Manufacturing Process Selection

Decision-Making Factors in Manufacturing Processes

• When deciding on a manufacturing process, aspects of quality (accuracy, surface), quantities, quantity performance, and costs must be considered.
• The final contour generation and near-net-shape production feasibility are crucial in this decision.

Manufacturing Technology and Processes

• Manufacturing technology offers a wide range of processes (DIN 8580, 2003) that work with different boundary conditions and results.
• These processes can be evaluated based on quality, quantity performance, and cost criteria.

Costs in Manufacturing Processes

• Costs include one-time costs (e.g., setup procedures, jigs, workpiece holders, and tools) and production costs per piece.
• One-time costs are generally low in additive manufacturing processes due to the use of CAD data and software.
• Additive processes typically incur low-to-no cost for jigs, tools, workpiece holders, etc.

Additive Manufacturing Processes

• Additive manufacturing processes involve layer-upon-layer construction to create the final contour.
• Production times are often long due to the layer-by-layer construction process.
• Additive manufacturing processes belong to the "creating cohesion" group (DIN 8580, 2003).

Basic Principle of Additive Manufacturing

• The component is built up successively by creating cohesion layer-upon-layer to give the final contour.
• This is in contrast to conventional manufacturing processes (subtractive manufacturing processes) where the final contour is created by subtraction.

History of Additive Manufacturing

• Additive manufacturing processes were only developed recently, with the first patent in 1986 by Charles W. Hull.
• The patented process is stereolithography, which involves selectively coating a liquid plastic with a laser beam to form a solid layer.

Stereolithography Process

• The process involves the surface of a liquid plastic being selectively coated zone by zone with a laser beam.
• The plastic is locally heated and crosslinked, forming a solid layer upon layer.
• The data required for geometric control of the laser's movement comes from the CAD dataset for the component.