GH3625 powder(Inconel 625 powder)

Overview

GH3625 powder is an alloy powder used for metal additive manufacturing processes like selective laser sintering (SLS) and direct metal laser sintering (DMLS). It is a nickel-based superalloy that offers high strength, corrosion resistance, and excellent high-temperature properties.

GH3625 is designed specifically for additive manufacturing to produce complex, dense parts with exceptional mechanical properties comparable to wrought materials. It enables the production of lightweight components with complex geometries for aerospace, automotive, medical, and industrial applications.

This guide provides a detailed overview of GH3625 powder covering its composition, properties, applications, specifications, pricing, advantages, and limitations. Comparisons are made to other common alloys like Inconel 718 and Stellite 21 to highlight the performance and suitability of GH3625 for different uses. An FAQ section addresses key questions about this material.

GH3625 Powder Composition

GH3625 has a complex chemical composition designed to provide a combination of high strength, resistance to thermal fatigue, oxidation, and corrosion resistance. Here is an overview of its composition:

Element	Weight %
Nickel	Balance
Chromium	15-17%
Cobalt	10%
Molybdenum	8-10%
Tantalum	5-6%
Aluminum	1.2-1.7%
Titanium	0.5-1.2%
Boron	0.01%

Nickel forms the base of this superalloy providing ductility and toughness. Elements like chromium, cobalt, and molybdenum contribute to high temperature strength through solid solution strengthening.

Tantalum provides solid solution strengthening and forms carbide particles for precipitation hardening. Aluminum and titanium form the gamma prime phase Ni3(Al,Ti) to give excellent high temperature mechanical properties. Boron enhances grain boundary strength.

The balanced composition gives GH3625 powder excellent weldability compared to precipitation hardening stainless steels. It can be easily post-processed through hot isostatic pressing (HIP), heat treatment, and machining.

GH3625 Powder Properties

GH3625 powder has the following physical and mechanical properties that make it suitable for demanding applications:

GH3625 Powder Properties

Property	Value
Density	8.1-8.5 g/cc
Melting Point	1260-1335°C
Thermal Conductivity	11-12.5 W/mK
Coefficient of Thermal Expansion	12.5-13.5 x 10<sup>-6</sup>/K
Modulus of Elasticity	156-186 GPa
Poission’s Ratio	0.29-0.33
Tensile Strength	1050-1280 MPa
Yield Strength (0.2% offset)	860-1050 MPa
Elongation	8-15%
Hardness	32-38 HRC

The high melting point, thermal conductivity, and low coefficient of thermal expansion enable good dimensional stability under high temperature service environments up to 1000°C for limited periods.

The alloy has excellent tensile and yield strength comparable to wrought materials along with good ductility and fracture toughness. It exhibits high hardness, resistance to wear, galling, and abrasion.

The properties allow GH3625 to outperform stainless steels, cobalt alloys, and even rival precipitation hardening nickel superalloys in high temperature strength. It also offers better weldability than Inconel 718.

GH3625 Powder Applications

The combination of high strength, hardness, toughness, and thermal stability makes GH3625 suitable for:

GH3625 Applications

Industry	Components
Aerospace	Turbine blades, combustor parts, nozzle guide vanes
Automotive	Turbocharger wheels, manifolds, valves
Oil and Gas	Wellhead parts, downhole tools, valves
Power Generation	Heat exchangers, burner components
Chemical Processing	Pump impellers, valves, reaction vessels
Medical	Dental implants, prosthetics, surgical instruments

The ability to 3D print complex geometries allows consolidating multiple parts into single components and lightweight lattice structures. This enables faster printing of single-piece components versus assembling multiple sections.

GH3625 is used to print blades, impellers, plates, discs, tubes with conformal cooling channels, and other mission-critical components working under high pressures and temperatures.

GH3625 Powder Specifications

GH3625 powder for AM processes is available in different size distributions, shapes, and formulations from various powder manufacturers.

GH3625 Powder Types

Specification	Details
Particle Size Distribution	15-45 μm, 15-53 μm, 53-150 μm
Particle Shape	Spherical, satellite, polyhedral
Alloy Modifications	With B, C, Zr, Nb, Ta
Manufacturing Method	Gas atomization, plasma atomization

Gas atomization and plasma atomization produce spherical powders optimal for SLS/DMLS processes. Satellite powders have higher tap density and improve powder flowability.

Smaller 15-45 μm powders provide high resolution and surface finish while larger 53-150 μm allow faster build speeds. Different alloying additions like boron, carbon, zirconium, niobium, and tantalum are used to tailor material properties.

GH3625 Powder Standards

Standard	Description
ASTM F3056	Standard specification for additive manufacturing nickel alloy
AMS7016	Nickel alloy powder for high temperature service
ASME B46.1	Surface texture requirements

GH3625 powder is qualified based on composition limits, particle size distribution, morphology, flowability, apparent density, and microstructure per ASTM F3056. Additional testing as per application standards is required.

