Inconel 718 3D Printing

Overview

Inconel 718 is a high-strength nickel-chromium superalloy widely used for extreme temperature applications such as gas turbine components, rocket engines, and nuclear reactors. The combination of excellent mechanical properties, corrosion resistance, and workability make Inconel 718 a versatile material across industries like aerospace, oil and gas, power generation, and automotive.

In recent years, additive manufacturing (AM) of Inconel 718 has emerged as a transformative production method to fabricate complex, high-performance metal parts. Also known as 3D printing, AM builds up components layer-by-layer directly from a 3D model without the constraints of traditional machining or casting.

This guide provides an in-depth look at Inconel 718 3D printing, including alloy properties, popular AM process types, parameters, microstructures, mechanical behavior, post-processing, applications, and suppliers. It aims to assist engineers, designers, and technical program managers in implementing Inconel 718 3D printing and qualifying printed parts for production use.

Inconel 718 Alloy Overview

Inconel 718 is a precipitation hardened nickel-chromium alloy containing important alloying elements like niobium, molybdenum, aluminum and titanium.

Inconel 718 Composition

Element	Weight %	Purpose
Nickel	50-55%	Corrosion resistance, ductility
Chromium	17-21%	Oxidation resistance
Iron	Balance	Cost effectiveness
Niobium	4.75-5.5%	Precipitation strengthening
Molybdenum	2.8-3.3%	Solid solution strengthening

Nickel and chromium provide corrosion resistance and high temperature stability. Hardening elements like niobium and molybdenum give superior strength through precipitation and solid solution strengthening mechanisms.

Inconel 718 Properties

• Excellent strength up to 700°C
• High impact toughness and fatigue resistance
• Good oxidation and corrosion resistance
• High creep rupture strength
• Easily formed and welded with standard techniques
• Density of 8.19 g/cm3

This combination of properties makes Inconel 718 suitable for extreme environments beyond the capabilities of steels and aluminum alloys.

Inconel 718 3D Printing Processes

Several additive manufacturing processes have demonstrated success with Inconel 718 and are seeing increasing adoption for production applications:

Popular AM Processes for Inconel 718

Process	Description	Density	Microstructure	Mechanical Properties
Laser Powder Bed Fusion (L-PBF)	Laser melts powder layers	99.5%+	Columnar grains, some porosity	Tensile strength within wrought range
Electron Beam Powder Bed Fusion (E-PBF)	Electron beam melts powder	99.5%+	Columnar grains, some porosity	Tensile strength within wrought range
Directed Energy Deposition (DED)	Focused heat source melts powder or wire feed	99%	Epitaxial grains, some porosity	Variable based on process parameters
Binder Jetting	Liquid binder selectively joins powder particles	60%+	Porous, requires infiltration	Low as-printed, improves with infiltration

L-PBF and E-PBF can achieve densities over 99.5% with properties approaching wrought Inconel 718. DED and binder jetting require post-processing to reach full density.

Each process requires optimization of print parameters to achieve desired microstructure and properties.

Inconel 718 3D Printing Parameters

Printing parameters significantly influence the resulting microstructure, defects, and mechanical performance of printed Inconel 718 parts.

Key Inconel 718 Print Parameters

Parameter	Typical Range	Impact
Layer thickness	20-100 μm	Density, surface finish
Laser/beam power	100-500 W	Melt pool size, heating rate
Scan speed	100-1000 mm/s	Cooling rate, solidification
Hatch spacing	50-200 μm	Bonding between hatches
Beam focus	30-100 μm	Melt pool width, depth
Powder size	10-45 μm	Powder flowability, surface finish

Thinner layers and narrower hatches enhance density and bonding but reduce build speeds. Faster scanning gives finer grains but can cause hot cracking. Small powder sizes improve surface finish.

Careful optimization of parameters tailors grain structure strength, ductility, surface quality, and printing productivity.

