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arxiv: 2605.28852 · v1 · pith:SB7DOJD7new · submitted 2026-05-16 · ⚛️ physics.app-ph · cond-mat.mtrl-sci

Towards standardisation of average grain size measurement of additively manufactured microstructures using EBSD

Vivian Tong , Hannah Zhang , Jacopo Del Gaudio , Ken Mingard , Ali Gholinia This is my paper

Pith reviewed 2026-06-30 19:21 UTC · model grok-4.3

classification ⚛️ physics.app-ph cond-mat.mtrl-sci
keywords additively manufacturedEBSDgrain sizemicrostructurestandardisationNi alloysAl alloysinterlaboratory comparison
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The pith

Recommendations are proposed for a new EBSD-based standard to measure average grain size in additively manufactured materials.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

Additively manufactured alloys feature heterogeneous microstructures with broad grain size distributions and anisotropic or non-convex grain shapes, and no existing EBSD standard fits these traits. An interlaboratory comparison study had multiple participants measure average grain size from one shared EBSD map to identify current practices. From the outcomes of that study, specific recommendations are developed and tested for a new standard suited to AM materials. The work shows the proposal's performance and limits when applied to several different Ni and Al AM components.

Core claim

Based on an interlaboratory comparison of grain size measurements from the same EBSD dataset, the paper proposes recommendations for a new standard to measure average grain size in AM materials and demonstrates the suitability and limitations of that proposal across several Ni and Al AM components.

What carries the argument

The interlaboratory comparison study on a shared EBSD map dataset that identifies used grain size metrics and summary statistics and informs the new recommendations.

Load-bearing premise

The interlaboratory comparison study supplies enough representative data to support recommendations that handle the broad grain distributions and anisotropic shapes typical of AM microstructures.

What would settle it

A new interlaboratory round using a broader set of AM EBSD maps that produces different preferred metrics or summary statistics would show the current recommendations do not generalize.

read the original abstract

Additively manufactured (AM) alloys have heterogeneous microstructures with broad grain size distributions and highly anisotropic and/or non-convex grain shapes. AM components can have complex geometries and porosity which may affect the local microstructure. Currently there is no electron backscatter diffraction (EBSD)-based grain size measurement standard suitable for typical AM materials. An interlaboratory comparison study was conducted to find out what grain size metrics and summary statistics are currently used to describe average grain size. Participants were asked to measure and report the average grain size from the same EBSD map dataset. Detailed reports have been published in Reference [1]. Based on these results, we have tested and propose recommendations for a new standard for measuring average grain size in AM materials. The present work demonstrates the suitability and limitations of the proposal across several different Ni and Al AM components.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript reports on an interlaboratory comparison study in which participants measured average grain size from the same EBSD map of an additively manufactured material. Based on observed practices and results from that study (detailed in Ref. [1]), the authors propose recommendations for a new EBSD-based standard for average grain size measurement in AM materials. The work then tests the proposal on several Ni and Al AM components to demonstrate suitability and limitations for microstructures with broad grain-size distributions and anisotropic/non-convex grains.

Significance. If the recommendations prove robust, they would address a genuine gap: no current EBSD standard adequately handles the heterogeneous, anisotropic microstructures typical of AM. The interlaboratory design is a positive feature for surfacing practical variability. However, the absence of quantitative results, error analysis, or explicit validation metrics in the manuscript makes it impossible to judge whether the proposal actually improves stability or generality under AM-specific challenges.

major comments (2)
  1. [Abstract] Abstract: the central claim that 'we have tested and propose recommendations' and that the work 'demonstrates the suitability and limitations of the proposal across several different Ni and Al AM components' is unsupported by any numerical results, fitted parameters, stability metrics, or error analysis; without these data the load-bearing assertion cannot be evaluated.
  2. [Abstract] Abstract / interlaboratory description: the study rests on a single shared EBSD map plus an unspecified number of additional Ni/Al components; it is not shown that these datasets adequately sample the broad grain-size distributions, highly anisotropic/non-convex grain shapes, complex geometries, or porosity regimes highlighted as AM-specific challenges, leaving the generality of the proposed standard unproven.
minor comments (1)
  1. [Abstract] The manuscript should be made self-contained by summarizing the key quantitative outcomes (e.g., convergence statistics, chosen metrics, and their variability) from Ref. [1] rather than relying solely on the external reference.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive comments. We address each major comment point by point below, indicating where revisions to the manuscript will be made.

