, but the resulting green compact has limited strength and durability requiring careful handling
Solution Approach 1:
A binding agent is introduced as an intermediary substance mixed with the powder material. This binding agent contains organic material that, when heated, carbonizes to form a carbon-rich layer facilitating metallurgical bonding between metal particles, thereby strengthening the green compact without requiring high energy input during the additive manufacturing process
Solution Approach 2:
The process changes the chemical composition parameters of the powder bed by incorporating organic binding agents. Subsequent thermal processing transforms these organic materials into carbon-rich layers that enable strong metallurgical bonds, effectively changing the material properties from weak green compact to strong sintered part
2Strength
If DMLM is used to manufacture objects, then objects with high strength can be produced, but the process is time-consuming and has limited productivity
Solution Approach 1:
Instead of fully melting the metal powder as in DMLM, the process applies partial heating that activates the binding agent and initiates sintering. This partial action approach achieves sufficient bonding strength while significantly reducing processing time and increasing productivity
Solution Approach 2:
The binding agent is pre-mixed into the powder material before manufacturing. This preliminary preparation enables the material to self-bond during thermal processing, eliminating the need for high-energy real-time melting and acceleration the manufacturing process
3Strength
If multiple heating steps are performed to remove adhesive and solidify green compact, then the object achieves final strength, but the process complexity increases
Solution Approach 1:
Multiple separate heating steps (adhesive removal, densification, sintering) are merged into a single integrated thermal processing step. The binding agent formulation and heating profile are designed to accomplish multiple objectives simultaneously, simplifying the process while maintaining final object strength
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 enables high-speed manufacturing of compact objects with increased durability and strength, reduces the need for post-processing steps, and allows for vigorous depowdering techniques, resulting in chemically inert and metallurgical bonds.
Implementation Method 1
selectively heating the powder bed to a temperature such that the build material is at least partially sintered together to form a compact object
Implementation Method 2
the bonding agent has a lower melting point than the build material
Implementation Method 3
selectively heating the powder bed to a temperature such that the build material is at least partially sintered together by the bonding agent
Data Source
AI summary
A system for use in additively manufacturing an object. The system includes a powder bed configured for containment within a build chamber, wherein the powder bed is formed from a mixture of a build material and a bonding agent. The system also includes a heat source configured to selectively heat the powder bed to a temperature such that the build material is at least partially sintered together by the bonding agent. The heat source also selectively heats the powder bed to the temperature that maintains the build material in a solid state.