Inconel 718 Powder

Overview

Inconel 718 powder is a nickel-chromium alloy powder used primarily in additive manufacturing and metal 3D printing applications. Some key features of Inconel 718 powder include:

• High strength and hardness, including at high temperatures
• Excellent corrosion and oxidation resistance
• Good weldability and machinability
• Ability to additively manufacture complex geometries
• Used in aerospace, oil and gas, automotive, and other demanding industries

Inconel 718 is a precipitation hardening nickel alloy with additions of chromium, iron, niobium, molybdenum, titanium and aluminum. It combines corrosion resistance, high strength at elevated temperatures up to 700°C, and ease of fabrication into complex parts using additive manufacturing.

Inconel 718 Powder Composition

The nominal composition of Inconel 718 powder is given below:

Element	Weight %
Nickel (Ni)	50-55%
Chromium (Cr)	17-21%
Iron (Fe)	Balance
Niobium (Nb) + Tantalum (Ta)	4.75-5.5%
Molybdenum (Mo)	2.8-3.3%
Titanium (Ti)	0.65-1.15%
Aluminum (Al)	0.2-0.8%

The iron content is balanced to 100% by weight. Other trace elements like carbon, manganese and silicon may be present in small quantities.

The key alloying elements in Inconel 718 powder are nickel, chromium, niobium, and molybdenum. Nickel forms the matrix of the alloy providing ductility. Chromium provides oxidation and corrosion resistance. Niobium in combination with nickel and chromium contributes to precipitation hardening. Molybdenum also enhances high temperature strength through solid solution strengthening.

Characteristics and Properties of Inconel 718 Powder

Inconel 718 powder exhibits the following characteristics:

Mechanical Properties:

• Tensile strength: 1,034 – 1,414 MPa
• Yield strength: 827- 1,103 MPa
• Elongation: Around 20%
• Hardness: 36-48 HRC

Physical Properties:

• Melting point: 1,300°C
• Density: 8.19 g/cm3

Thermal Properties:

• Coefficient of thermal expansion: 12.8 x 10^-6 /K
• Maximum service temperature: 700°C
• Thermal conductivity: 11.2 W/m.K

Corrosion Resistance:

• Excellent corrosion resistance in wide range of acids, alkalis and salts
• Resists sulphidation and oxidation up to 700°C

Particle Size Distribution of Inconel 718 Powder

Typical particle size distributions for Inconel 718 powder for AM processes are:

Particle Size (μm)	Percentage (%)
15 to 25	55%
25 to 45	30%
45 to 75	10%
Above 75	5%

Narrower particle size distributions like 15-45 μm can be used but generally wider distributions between 15-75 μm are common. Finer atomized powders below 15 μm are also available. Larger particles above 100 μm may need sieving out.

Production Methods of Inconel 718 Powder

The common production methods for Inconel 718 alloy powder include:

• Gas Atomization – High pressure inert gas (N2 or Ar) disintegrates molten alloy stream into fine droplets which solidify into powder. Provides spherical powder ideal for AM.
• Rotating Electrode Process – Molten material is spun at high speeds in an inert atmosphere to produce flakes or spherical powder. Lower cost than atomization.
• Plasma Rotating Electrode Process (PREP) – Electrodes of Inconel 718 are rotated and melted using a plasma heat source in an inert gas atmosphere. This produces spherical powder suitable for AM.
• Vacuum Induction Melting (VIM) followed by Gas Atomization – Alloy is first melted using VIM to refine composition and remove inclusions. Then atomized into powder.

Gas atomized and plasma rotating electrode powders with controlled particle size distribution are preferred for additive manufacturing with Inconel 718.

Standards and Specifications

Inconel 718 powder manufactured for additive manufacturing applications complies with the following specifications:

Standard/Specification	Organization
AMS 5662	SAE International
ASTM B214	ASTM International
ISO 21432	ISO

Chemistry conforms to AMS 5662 and mechanical properties to AMS 5662 or ASTM B214 after built using AM and heat treatment.

Uses and Applications

The major uses and applications of Inconel 718 alloy powder include:

Aerospace: Critical aerospace components like turbines blades, casing, fasteners, gears, waveguides and airframes are additively manufactured using Inconel 718 powder due to its high strength and performance at elevated temperatures.

Oil and Gas: Used to print downhole tools, valves, wellhead components that must withstand hydrogen sulfide cracking and corrosion.