read point-by-point responses

  1. Referee: [Abstract] Abstract: the central claim that 'we have tested and propose recommendations' and that the work 'demonstrates the suitability and limitations of the proposal across several different Ni and Al AM components' is unsupported by any numerical results, fitted parameters, stability metrics, or error analysis; without these data the load-bearing assertion cannot be evaluated.

    Authors: The quantitative results from the interlaboratory comparison, including variability in participant measurements and the basis for the recommendations, are fully detailed in Reference [1]. The current manuscript applies the derived recommendations to several additional Ni and Al AM components and discusses observed suitability and limitations based on those applications. We agree that the abstract would be strengthened by explicit mention of key metrics from [1] and any supporting observations from the present work. We will revise the abstract to better anchor the claims in the available data. revision: partial

  2. Referee: [Abstract] Abstract / interlaboratory description: the study rests on a single shared EBSD map plus an unspecified number of additional Ni/Al components; it is not shown that these datasets adequately sample the broad grain-size distributions, highly anisotropic/non-convex grain shapes, complex geometries, or porosity regimes highlighted as AM-specific challenges, leaving the generality of the proposed standard unproven.

    Authors: The interlaboratory study was intentionally based on one shared EBSD map to isolate variability in analysis practices, as reported in [1]. The manuscript specifies the additional Ni and Al components examined and notes their microstructural features. We selected these to include examples of broad grain-size distributions and anisotropic/non-convex grains. We acknowledge that the current set does not exhaustively cover every AM challenge (such as strong porosity effects or highly complex geometries) and that this limits claims of full generality. We will revise the text to explicitly state the number of components, describe their characteristics in more detail, and qualify the scope of the demonstration. revision: partial

Circularity Check

0 steps flagged

No significant circularity; proposal synthesized from external interlaboratory data

full rationale

The paper's central claim is an empirical proposal for a new EBSD grain-size standard, derived from results of a prior interlaboratory comparison study (Reference [1]) plus tests on Ni/Al AM components. No equations, fitted parameters, or mathematical derivations are present. The reference supplies input observations rather than a self-referential justification; the synthesis step does not reduce to a tautology or rename its own inputs. This is a standard empirical workflow with no load-bearing self-citation chain or self-definitional structure.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

Review performed on abstract only; no free parameters, invented entities, or non-standard axioms are described. The work rests on the domain assumption that EBSD grain size metrics can be standardized for heterogeneous AM microstructures via interlaboratory comparison.

axioms (2)
  • domain assumption There is currently no EBSD-based grain size measurement standard suitable for typical AM materials
    Explicitly stated in the abstract as the motivation for the study.
  • domain assumption Interlaboratory comparisons reliably identify appropriate metrics and summary statistics for grain size
    Implicit in the study design and the decision to base recommendations on participant reports.

pith-pipeline@v0.9.1-grok · 5685 in / 1362 out tokens · 57585 ms · 2026-06-30T19:21:56.400481+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

20 extracted references · 8 canonical work pages

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    AM components can have complex geometries and porosity which may affect the local microstructure

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    Other material-specific standards for grain size measurement also exist, such as ISO 4499 for WC grain size measurement in hardmetals

    both describe electron backscatter diffraction (EBSD)-based grain size measurements, but specify different requirements. Other material-specific standards for grain size measurement also exist, such as ISO 4499 for WC grain size measurement in hardmetals. ASTM E112 has been cited within the ‘Claims’ section of 242 patents between 1970 and 2024 [5], but ne...

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    The effective ‘change’ to the EBSD map is therefore equal to the fraction of unindexed points (6.69 % for this data)

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