Tensile Test Report — SLM Aluminium (AlSi10Mg)

Materials Test Report

Tensile Test of SLM
Aluminium Specimens

Mechanical characterisation of two reduced-section dog-bone specimens manufactured by Selective Laser Melting (SLM).

Project

SLM AlSi10Mg Material Qualification

Document No.

NES-TR-SLM-AL-001

Release

General release — material qualification record

Prepared by

Nour Engineering Solutions Pty Ltd

Issue Date

22 May 2026

Revision

Rev. 0 — Issued for Use

1.0 Executive Summary

This report presents the results of uniaxial tensile testing performed on two reduced rectangular section specimens manufactured by Nour Engineering Solutions (NES). The specimens were additively manufactured in aluminium alloy via Selective Laser Melting (SLM), printed directly to the dog-bone profile required for testing in accordance with AS 1391:2020 with no post-processing.

Testing was performed at SRG Global's NATA-accredited mechanical testing laboratory. The underlying NATA-endorsed test certificate is held on file by NES and is available on request (see Appendix A).

Summary of Results

UTS (avg)

286

MPa

0.2 % Proof (avg)

177

MPa

Elongation (avg)

Modulus (E)

GPa

Outcome: Both specimens cleared the published as-built SLM AlSi10Mg benchmarks (UTS ≥ 230 MPa, 0.2 % proof ≥ 150 MPa, A ≥ 3 %), with elongation at fracture of 10 % and 14 %. The two were built in orthogonal orientations — one in the X/Y plane, the other along Z — and the results sat within ~3 % on UTS and ~2 % on 0.2 % proof, so the build can be treated as isotropic in tension for design purposes. The material is suitable for the intended application.

2.0 Scope of Work

Monotonic tensile testing was performed on two as-supplied dog-bone specimens in order to establish the bulk mechanical properties of the SLM aluminium build. The objective was to:

Determine the Ultimate Tensile Strength (UTS), 0.2 % Proof Stress, Elongation at fracture and indicative Modulus of Elasticity.
Confirm batch consistency by testing two replicates from the same build.
Provide a customer-facing engineering record traceable to a NATA-accredited test certificate.

3.0 Specimens

Material

AlSi10Mg aluminium alloy — SLM (Selective Laser Melting)

Manufacturing process

Powder-bed laser fusion, NES additive manufacturing facility

Specimen geometry

Reduced rectangular section ("dog-bone") — see Figure 1

Nominal envelope

239 mm length × 32 mm grip × 10 mm thickness

Quantity tested

2 replicates (WS243658-1, WS243658-2)

WS243658-1 — build orientation

X/Y plane (long axis flat on build plate)

WS243658-2 — build orientation

Z direction (long axis vertical, normal to build plate)

Pairing the two orientations enables a direct check of build-direction anisotropy. The dog-bone geometry tested in accordance with AS 1391:2020 is shown in Figure 1 below; full dimensions, tolerances and surface finish are defined on drawing Dogbone AlSi10Mg (Rev. A), reproduced for reference.

Dogbone AlSi10Mg specimen drawing, Rev. A

Figure 1. Reduced rectangular section (dog-bone) specimen — drawing Dogbone AlSi10Mg, Rev. A. Overall length 239 mm, gauge section 60 mm × 20 mm × 10 mm, R20 transition radius.

4.0 Test Method

Test standard

AS 1391:2020 — Metallic materials, tensile testing at ambient temperature

Test laboratory

SRG Global — Mechanical Testing

Accreditation

NATA-accredited — ISO/IEC 17025 (Testing)

Date of test

12 May 2026

Ambient temperature

21 °C

Acceptance basis

Report findings (no pass/fail criterion imposed)

Each specimen was instrumented with an extensometer over an 80 mm gauge length and loaded monotonically to fracture. Force, stroke and extensometer signals were logged at 10 ms intervals and converted to engineering stress and engineering strain using the as-measured cross-section.

5.0 Results

5.1 Tabulated Results

Specimen ID	Build Orientation	Width × Thickness (mm × mm)	Area (mm²)	Gauge Length (mm)	0.2 % Proof Stress (MPa)	Tensile Strength (MPa)	Elongation (%)
WS243658-1	X / Y	20.15 × 10.17	204.93	80	175	290	10
WS243658-2	Z	20.16 × 10.18	205.23	80	178	281	14
Mean	—	—	205.08	80	177	286	12
Δ (X/Y vs Z)	—	—	—	—	1.7 %	3.1 %	4 pp
Strength differential between X/Y and Z builds is < 4 % for both UTS and 0.2 % proof, indicating an effectively isotropic tensile response. Modulus of Elasticity for both specimens was measured as 59 GPa (not covered under the SRG NATA scope of accreditation, reported for reference only).

