Dip-Coat Binder Solutions for Additive Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional binder solutions for additive manufacturing do not provide sufficient brown strength to the printed parts, leading to distortion and damage during post-printing processes such as debinding and sintering.
Innovation Solution
A dip-coat binder solution containing a metallic precursor that infiltrates the pores of the printed green body, increasing its density and stiffness, comprising greater than 10 wt % and less than 49 wt % of the metallic precursor, along with a thermoplastic polymer and solvent, applied to enhance the brown strength and stiffness of the printed parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional binder solutions are used in binder jet 3D printing, then the printing process can be completed, but the printed part lacks sufficient brown strength leading to distortion and damage during post-printing processes
Solution Approach 1:
The patent modifies the binder solution composition by incorporating metallic precursors (such as metal salts, metal organic compounds, or metallic nanoparticles) alongside thermoplastic polymers. This parameter change in material composition enables the binder to provide both green strength for handling and brown strength for withstanding debinding and sintering processes, resolving the contradiction between printability and post-processing reliability.
Solution Approach 2:
The invention uses composite binder materials combining organic polymers (for green strength and processability) with metallic precursors (for brown strength and final metal formation). This composite approach allows the binder to perform dual functions: maintaining structural integrity during printing and providing strength during thermal processing, thereby eliminating distortion and damage issues.
2Ease of operation
If the binder solution is designed to provide green strength for handling, then the printed part can be transferred and inspected, but it lacks the brown strength necessary for minimizing distortion during debinding and sintering
Solution Approach 1:
The binder solution formulation is changed to include metallic precursors in addition to thermoplastic polymers. This parameter change enables the binder to transition from providing only green strength to providing both green strength (for handling) and brown strength (for withstanding thermal processing), thus resolving the contradiction between ease of operation and strength requirements.
Solution Approach 2:
The modified binder solution performs multiple functions: it acts as a binding agent for green strength during handling, provides structural support during debinding, and contributes to the final metal structure during sintering. This multi-functionality resolves the contradiction by making a single binder system capable of addressing both handling ease and thermal processing strength requirements.
3Strength
If a dip-coat binder solution with metallic precursor is used, then the brown strength and stiffness are improved, but the process complexity increases due to additional dipping and heating steps
Solution Approach 1:
The patent combines the binder application and metallic precursor infiltration into a single dip-coating step, rather than separate processes. The binder solution simultaneously provides binding agents and metallic precursors that infiltrate pores during one immersion event. Subsequent heating serves dual purposes: removing binder and activating metallic precursors. This merging reduces overall process complexity while achieving improved brown strength and stiffness.
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
The solution significantly improves the brown strength and overall stiffness of the printed parts, reducing shrinkage, cracking, and distortion during sintering, and enhances the mechanical integrity of the final consolidated parts.
Implementation Method 1
a metallic precursor that infiltrates the pores of the printed green body part and increases the density of the printed green body part
Implementation Method 2
heating the dip-coated green body part
Implementation Method 3
the binder is jetted onto successive layers of the powder in a build volume, where layers of the powder and the binder adhere to one another to form a 3D object
Data Source
AI summary
A dip-coat binder solution comprises a dip-coat metallic precursor and a dip-coat binder. The dip-coat binder solution has a viscosity greater than or equal to 1 cP and less than or equal to 150 cP. A method of forming a part includes providing a green body part comprising a plurality of layers of print powder and a print binder, dipping the green body part in a dip-coat binder solution, and heating the dip-coated green body part. The dip-coated green body part is heated to form a coated green body part having a metallic precursor coating on an outer surface of the coated green body part. The coated green body part has a strength greater than or equal to 10 MPa.