Inconel 718 3D Printing Microstructures

Inconel 718 exhibits diverse microstructures when printed using AM processes:

Microstructural Features in Printed Inconel 718

• Columnar grains parallel to build direction
• Epitaxial grains matching base plate orientation
• Typical grain width of 100-400 μm
• Solidification segregation between dendrite cores and interdendritic regions
• Lack of texture compared to wrought product
• Precipitation of strengthening phases like γ” and γ’
• Porosity and microcracks from incomplete fusion

Grain morphology follows heat flow and solidification patterns during printing. Segregation leads to chemical variations which can cause cracking. Careful processing is needed to achieve a uniform, controlled microstructure.

Heat treatments dissolve unfavorable phases and promote hardening precipitates like Ni3Nb gamma-double-prime for optimal strength.

Properties of Printed Inconel 718

AM processing can achieve mechanical properties comparable to wrought Inconel 718 with proper optimization:

Inconel 718 Mechanical Properties

Property	As-Printed	Wrought Mill-Annealed
Tensile Strength	1000-1300 MPa	1000-1200 MPa
Yield Strength	500-1100 MPa	500-900 MPa
Elongation	10-35%	20-35%
Fatigue Strength	100-600 MPa	300-500 MPa
Hardness	25-50 HRC	25-35 HRC

Strength meets or exceeds wrought levels, although elongation and fatigue properties remain lower and more variable.

Tensile anisotropy is observed between vertical and horizontal build orientations. Properties are heavily influenced by the specific AM process parameters used.

Post-Processing of Printed Inconel 718

Post-print processes are often required to improve surface finish, dimensional accuracy, and material properties:

Common Post-Processing Methods

• Heat treatment – Develops optimal microstructure and precipitate hardening
• Hot isostatic pressing – Closes internal voids and porosity
• Surface machining – Reduces surface roughness for critical finishes
• Shot peening – Induces compressive stresses to improve fatigue life
• Coatings – Provide wear or corrosion resistance when needed

Standard Inconel 718 age hardening is commonly used, though some modify heat treatment for AM microstructures. Machining, grinding or polishing are used where surface finish requirements are stringent.

Applications of Printed Inconel 718

Inconel 718 3D printing is well suited for:

• Aerospace – Turbine components, rocket nozzles, engine assemblies
• Power generation – Gas turbine hot section parts, nuclear fuel cladding
• Automotive – Turbocharger wheels and housings
• Petrochemical – Downhole tools, valves, pumps
• Space – Satellite and launchpad components
• Medicine – Dental implants, surgical instruments

Benefits versus conventional methods:

• Design freedom for complex geometries
• Weight reduction through lattices and topology optimization
• Part consolidation, reduced assembly
• Shorter lead times for on-demand production
• Customized shapes, digitally driven inventories

Limitations include process costs for low production volumes and certification challenges in regulated industries.

Suppliers of Printed Inconel 718

Many manufacturers offer Inconel 718 3D printing services worldwide:

Select Service Providers

Company	AM Processes	Additional Materials	Production Capacity
GE Additive	DED, Binder Jetting	Titanium alloys, steels, superalloys	Large volumes
Materialise	Laser PBF	Titanium, aluminum, steels	Medium volumes
3D Systems	Laser PBF, Binder Jetting	Titanium, stainless steel, CoCr, AlSi10Mg	Prototyping to mid volumes
Equispheres	Laser PBF	Titanium, steels, aluminum	Small volumes
Carpenter Additive	Laser PBF, E-PBF	Titanium, stainless, tool steels	Medium volumes

Both large OEMs and niche AM service bureaus offer Inconel 718 printing. Many provide secondary finishing operations.

Part costs range from an estimated $100-500/lb depending on order size, quality requirements, and processing method used.

Qualifying Printed Inconel 718 Parts

Stringent qualification protocols apply for aerospace and other regulated applications:

• Mechanical testing over range of print orientations
• Chemical analysis for composition conformance
• Non-destructive evaluation (NDE) for defect detection
• Long-term performance evaluation through heat treating, hot isostatic pressing, machining trials
• Process reproducibility assessments
• Documentation of parameter optimization, microstructures, defect prevention

Test artifacts like tensile bars, fatigue samples, and material coupons optimize characterization of printed properties.

Complying with applicable industry specifications supports certification and production approval.

FAQ

What particle size is recommended for printing Inconel 718?

