DFM DESIGN GUIDE
Seven rules, written before you cut a tool
Ceramic injection molding has its own physics - wall thickness, tolerance, gates, undercuts, surface, curved surfaces, threads. Every rule below exists because someone found the boundary the expensive way.
Wall-Thickness Design
The minimum wall thickness is set by the weakest stage of the process chain - not by the sintered material's final strength.
Open the full page 02 · /dfm/tolerance/Tolerance & Dimensioning
±0.05mm is the output of four conditions being met simultaneously - change any one condition and the achievable precision changes with it.
Open the full page 03 · /dfm/gate-design/Gate Design
Gate location determines flow direction and green-body density. Mold flow simulation can predict possibilities in design, however, the actual results are only known after sintering.
Open the full page 04 · /dfm/undercut/Undercuts & Demolding
Green-body strength at demolding is far below the sintered finished part's - what you think of as "hard ceramic" behaves like a wet sand structure at that moment.
Open the full page 05 · /dfm/surface/Surface-Quality Zoning
A-grade and B-grade faces must be marked on the drawing - cosmetic grade determines gate location, and gate location determines the whole mold design direction.
Open the full page 06 · /dfm/curved-surface/Curved Surfaces & Distortion Control
Curved parts experience both gravity and thermal-gradient effects during sintering - controllable, but only with advance planning.
Open the full page 07 · /dfm/threads/Threads & Fastening
Ceramic can't be tapped after sintering, and molded internal threads have low yield - in most cases, a metal insert is the more sensible answer.
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