ASTM E1920-03 (2021) PDF

Full title and description

Standard Guide for Metallographic Preparation of Thermal Sprayed Coatings — ASTM E1920‑03(2021). This guide provides recommended practices for sectioning, cleaning, mounting, grinding, polishing, and related specimen preparation techniques used to reveal and evaluate the microstructural features of thermal sprayed coatings and their substrates for optical metallographic examination.

Abstract

ASTM E1920‑03(2021) is a short, practice‑style guide that consolidates recommended metallographic specimen preparation methods tailored to thermal spray coatings (including plasma spray, HVOF, flame spray, and similar processes). It emphasizes specimen selection and preparation sequences that minimize preparation artifacts and preserve features such as splats, porosity, interfacial continuity, and unmelted particles so that meaningful microscopic evaluation and failure analysis can be performed.

General information

• Status: Active (reapproved / reissued edition).
• Publication date: January 9, 2021 (reapproval of E1920‑03).
• Publisher: ASTM International.
• ICS / categories: 25.220.20 (Surface treatment / coating processes).
• Edition / version: E1920‑03(2021) — original designation E1920‑03, reapproved 2021.
• Number of pages: 5 pages.

Scope

This guide covers recommendations for sectioning, cleaning, mounting, grinding, polishing, and final presentation of thermal sprayed coating specimens and the substrates to which they are applied so as to reveal microstructural features for microscopic examination. It is intended to provide consistent and reproducible specimen preparation methods across a variety of coating/substrate combinations and equipment, and it refers users to general metallographic preparation practice (for example Practice E3) for broader techniques. The guide does not attempt to address every specific safety or regulatory requirement; users are responsible for applying appropriate safety practices.

Key topics and requirements

• Specimen selection — representative sampling, orientation (polish plane normal to coating thickness), and size constraints.
• Sectioning techniques to minimize damage to the coating/substrate and interface (mechanical cutting, abrasive methods, best practices for through‑thickness sections).
• Cleaning and degreasing to remove loose debris without altering coating microstructure.
• Mounting approaches (resin selection and curing) appropriate for porous/hard coatings and for preserving edges and interfaces.
• Grinding and polishing sequences tailored to mixed‑hardness coating/substrate systems to avoid pull‑out, smearing, or formation of false porosity.
• Recommended observations and features to reveal: splat morphology, porosity distribution, unmelted particles, linear detachment, bond coat/top coat thickness, interfacial contamination.
• Notes on etching, optical contrast enhancement, and documentation of preparation parameters for reproducibility and reporting.

Typical use and users

This guide is used by metallographers, coating researchers, failure analysis laboratories, quality and inspection engineers, contract coating producers, and testing laboratories that perform microscopic evaluation of thermal sprayed coatings. Typical applications include production quality control, coating development and R&D, root‑cause failure analysis, and acceptance testing where microstructure, porosity, bond integrity, and coating thickness must be assessed.

Related standards

Commonly used alongside ASTM Practice E3 (Preparation of Metallographic Specimens) and ASTM E2109 (Test Methods for Determining Area Percentage Porosity in Thermal Sprayed Coatings). It is issued under the jurisdiction of ASTM Committee E04 (Metallography) and its subcommittees that handle specimen preparation and related practices.

Keywords

thermal spray, thermal sprayed coatings, metallography, specimen preparation, polishing, sectioning, plasma spray, HVOF, flame spray, porosity, splat, bond coat, ASTM E1920.

FAQ

Q: What is this standard?

A: ASTM E1920‑03(2021) is a guide that provides recommended metallographic specimen preparation procedures specifically for thermal sprayed coatings and their substrates to enable reliable microscopic examination.

Q: What does it cover?

A: It covers specimen selection, sectioning, cleaning, mounting, grinding, polishing, and preparative notes that help reveal coating microstructure (including porosity, unmelted particles, splat structure, and interfacial condition) for optical microscopy.

Q: Who typically uses it?

A: Metallographers, materials engineers, coating producers, independent testing laboratories, and failure analysis teams use this guide during R&D, production QC, and forensic examinations of thermal spray coatings.

Q: Is it current or superseded?

A: This designation, E1920‑03, was reapproved and issued as E1920‑03(2021). As of the reapproval date (January 9, 2021) it is the current guide; users should check with ASTM International for any later revisions or superseding documents.

Q: Is it part of a series?

A: It is part of the ASTM metallography and coatings practice family overseen by Committee E04 and is intended to be used in conjunction with general specimen preparation Practice E3 and other coatings test methods such as E2109.

Q: What are the key keywords?

A: Thermal spray, metallography, specimen preparation, polishing, sectioning, porosity, HVOF, plasma spray, splat, bond interface.