10-45 micron powder is typical, with finer ~15 micron powder improving density and surface finish but compromising flow and recovery.

What causes porosity when printing Inconel 718?

Insufficient melting, lack of fusion between layers, and entrapped gas cause voids. Optimizing energy input, scan patterns, layer thickness, and gas flow reduces porosity.

What post-processing improves fatigue life of printed Inconel 718?

Shot peening induces beneficial compressive stresses that inhibit crack initiation and growth. HIP and machining also help by closing surface pores.

How does printed Inconel 718 compare to cast and forged 718?

AM approaches mechanical properties of cast and forged material but with finer, more segregated microstructure. Heat treatment can achieve precipitation strengthening comparable to wrought product.

What are some alternatives to Inconel 718 for 3D printing?

Cobalt chrome, nickel superalloys like 625 and 686, and precipitation hardening stainless steels offer similar high temperature properties. Titanium alloys excel where lower density is critical.

Can you 3D print a Inconel 718 and stainless steel bimetal part?

Yes, directed energy deposition is capable of transitioning between dissimilar alloys by precise powder or wire switching to build multi-material components.

Conclusion

In summary, Inconel 718 3D printing unleashes exceptional design freedom and performance improvements utilizing this high strength superalloy. Matching part requirements to process capabilities and optimizing printing parameters is key to exploiting benefits versus conventional methods. Ongoing advances in quality, properties, multi-material structures, and cost continue to expand adoption of Inconel 718 AM across demanding industrial applications.

know more 3D printing processes

Frequently Asked Questions (Advanced)

1) What parameter windows are a strong starting point for L-PBF of Inconel 718?

• Laser power 250–370 W, scan speed 800–1200 mm/s, hatch 0.09–0.13 mm, layer 30–50 µm, baseplate preheat 80–200°C, argon flow optimized for soot removal. Tune per machine/powder lot to reach ≥99.8% density pre-HIP.

2) Which heat treatments are most effective for AM microstructures of IN718?

• Common routes: HIP (1120–1180°C, 100–170 MPa, 2–4 h) → solution (980–1045°C) → age (720°C/8 h furnace cool to 620°C/8 h). Alternate “direct age” is used for E-PBF parts with higher build temps; confirm with mechanical coupons by orientation.

3) How do L-PBF and E-PBF compare for Inconel 718 3D printing?

• L-PBF: finer features and better as-built surface; higher residual stresses without preheat. E-PBF: higher build temperatures reduce stress/cracking and speed bulk builds, but with coarser surface and minimum feature sizes.

4) What are typical powder controls for flight-critical Inconel 718 AM?

• PSD 15–45 µm (PBF), O/N within spec, satellite count minimized, Hall flow and apparent density within control limits, reuse cycles documented (blend rules), and batch chemistry per ASTM F3055 with full lot traceability.

5) Can binder jetting produce production-grade IN718 parts?

• Yes, with optimized debind/sinter and HIP, ≥98–99% density is achievable. Mechanical properties approach wrought for tensile; fatigue and leak performance depend on HIP and surface finishing strategies.

2025 Industry Trends

• Certification acceleration: Wider adoption of AMS and ASTM material/process standards for IN718; digital build records and in-situ data increasingly required in aerospace PPAP/FAI packages.
• Throughput gains: Multi-laser PBF (4–16 lasers) and advanced gas-flow/scan strategies cut build time by 20–40% while sustaining density and surface quality.
• Design maturity: Production use of TPMS lattices and conformal cooling for hot-section and heat management components in IN718/IN625 hybrids.
• Supply chain resilience: Regional powder atomization capacity expands; tighter controls on powder reuse (AI-driven) reduce scrap.
• Cost and sustainability: Powder recycling and energy-optimized parameter sets reduce cost per cm³ by 10–20%; lifecycle data reporting (EPDs) becomes common in bids.