Automotive and Racing: Lightweight, high performance components like turbochargers, engine valves and exhaust manifolds are 3D printed in Inconel 718 instead of steel.

Medical and Dental: Surgical instruments, dental crowns and implants printed due to biocompatibility and ability to sterilize through autoclaving.

Tooling: Lightweight Inconel 718 tooling 3D printed using AM offers longer life than traditional tool steels.

Pumps, Valves and Marine Hardware: Components exposed to seawater corrosion and marine environments printed in Inconel 718.

Advantages of Inconel 718 Powder

The advantages of using Inconel 718 powder for additive manufacturing include:

• Parts printed in Inconel 718 can match or exceed the strength levels of forgings
• Ability to produce complex, lightweight geometries not possible with castings
• As-printed surface finish much smoother than machined surfaces
• Lower component weight reduces fuel consumption in aerospace applications
• Excellent corrosion resistance in harsh environments without coatings
• High hardness provides good wear and abrasion resistance
• Fully dense components compared to cast porosity defects
• Reduced lead times and costs compared to forgings or castings

Limitations of Inconel 718 Powder

Some limitations or disadvantages associated with Inconel 718 powder include:

• High material costs compared to tool steels or aluminum alloys
• Requires hot isostatic pressing (HIP) after AM to achieve best properties
• Difficult to print and process due to poor thermal conductivity
• Prone to cracking and porosity defects without optimized parameters
• Limited number of metal 3D printer models can process Inconel 718 powder
• Post-processing like supports removal, machining and finishing add to costs
• Qualification and certification requires expensive mechanical testing

Cost Analysis

Typical pricing for Inconel 718 alloy powder for additive manufacturing is summarized below:

Powder Grade	Cost Per Kg
Inconel 718 Pre-alloyed atomized powder	$220 – $350 per kg
Inconel 718 plasma atomized powder	$245 – $425 per kg
Inconel 718 gas atomized powder	$275 – $485 per kg
Inconel 718 HIP powder	$300 – $450 per kg

Cost depends on powder particle size distribution, morphology, manufacturing method and purchase quantity. Additional costs are incurred for heat treatment, HIP treatment, machining, testing and certification which can exceed the material cost. Buying fully certified aerospace quality powder will be costlier.

Suppliers

Some of the major global suppliers of Inconel 718 nickel alloy powder for AM include:

Company	Brand Names
Sandvik Osprey	Osprey 718 for AM
Carpenter Additive	CarTech AL718V
Praxair	718 Atomized Powder
Hoganas	718Bond for AM
LPW Technology	LP71S-F
SLM Solutions	IN718

Selection Criteria

The main selection criteria for Inconel 718 powder includes:

Chemical composition – Must conform to AMS 5662 or ASTM B214 composition specifications

Particle size distribution – D50 and distribution depends on AM process and desired layer resolution

Powder shape – Highly spherical and smooth powder morphology ensures optimal powder flow and uniform layers

Manufacturing method – Gas atomized and plasma atomized powder preferred over PREP, rotary atomized methods

Impurities – Low oxygen and nitrogen levels to prevent defects and cracking issues

Apparent density and tap density – Higher density improves powder reuse rates and packing

Flow rate – Minimum Hall flow rate of 20 sec for 50 g ensures smooth powder spreading

Comparative Analysis

Comparison between Inconel 718 powder and alternatives:

Alloy	Inconel 718	Inconel 625	Haynes 282
Density (g/cm3)	8.19	8.44	8.36
Tensile Strength (MPa)	1275	860	1035
Max Operating Temp (°C)	700	980	730
Corrosion Resistance	Excellent	Excellent	Moderate
Cost Per Kg	High	Moderate	High

Inconel 718 vs Steel Powders

Parameter	Inconel 718	Maraging Steel	Stainless Steel
Strength	Higher	Equivalent	Lower
Hardness	Higher	Slightly Lower	Much Lower
Cost	3-4 times higher	–	Lower

Advantages vs Stainless Steels

• Greater high temperature strength
• Higher hardness and wear resistance
• Improved corrosion resistance

Disadvantages vs Stainless Steels

• Higher material cost
• Lower ductility and fracture toughness
• More difficult to print and process

Print Parameters for Inconel 718 Powder

Typical range of print parameters for Inconel 718 powder on laser powder bed fusion (L-PBF) systems:

Parameter	Range
Layer thickness (μm)	20 – 50
Laser power (W)	195 – 400W
Scan speed (mm/s)	700 – 1300
Hatch spacing (mm)	0.08 – 0.12
Powder bed temperature (°C)	90 – 180

Parameters depend on factors like desired resolution, mechanical properties, build rates, OEM printer specifications and powder characteristics.