5.2 Build-Orientation (Isotropy) Check

The two specimens were built in orthogonal orientations: WS243658-1 with its long axis in the X/Y plane of the build platform, and WS243658-2 with its long axis along the Z (build) direction. As-built SLM AlSi10Mg is widely reported to exhibit measurable anisotropy — typically with lower UTS and ductility in the Z direction due to weaker inter-layer bonding. The values measured here show only a 3.1 % difference in UTS and 1.7 % difference in 0.2 % proof stress between the two orientations, which is within normal test scatter. The build is therefore considered to behave isotropically under quasi-static tensile load, simplifying design treatment of the parts produced.

5.3 Indicative Comparison — Typical SLM AlSi10Mg

Property	This Test (mean)	Typical SLM AlSi10Mg (as-built)	Result
Ultimate Tensile Strength	286 MPa	230 – 460 MPa	Within range
0.2 % Proof Stress	177 MPa	150 – 270 MPa	Within range
Elongation at fracture	12 %	3 – 10 %	Exceeds typical
Modulus of Elasticity	59 GPa	65 – 75 GPa	Slightly below — see Chapter 6.0
Indicative ranges only; published values vary with powder lot, build orientation, layer thickness, heat treatment and machine vendor. Comparison provided for context, not as an acceptance criterion.

5.4 Strength Comparison — SLM AlSi10Mg vs Cast A380 Aluminium

The SLM AlSi10Mg build is benchmarked against A380 aluminium (AA A380.0-F, as-cast), a common incumbent material for die-cast structural aluminium components. The comparison below establishes whether the SLM build delivers equivalent or superior mechanical performance to the incumbent A380 die-casting. Typical mechanical properties for A380-F are drawn from ASM Aluminum & Aluminum Alloys (ASM Handbook Vol. 2) and the Aluminum Association's Standards for Aluminum Sand and Permanent Mold Castings.

Property	SLM AlSi10Mg (this test, mean)	A380 Aluminium (as-cast, typical)	Δ vs A380
Ultimate Tensile Strength	286 MPa	324 MPa	−12 %
0.2 % Proof / Yield Stress	177 MPa	159 MPa	+11 %
Elongation at fracture	12 %	3.5 %	+3.4 × (much more ductile)
Modulus of Elasticity	59 GPa	71 GPa	−17 %
Density	2.67 g/cm³	2.74 g/cm³	−2.5 % (lighter)
A380 reference values: UTS 324 MPa, Yield 159 MPa, Elongation 3.5 %, E ≈ 71 GPa, ρ 2.74 g/cm³ (ASM Handbook Vol. 2; The Aluminum Association). Comparison is illustrative — SLM AlSi10Mg and die-cast A380 differ in alloy chemistry, processing route and porosity character.

Take-away vs A380. The SLM AlSi10Mg build is within ~12 % of A380's ultimate tensile strength but delivers an ~11 % higher yield stress and over 3 × the elongation, meaning the design useful working stress (governed by yield, not UTS) is in fact higher than A380, and the material is markedly more damage-tolerant. The lower modulus and density are characteristic of the Al-Si-Mg system and consistent with a weight-sensitive, additively manufactured replacement for cast A380 brackets.

5.5 Stress–Strain Response

The engineering stress–strain curves for each specimen are shown below. Both responses exhibit the classical elastic–plastic profile of a ductile aluminium alloy, with a well-defined linear elastic region, smooth transition through yield, gradual strain hardening to peak load, and ductile rupture without abrupt brittle failure. The near overlap of the X/Y and Z curves through the elastic and early plastic regions visually reinforces the isotropy conclusion of Chapter 5.2.

Stress vs strain curve, specimen 1 (X/Y build)

Figure 2. Engineering stress vs strain — Specimen WS243658-1 (X/Y build). Peak stress 290 MPa at ≈ 9 % strain; fracture at ≈ 12 % strain.

Stress vs strain curve, specimen 2 (Z build)

Figure 3. Engineering stress vs strain — Specimen WS243658-2 (Z build). Peak stress 281 MPa at ≈ 9.5 % strain; fracture at ≈ 16 % strain.

5.6 Specimen Condition — Before and After Testing

Figures 4 and 5 below document the physical condition of the two dog-bone specimens immediately before mounting in the test machine and after tensile loading to fracture. The post-test image (Figure 5) shows red marker applied to the gauge section to highlight the fracture plane and any secondary cracking; the rule provides a scale reference.

As-supplied dog-bone tensile specimens prior to testing

Figure 4. As-supplied SLM AlSi10Mg dog-bone specimens prior to testing — WS243658-1 (X/Y build, top) and WS243658-2 (Z build, bottom). Both specimens were inspected for surface defects and confirmed dimensionally compliant with drawing Dogbone AlSi10Mg, Rev. A, before despatch to SRG Global.

