direct metal laser sintering(dmls)
TRANSCRIPT
Introduction:
What is Rapid Prototyping ?
Rapid prototyping is a group of techniques used to quickly
fabricate a scale model of a physical part or assembly using three-
dimensional computer aided design (CAD) data.
Fig-1 CAD Model Fig-2 Finished Part
History
The roots of Rapid Prototyping can be traced to Topography &
Photo sculpture
Topography was first proposed by Blanther in 1890.
Photo sculpture for 3D replicas of objects were proposed by Bogart
in 1969.
Fig-3: Topography Fig-4: Photo sculpture 3D
Fundamentals of Rapid Prototyping
RP techniques employ the some basic five-step process
1.Creating the 3D CAD model of the design
2.Converting the CAD model into STL format (stereo lithography)
3.Slicing the STL file into thin cross-sectional layers
4.Constructing the model one layer atop another
5.Cleaning and finishing the model
1. 2.
3. 4.
5.
Fig-5: Basic Steps in RP Technology
Classification of RP Systems
1. Liquid-Based
2. Solid-Based
3. Powder-Based
Direct Metal Laser Sintering (DMLS)
Direct metal laser sintering (DMLS) Is an additive
manufacturing technique that uses a laser as the power source to
sinter powdered material (typically metal), aiming the laser
automatically at points in space defined by a 3D model, binding
the material together to create a solid structure.
Working principle:
Fig-6: Step by step procedure of DMLS
Metal Powders used
Stainless steel 17-4
Aluminum
Titanium Ti-64
Nickel alloy IW 718
Advantages of DMLS
High speed: Because, no special tooling is required, parts can be
built in a matter of hours.
Complex geometries: Components can be designed with internal
features and passages that cannot be cast or otherwise machined.
High quality: DMLS creates parts with high accuracy and detailed
resolution.
Medical field
Application Aerospace Industries
Manufacturing Automotive
Limitations
Surfaces need to be polished.
Removing metal support structures and thermal post-processing is time
consuming (you can’t have the supports in a different material than the
part)
Case Study Titanium glasses using metal additive manufacturing
Fig-7: Titanium glasses
The eye venture decided to look into the possibility of using additive
manufacturing in titanium as this eliminated the need for tooling and also
allowed flexibility in future interchangeable designs of the frame can be made by
CAD data and the parts rebuilt quickly and cost effectively.
Conclusion
The DMLS uses high intensity laser source and imparts the energy over the metal powder as per the
required geometry pattern ,melts below it’s melting point and solidifies the metal powder to the
deposited layer without affecting the material properties.
DMLS process used for the actual material needed to make the part at one build time, there by
eliminates the secondary machining.
DMLS eliminates tool change & production line cost resulting in small batch & single part build cost
efficiency.
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