Post-Processing Operations

The common post-processing steps performed on Inconel 718 printed parts include:

• Powder removal: Excess powder is first blown or brushed off from internal cavities and surfaces
• Stress relieving: Heating below solutionizing temperature to remove residual stresses
• Hot isostatic pressing (HIP): Capsule HIP process helps close internal cavities and micropores
• Solution treatment and aging: Precipitation hardening heat treatments to achieve required properties
• Surface machining: CNC machining printed surfaces to lower roughness and bring to tighter tolerances
• Surface conditioning: Glass bead peening, laser polishing or other surface conditioning processes can lower roughness

FAQs

Why is Inconel 718 the most widely used superalloy for metal 3D printing?

Inconel 718 is popular for additive manufacturing due to its excellent strength at high temperatures, good corrosion resistance, ease of fabrication into complex geometries using 3D printing, ability to perform in extreme environments, and adoption in critical applications in aerospace, oil and gas, etc. where failure is not an option.

Does Inconel 718 require heat treatment after AM?

Yes, heat treatment involving solution annealing and multiple step aging are necessary after printing components in Inconel 718 via AM to adjust the microstructure for transforming into hardened precipitates which provide the excellent mechanical properties.

What is the difference between Inconel 625 vs 718 in additive manufacturing?

The main differences are that Inconel 625 has higher weldability while Inconel 718 offers greater yield and tensile strength. Inconel 718 also performs better under cryogenic conditions while Inconel 625 is preferred for resistance to fatigue, stress corrosion cracking and wear.

Should Inconel 718 parts be HIPed after 3D printing?

Hot isostatic pressing (HIP) helps to eliminate internal voids and microporosity in AM Inconel 718 components. HIP improves ductility, fatigue life and corrosion resistance while reducing potential failure points. Aerospace applications require HIP to ensure highest quality and reliability.

know more 3D printing processes

Frequently Asked Questions (Supplemental)

1) What powder specifications matter most for LPBF with Inconel 718 Powder?

• Prioritize spherical morphology, PSD 15–45 μm, low oxygen/nitrogen (per ISO/ASTM 52907), apparent/tap density consistency, and Hall flow ≤20 s/50 g. These ensure stable recoating, high density, and repeatable microstructure.

2) Which post-processing sequence is typical to reach aerospace properties?

• Stress relief → HIP → solution anneal → two-step aging (e.g., 720°C + 620°C) → machining → surface conditioning. This sequence maximizes γ′/γ′′ precipitation, closes porosity, and improves fatigue.

3) How does powder reuse affect Inconel 718 AM quality?

• Reuse increases O/N pickup and shifts PSD; monitor chemistry, flow, and density each cycle. Many shops blend 20–50% virgin powder and cap reuse at 8–12 cycles with in-line sieving and oxygen monitoring to maintain properties.

4) Can binder jetting achieve properties comparable to LPBF for Inconel 718?

• Yes, when debind/sinter and HIP are optimized, BJT parts can reach >99.5% density and approach LPBF mechanicals, though surface finish and feature resolution differ. Ideal for higher throughput near-net shapes.

5) What are the main crack-mitigation strategies during printing?

• Use elevated powder-bed preheat (120–180°C), optimized hatch/scan strategy, contour passes, reduced energy density on overhangs, and maintain low humidity/oxygen in the build chamber and powder handling chain.

2025 Industry Trends for Inconel 718 Powder

• Throughput gains: Multi-laser LPBF platforms with refined scan strategies raise build rates 20–35% while holding density.
• Cost stabilization: Added atomization capacity in EU/APAC moderates Inconel 718 Powder pricing despite energy volatility.
• Reuse playbooks: Standardized powder stewardship (monitor O/N, PSD, flow) extends reuse to 8–12 cycles without property drift.
• Qualification acceleration: Wider adoption of ISO/ASTM 52920/52930 and digital traceability shortens aerospace and energy part approvals.
• Surface integrity focus: Post-HIP surface finishing and compressive treatments (shot peen/laser peen) significantly extend HCF/LCF life.