Fractured tensile specimens after testing to UTS, with red marker applied

Figure 5. Specimens after tensile testing to fracture (labelled 1 = WS243658-1, 2 = WS243658-2), with red marker applied across the gauge section to expose the fracture plane. Both specimens fractured cleanly within the reduced gauge length — the failure location required by AS 1391:2020 — with localised necking and no evidence of fracture initiation at the grip transitions, voids or sub-surface defects. Failure morphology is consistent with ductile cup-and-cone rupture (refer Chapter 6.0).

6.0 Discussion

Strength. The mean ultimate tensile strength (286 MPa) and mean 0.2 % proof stress (177 MPa) both sit within the published as-built window for SLM AlSi10Mg. Inter-specimen variation in UTS was < 4 %, indicating good build-to-build repeatability across the two replicates.

Isotropy. With WS243658-1 built in the X/Y plane and WS243658-2 built along Z, the two specimens deliberately interrogate the dominant axis of anisotropy in SLM. The measured strength differential of 3.1 % on UTS and 1.7 % on 0.2 % proof falls well within the inherent test scatter for as-built AlSi10Mg, supporting the conclusion that the build is mechanically isotropic in tensile response. From a design standpoint this allows a single material allowable to be applied independent of part orientation on the build plate.

Comparison to A380. Benchmarked against typical cast A380 aluminium, the SLM AlSi10Mg build is ~12 % lower on UTS but ~11 % higher on yield (0.2 % proof) and more than three times more ductile. Because allowable design stress is yield-limited rather than UTS-limited for most ductile-aluminium structural components, the SLM build offers equivalent or greater usable strength than A380, at lower density and with substantially more reserve ductility before fracture. The trade is a ~17 % lower elastic modulus, which is geometry-correctable for stiffness-critical features.

Ductility. Elongation at fracture of 10 % and 14 % is notable — as-built SLM aluminium is typically quoted at 3 % to 10 %. The higher ductility observed here suggests favourable build parameters and a sound powder consolidation with low porosity. The ~4 % spread in elongation between the two specimens is consistent with the inherent variability of additively manufactured ductility metrics and does not indicate a process anomaly.

Modulus. The reported modulus of 59 GPa falls slightly below the typical 65 – 75 GPa range. This is most likely attributable to (a) extensometer-stroke compliance over the relatively short elastic region typical of cast/SLM Al-Si alloys, and (b) the fact that modulus determination is outside SRG's NATA scope and therefore reported as indicative only. The value is not considered a quality concern; if a certified modulus is required for design, a dedicated test with strain-gauge instrumentation is recommended.

Failure mode. Both curves show extended strain-hardening plateaus and a sharp drop at fracture, consistent with cup-and-cone ductile failure — i.e. no signs of premature brittle rupture or large internal defects.

7.0 Conclusion

The two SLM aluminium dog-bone specimens tested by SRG Global meet or exceed the typical mechanical performance benchmarks for as-built SLM AlSi10Mg, deliver an isotropic tensile response between X/Y and Z build orientations (< 4 % differential on UTS and yield), and outperform cast A380 aluminium on yield strength and ductility at lower density. On the basis of these results, the SLM AlSi10Mg build is considered mechanically suitable for its intended application, including as a substitute for A380 die-cast brackets. NES recommends retaining this report as the material qualification record for the current build campaign.

Recommendations

Retain witness coupons from each future production build for periodic tensile re-verification.
If the design case is fatigue- or stiffness-driven, perform supplementary fatigue testing and a strain-gauge modulus measurement.
Consider a T6 heat-treatment trial if higher proof stress is required for downstream load cases.

Joshua Nour

Director / Mechanical Engineer

Nour Engineering Solutions Pty Ltd
Josh.Nour@nesolution.com.au

Document

NES-TR-SLM-AL-001 — General release

SLM AlSi10Mg material qualification
Rev. 0 — 22 May 2026

Appendix A — SRG Global Test Certificate

The NATA-endorsed test certificate issued by SRG Global underpins all numerical results presented in this report. The certificate is held on file by Nour Engineering Solutions and can be made available to customers on request.

SRG Global — NATA-Endorsed Mechanical Test Certificate

NATA Accredited to ISO/IEC 17025 — Testing · Tensile testing to AS 1391:2020

Date of test: 12 May 2026
Certificate: Held on file by NES — available on request

Document Control

Rev.	Date	Description	Prepared	Approved
0	22 May 2026	Issued for use	J. Nour	J. Nour

Note. This report is published by Nour Engineering Solutions Pty Ltd as a representative material qualification record for its SLM aluminium (AlSi10Mg) build process. Client- and project-specific details have been omitted from this general-release edition; all numerical results remain traceable to the NATA-endorsed SRG Global certificate referenced above.