Which 3D printing materials are suitable for metallographic analysis?

Metallographic analysis is a versatile quality control method that can be successfully applied to virtually all major categories of 3D printing materials, though preparation techniques and analysis objectives vary significantly between material types.

Metallic Materials - Primary Application

Metallic materials represent the most common and standardized application for metallographic analysis in additive manufacturing.

Titanium Alloys:

• Ti-6Al-4V (Grade 5): Analysis focuses on α+β phase distribution, prior β grain size, and martensitic transformations

• Ti-6Al-4V ELI (Grade 23): Critical for medical implants to verify microstructure against ASTM F3001

• CP-Ti Grades: Examination of grain size and purity for chemical compatibility

Steel and Iron-Based Alloys:

• Stainless Steel:

  • SUS316L: Austenite cell structure and δ-ferrite content

  • 17-4 PH: Precipitation hardening phase distribution

• Carbon Steel:

  • Tool Steels (H13, D2): Carbide distribution and grain boundaries

High-Temperature Alloys:

• Superalloy:

  • Inconel 718: γ' and γ'' precipitation, carbide networks

  • Hastelloy X: Grain boundary chemistry and secondary phases

Aluminum and Copper Alloys:

• Aluminum Alloys:

  • AlSi10Mg: Silicon particle morphology and grain structure

  • Scalmalloy®: Intermetallic precipitation

• Copper:

  • CuCr1Zr: Precipitation hardening and grain size

Ceramic Materials - Specialized Preparation

Ceramic materials require specialized preparation techniques due to their brittleness and hardness.

Ceramic Materials Suitable for Analysis:

• Zirconia (ZrO₂): Phase transformation (tetragonal to monoclinic)

• Alumina (Al₂O₃): Grain size and pore distribution

• Silicon Carbide (SiC): Sintering density and grain boundaries

• Bio-ceramics: Pore interconnectivity in Hydroxyapatite (HA)

Polymer Materials - Unique Challenges

Polymer metallography (more accurately, plastography) necessitates distinct preparation and examination methods.

Plastics and Resins:

• Semi-Crystalline Polymers:

  • Nylon (PA): Spherulite size and distribution

  • PEEK: Crystallinity and fiber orientation

• Amorphous Polymers:

  • ABS: Rubber particle dispersion in SAN matrix

  • PC: Molecular orientation and layer adhesion

• Photopolymers:

  • Conversion degree and filler distribution

  • Layer bonding and curing completeness

Material-Specific Preparation Considerations

Metals:

• Etchants: Kroll's (Ti), Marble's (stainless), Keller's (Al)

• Mounting: Conductive mounts for SEM examination

• Polishing: Diamond suspensions to 0.25μm

Ceramics:

• Sectioning: Diamond wafering blades with coolant

• Polishing: Diamond compounds with chemical-mechanical final polish

• Etching: Thermal or chemical for grain boundaries

Polymers:

• Sectioning: Low-speed saws to prevent deformation

• Mounting: Cold mounting to avoid thermal stress

• Staining: Often required for contrast in amorphous materials

Industry Application Examples

Aerospace and Aviation:

• Titanium and nickel alloy microstructure certification

• Porosity control in critical rotating components

Medical and Healthcare:

• Implant material biocompatibility verification

• Porous structure analysis for bone ingrowth

Automotive:

• Aluminum alloy heat treatment validation

• Tool steel wear resistance microstructure

Witness Coupon Strategy

For all critical applications, we recommend building dedicated witness coupons using identical:

• Material batch

• Process parameters

• Build orientation

• Post-processing (including Heat Treatment and Hot Isostatic Pressing)

This approach allows comprehensive metallographic analysis without compromising functional components, ensuring quality control across all 3D Printing Services while maintaining the integrity of production parts.