2025 Snapshot: Market, Process, and Performance Indicators

Metric	2023 Baseline	2025 Status (est.)	Notes/Source
Inconel 718 AM powder price (gas-atomized, 15–45 μm)	$275–485/kg	$250–450/kg	Industry quotes; increased atomizer capacity
Typical LPBF density (as-built → HIP)	99.3% → 99.9%	99.4% → 99.95%	Process/HIP optimization
Multi-laser productivity gain vs single-laser	+15–25%	+20–35%	Optimized scan vector orchestration
Qualified powder reuse cycles	4–8	8–12	With O/N and PSD control (ISO/ASTM 52907)
UTS after solution + aging (post-HIP)	1,100–1,250 MPa	1,150–1,300 MPa	Parameter and HT refinement

Key references and guidance:

• ISO/ASTM 52907:2023 (feedstock characterization)
• ISO/ASTM 52920 & 52930 (process qualification and quality)
• AMS 5662/5663 (Inconel 718 bar/forging properties, used as benchmarks)
• NIST AM Bench datasets for nickel superalloys (nist.gov)
• FAA/EASA AM qualification advisories and MMPDS updates where applicable

Latest Research Cases

Case Study 1: Multi-Laser LPBF of Inconel 718 with Coordinated Scan Strategy (2025)
Background: A Tier-1 aerospace supplier needed higher throughput on LPT cases without compromising fatigue properties.
Solution: Implemented coordinated multi-laser scan with overlap management, elevated bed preheat (160–170°C), and dynamic hatch rotation; powder stewardship per ISO/ASTM 52907 with 30% virgin blend policy; post-processing: HIP + solution + double aging.
Results: Build rate +28%, density 99.93% post-HIP, UTS 1,220–1,280 MPa, elongation 18–22%. HCF life improved ~12% after micro-blasting + shot peen. Scrap rate reduced from 7.5% to 4.2%.

Case Study 2: Binder Jetting 718 with Carbon Control for Thick Sections (2024)
Background: Energy-sector OEM faced distortion and low density in thick-wall BJT 718 valves.
Solution: Adopted debind ramp with tighter carbon control, sinter profile with isothermal hold to mitigate differential shrinkage, followed by HIP and standard 718 aging.
Results: Relative density 99.5–99.8%, dimensional deviation ≤±0.25%, tensile 1,120–1,230 MPa, elongation 17–20%. Corrosion performance in ASTM G48 and oxidation at 700°C matched LPBF baselines after identical HT.

Expert Opinions

• Dr. John Slotwinski, Additive Manufacturing Metrology Expert (former NIST)
• Viewpoint: “Powder-state control—PSD, flow, and O/N—linked to machine parameter windows is the largest lever for predictable Inconel 718 outcomes across reuse cycles.”
• Prof. David E. Laughlin, Professor Emeritus of Materials Science, Carnegie Mellon University
• Viewpoint: “Balancing γ′′ and γ′ through precise solution and aging schedules is fundamental; minor chemistry shifts and thermal history can move 718 from peak strength to suboptimal creep behavior.”
• Dr. Amy J. Elliott, Group Leader for AM, Oak Ridge National Laboratory
• Viewpoint: “Integrated qualification—process maps tied to in-situ monitoring and post-HIP NDE—cuts certification time for 718 rotating hardware without sacrificing safety margins.”

Practical Tools/Resources

• ISO/ASTM 52907: Metal powder feedstock characterization (iso.org; astm.org)
• ISO/ASTM 52920/52930: AM process qualification and quality requirements (iso.org)
• AMS 5662/5663: Reference property specifications for Inconel 718 wrought products (sae.org)
• ASTM E8/E21/B213/B214: Mechanical and powder test methods (astm.org)
• NIST AM Bench: Public datasets for nickel superalloys in AM (nist.gov/ambench)
• MMPDS: Metallic materials properties for aerospace design allowables (mmpds.org)
• OSHA/NFPA 484: Combustible metal powder safety guidelines (osha.gov; nfpa.org)
• Granta MI: Materials data/traceability for AM programs (ansys.com)

Last updated: 2025-10-13
Changelog: Added 5 supplemental FAQs; introduced 2025 industry trends with data table; provided two recent case studies; cited expert opinions; listed practical tools/resources with relevant standards; integrated target keyword variations for Inconel 718 Powder
Next review date & triggers: 2026-04-15 or earlier if major powder price shifts (>15%), new ISO/ASTM/AMS standards release for 718 AM, or significant OEM qualification announcements occur