GH3625 Powder Pricing

GH3625 powder is more expensive than stainless steel powders due to the complex composition and proprietary nature. Here are typical price ranges:

GH3625 Powder Cost

Powder Grade	Price Range
GH3625	$90-200 per kg
GH3625 + Boron	$110-250 per kg
GH3625 + Carbon	$100-220 per kg

Prices vary based on order quantity, particle size distribution, shape, manufacturing method, supplier, and additional powder characterization or qualification requirements.

GH3625 Powder Pros and Cons

GH3625 has the following advantages that make it a popular choice:

GH3625 Pros

• Excellent strength and hardness up to 1000°C
• Good corrosion and oxidation resistance
• Weldable for post-processing
• Higher ductility than Inconel 718
• Can be age hardened by heat treatment
• Complex geometries enabled by AM
• Faster and cheaper than castings
• Reduces part count through consolidation

GH3625 Cons

• More expensive than stainless steels
• Lower strength than Inconel 718 above 550°C
• Susceptible to strain-age cracking
• Requires hot isostatic pressing (HIP)
• Difficult to machine – requires specialist tools
• Limited supplier data on long term performance

Proper selection of AM process parameters and post-processing mitigates some of the limitations of GH3625 powder.

Comparison of GH3625 with Inconel 718 and Stellite 21

GH3625 occupies a niche between Inconel 718 and Stellite 21 in terms of properties and cost:

Alloy Comparison

Property	GH3625	Inconel 718	Stellite 21
Cost	Medium	High	Low
Density	High	Medium	High
Strength	Medium	Very High	Medium
Hardness	High	Medium	Very High
Wear Resistance	Medium	Low	Very High
Corrosion Resistance	Medium	High	Medium
Oxidation Resistance	Medium	High	Medium
Thermal Stability	Up to 1000°C	Up to 700°C	Up to 900°C
Weldability	Good	Poor	Medium
Manufacturability	Medium	Difficult	Easy

GH3625 matches or exceeds the performance of Stellite 21 cobalt alloys in wear and corrosion resistance but at lower cost. It approaches the strength of Inconel 718 up to 550°C and offers better weldability and manufacturability.

This makes it a cost-effective alternative for many applications requiring performance between these standard alloys. The ability to 3D print complex geometries also gives it an edge.

GH3625 Powder – FAQs

Q: What is GH3625 powder?

A: GH3625 is a nickel-based superalloy powder specifically designed for additive manufacturing processes like selective laser sintering (SLS) and direct metal laser sintering (DMLS). It provides an excellent combination of high temperature strength, hardness, wear and corrosion resistance.

Q: What is GH3625 powder used for?

A: GH3625 powder is used to 3D print critical components like turbine blades, manifolds, impellers, heat exchangers that require high mechanical properties, dimensional stability, and thermal resistance up to 1000°C. It finds applications across aerospace, automotive, energy, chemical processing, and medical industries.

Q: What metal 3D printing processes use GH3625 powder?

A: Selective laser sintering (SLS) and direct metal laser sintering (DMLS) are powder bed fusion 3D printing processes commonly used with GH3625 powder. Binder jetting is also suitable for GH3625.

Q: What are the material properties of GH3625?

A: GH3625 has excellent tensile strength 1050-1280 MPa, yield strength 860-1050 MPa, and hardness 32-38 HRC similar to wrought materials. It has good ductility of 8-15% elongation and high resistance to wear, galling, abrasion, and corrosion. Thermal properties allow use up to 1000°C.

Q: Does GH3625 powder require heat treatment?

A: Yes, GH3625 parts printed using SLS/DMLS require hot isostatic pressing (HIP) followed by heat treatment to achieve optimal mechanical properties, material consolidation, and microstructure. HIP helps close internal pores and voids.

Q: Is GH3625 weldable?

A: GH3625 is designed to have excellent weldability compared to precipitation hardening stainless steels and Inconel 718. This allows repairing and joining AM GH3625 parts through welding. Stress relieving may be required after welding to prevent cracking.

Q: Is GH3625 machinable?

A: GH3625 is difficult to machine compared to stainless steel and requires high-speed machining with specialist carbide tools. Tool wear is higher so optimal feeds, speeds, and tool paths are necessary.

Q: How much does GH3625 powder cost?

A: GH3625 typically costs between $90-250 per kg based on order size, particle size distribution, manufacturing method, and additional testing/qualification requirements. It is more expensive than stainless steel powders but lower cost than Inconel 718.

Conclusion

GH3625 is an advanced nickel-based superalloy designed specifically for additive manufacturing of high-performance components. It offers the advantages of both conventional alloys and AM-enabled design flexibility.

Carefully controlled powder characteristics and specialized parameter optimization allow exploiting the full potential of GH3625. With its properties and cost-effectiveness, GH3625 is emerging as a viable alternative to traditional alloys across critical aerospace, automotive, energy, and industrial applications.