Additive Manufacturing Surface Smoothing via Binder Softening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Additively manufactured metal components often exhibit rough, stepped surfaces due to the layer-by-layer printing process, which can lead to cracking and undesirable notch effects, posing challenges for applications requiring smooth surfaces.
Innovation Solution
A method involving the application of a chemical to soften the binder material on the surface of additively manufactured parts, allowing powder particles to flow into recesses under gravity, followed by thermal treatment to vaporize and remove the binder, thereby smoothing the surface and fusing the powder particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If FFF/FDM layer-by-layer printing process is used to manufacture metal parts, then additive manufacturing capability is achieved, but surface roughness increases and stepped surfaces are formed
Solution Approach 1:
The patent applies binder softening treatment before final sintering to pre-smooth the stepped surface. By softening the binder material that holds powder particles, the powder can flow into recesses and fill stepped areas, creating a smoother surface prior to sintering. This preliminary action prevents the formation of severe notches and improves surface finish before the final manufacturing step.
2Manufacturing precision
If chemical is applied to soften binder material for surface smoothing, then surface roughness is reduced, but chemical removal and additional processing steps are required
Solution Approach 1:
The patent combines the binder softening step with the subsequent sintering process. The chemical is applied to soften the binder, allowing surface smoothing, and then the same thermal processing step (sintering) that follows removes the chemical and binder material simultaneously. This merging of functions reduces the need for separate chemical removal steps and integrates multiple purposes into unified process steps.
3Manufacturing precision
If powder particles are allowed to flow into recesses to smooth surface, then surface roughness is reduced, but binder material must be softened which requires chemical application
Solution Approach 1:
The patent changes the physical-chemical parameters of the binder material by applying chemicals that soften the binder. This parameter change (from rigid to soft state) enables the powder particles to flow and rearrange themselves into a smoother configuration. The chemical treatment temporarily alters the binder's properties to facilitate surface smoothing, then the binder is removed or cured after the desired shape is achieved.
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 method effectively reduces surface roughness, minimizes notch effects, and enhances the appearance and durability of additively manufactured metal parts by creating a smoother outer surface, suitable for applications where roughness could lead to fatigue or bacterial growth.
Implementation Method 1
applying a chemical to a stepped surface of an additively manufactured part to at least soften a binder material supporting unprocessed powder particles of the part
Implementation Method 2
allowing the powder particles at the surface to flow under the influence of gravity into recesses defined by the stepped surface
Implementation Method 3
applying comprises vaporising the chemical and condensing the chemical on to the surface of the part
Implementation Method 4
condensing comprises creating an energy potential between the part and the vaporised chemical
Implementation Method 5
thermally treating comprises vaporising the binder material
Implementation Method 6
During thermal post-processing, the metallic powder sinters together to form the final part whilst any remaining binder material is vaporised
Implementation Method 7
sintering the part to fuse the powder particles together
Data Source
AI summary
According to the present disclosure, there is provided a method for smoothing a surface of an additively manufactured metal part. The method comprises applying a chemical to a stepped surface of an additively manufactured part to at least soften a binder material supporting unprocessed powder particles of the part and allowing the powder particles at the surface to flow under the influence of gravity into recesses defined by the stepped surface to thereby reduce a roughness of the surface. Advantageously, it has been found that the afore-described method is able to provide a part having an improved surface smoothness.