Macrotching Metallography Testing Services for Aerospace & Oil & Gas 

Reveal Flow Lines, Fusion, and Forging Integrity Accredited Results at Production Speed 

Why Macroetching Testing Matters 

For forgings, bar/plate, castings, and weldments in flight-critical and high-pressure systems, hidden discontinuities and poor flow can drive fatigue initiation, leak paths, and premature failure. Macroetching quickly confirms forging grain flow orientation, detects laps, seams, and bursts, verifies weld fusion and penetration, and screens for segregation/centerline shrink, supporting MRB decisions, supplier approvals, and compliance to drawings and program specs. 

AADFW’s Approach: Precision, Speed, and Proof 

• Accredited & precise: Work executed under ISO/IEC 17025 with controlled surface prep, reagent concentration, etch time/temperature, and calibrated imaging—producing clear, repeatable macrostructures. 

• Faster results: Alloy-specific procedures, standardized photo-plate templates, and proactive communication deliver decision-ready reports without rework delays. 

• Trusted by engineers: Audit-ready documentation with location maps, acceptance callouts, and practical recommendations that stand up to OEM and regulatory reviews. 

Macroetching Testing Capabilities 

• Specimen Selection & Sectioning 
  Representative cross-sections at highest-risk locations (flash lines, fillets, first engaged thread for fasteners, weld crown/root, mid-thickness/centerline for bar/plate). Non-thermal sectioning preserves structure. 

• Surface Preparation for Etch 
  Progressive grinding to a uniform finish; edge preservation for near-surface defects; solvent degrease to ensure even etch. 

Alloy-Appropriate Etchants & Techniques 

• Steels/Low-Alloy: Nital, Picral, Vilella for flow lines, bursts, laps/seams, decarb boundaries. 

• Stainless & Ni-Base: 50/50 HCI/Vilella variants to show fusion, delta/sigma indications in weld macro. 

• Aluminum: Keller’s/NaOH to reveal flow/segregation and weld penetration. 

• Titanium: Kroll for macro features and weld fusion limits. 
  Etch strength/time tailored to geometry and objective; rinse/neutralize/passivate steps documented. 

What We Document & Measure 

• Forgings & Bar/Plate: Grain-flow direction/continuity, laps/seams, bursts, centerline soundness, banding and segregation patterns. 

• Fasteners: Head/shank flow orientation, head-to-shank transition, upset defects, fold-over, laps. 

• Welds: Fusion/penetration, toe blending, lack of fusion, undercut/undercrown indicators; macro-scale porosity/slag lines. 

• Heat-Treat/Process Effects: Quench cracks, overheating/grind burn screen (per nital-etch practices), surface carbon condition corroboration (with micro follow-up when specified). 

• Optional Corroboration 
  Micro-exams of suspect regions; microhardness traverses for decarb/case confirmation; OES/C/S/O/N/H chemistry for grade/cleanliness checks. 

• Reporting & Traceability (Audit-Ready) 
  Photo plates with scale bars, etchant type/strength/time, etch lot and temperature; annotated defects/flow; acceptance table (go/no-go) tied to drawing/spec; instrument/calibration references and full chain of custody. 

Industries We Support

• Aerospace: Forged lugs, pins, gear/strut components, structural fasteners, and weldments, macro evidence aligned to OEM/FAA expectations. 

• Oil & Gas: Pressure-boundary forgings, valve bodies, bar/plate for subsea and sour-service; weld procedure/production verification. 

• Defense & Advanced Manufacturing: Mission-critical forgings and welded assemblies requiring documented flow and fusion quality. 
  Trusted by engineers and QC managers across mission-critical industries. 

Accreditations & Standards Compliance 

AADFW operates to ISO/IEC 17025 and supports Nadcap-driven program requirements. Macroetching is performed to applicable standards and customer/OEM specs, including: 

• ASTM E340 (macroetching metals and alloys) — widely used for general macroetch practice 

• ASTM E381 (flow lines and internal discontinuities in steel bars, billets, blooms, and forgings) 

• ASTM E3 (specimen preparation) • ASTM E407 (etchants for metallography) 

• OEM/prime procedures matched exactly when cited in purchase documents 

When your print calls out a specific method (field sizes, severity ratings, acceptance classes), we align our fixtures, etch parameters, and documentation accordingly. 

Why Engineers Choose AADFW

• Accredited & audit-ready macroetch with consistent, high-contrast photo plates. 

• Faster turnaround—alloy-specific routes and standard templates keep gates on schedule. 

• Trusted partner to aerospace and oil & gas QA teams. 

• Expert metallurgists who translate macro indications into clear go/no-go decisions and corrective actions (die, process, or weld adjustments). 

Request a Quote for Macroetching Testing 

Confirm flow, fusion, and soundness before parts hit the next gate. Request a Quote to schedule macroetching today.