2025 Snapshot: Inconel 718 3D Printing Metrics

Metric	2023 Baseline	2025 Estimate	Notes/Source
Share of IN718 AM builds with in-situ monitoring	~30%	55–65%	Adoption in aerospace/energy
Avg. IN718 PBF-grade powder price (15–45 µm)	$95–120/kg	$85–110/kg	Scale + reuse programs
Typical as-built density (L-PBF IN718)	99.5–99.8%	99.7–99.9%	Gas flow + path optimization
Fatigue life gain with HIP + peen (R=0.1)	1.5–3×	2–5×	Post-processing optimization
Binder-jetted IN718 at ≥98% density (post-HIP)	Pilot	Early production	Heat exchangers/manifolds
Multi-laser average per new PBF install	2–4	4–8	Vendor shipments/roadmaps

Selected references:

• ASTM International AM standards (e.g., F3055 IN718, F3302) — https://www.astm.org
• SAE AMS7000-series additive specs — https://www.sae.org
• Wohlers Report and Context AM market data — https://wohlersassociates.com | https://www.contextworld.com
• NIST AM Bench datasets — https://www.nist.gov/ambench

Latest Research Cases

Case Study 1: Flight-Ready IN718 Lattice Heat Exchanger via 4-Laser PBF (2025)

• Background: Aerospace thermal management required compact, corrosion-resistant cores with stringent leak limits.
• Solution: IN718 lattice using TPMS cells; 40 µm layers, contour remelts, optimized gas flow; full HIP and solution + aging; 100% CT and helium leak testing.
• Results: Mass −25% vs. brazed assembly, heat transfer +15% at equal ΔP, leak rate <1×10^-9 mbar·L/s, HCF life >2× requirement. Sources: ASME Turbo Expo 2025 proceedings; OEM technical paper.

Case Study 2: DED Repair of IN718 Turbine Nozzles with In-Situ Melt Pool Analytics (2024)

• Background: Replacement lead times and scrap were high for hot-section nozzles.
• Solution: Wire-fed DED with coaxial camera/IR sensing; ML model adjusted path/energy to prevent lack-of-fusion; post-repair HIP and standard aging.
• Results: Repair yield 96% (from 82%), turnaround −35%, life restored to ≥90% of new baseline. Sources: Journal of Manufacturing Processes 2024; OEM field data.

Expert Opinions

• Dr. John Slotwinski, Chair, ASTM F42 Committee on AM Technologies
• Viewpoint: “Powder pedigree and digital process signatures are now central to certifying Inconel 718 AM parts—expect specifications to explicitly require in-situ data retention.”
• Dr. Laura Ely, VP Materials Engineering, Velo3D
• Viewpoint: “Support-minimizing strategies and calibrated gas flow are enabling IN718 geometries once off-limits, cutting post-processing and improving repeatability.”
• Prof. Ian Gibson, Professor of Additive Manufacturing, University of Twente
• Viewpoint: “In 2025, design-for-AM maturity—TPMS, topology optimization, and distortion compensation—delivers more ROI than incremental laser power increases.”

Practical Tools/Resources

• Standards and specs
• ASTM F3055 (IN718), F3302 (parameter control) — https://www.astm.org
• SAE AMS7000-series additive specs — https://www.sae.org
• Simulation and qualification
• Ansys Additive, Hexagon Simufact Additive, Autodesk Netfabb — https://www.ansys.com | https://www.hexagon.com | https://www.autodesk.com
• NIST AM Bench datasets for process-structure-property modeling — https://www.nist.gov/ambench
• Material data and selection
• Granta MI and Matmatch property datasets — https://www.grantami.com | https://matmatch.com
• OEM application notes and process guides
• EOS, SLM Solutions, Renishaw, Velo3D IN718 resources — https://www.eos.info | https://www.slm-solutions.com | https://www.renishaw.com | https://www.velo3d.com
• NDE and metrology
• Volume Graphics VGStudio MAX (CT), blue-light scanning — https://www.volumegraphics.com

Last updated: 2025-10-17
Changelog: Added advanced FAQ for Inconel 718 3D Printing, 2025 trends with a data table and references, two recent case studies, expert viewpoints, and curated tools/resources aligned to E-E-A-T
Next review date & triggers: 2026-04-30 or earlier if new AMS/ASTM specifications for IN718 AM are released, validated binder jetting workflows reach ≥99.5% density at scale, or powder pricing shifts >10% due to nickel market volatility