Inconel vs Titanium: Properties, Price, Strength

For components that must survive extreme heat, aggressive chemical attack or sustained creep, Inconel (nickel-chromium superalloys) is usually the better choice. For parts where low mass, high specific strength, corrosion resistance in many media, or biocompatibility matter, titanium alloys (especially Ti-6Al-4V / Grade 5) typically win. The correct selection depends on operating temperature, targeted strength-to-weight ratio, corrosion mode, manufacturability and cost.

Make the selection by answering three engineering questions:

• What is the peak and sustained service temperature? If the part spends time above ~400–500°C under load and creep or oxidation are concerns, favour Inconel alloys (many retain strength to 700–980°C depending on grade).

• Is weight critical? If low mass is a binding constraint (aerospace airframe, racing, portable devices), titanium alloys deliver much higher strength-to-weight ratios.

• Is biocompatibility or chloride resistance required? For implants and many marine/chemical service cases, titanium is usually preferable because of its passive oxide and proven biocompatibility; Inconel is favored in highly oxidizing or sulfurous high-temperature chemistries.

If two or more of these constraints bind simultaneously, a hybrid approach (bimetallic joints, coatings, or selective use of one metal for the hot zone and the other for structural parts) is often the right engineering compromise.

what is inconel and titanium mean?

• Inconel is a trademarked family name broadly applied to several nickel-chromium superalloys developed for turbine, chemical and nuclear service; common grades include Inconel 625 and 718. The trademark belongs to Special Metals and related technical bulletins describe composition and temperature limits for each alloy.

• Titanium metal and titanium alloys entered large-scale industrial use after powder metallurgy and Kroll-process improvements. Ti-6Al-4V (commonly called Ti-64 or Grade 5) became the industry workhorse for aerospace and medical parts because it balances low density with high strength.

Basic metallurgy and principal alloy families

• Inconel (nickel-based superalloys): nickel is the matrix element, strengthened by chromium, molybdenum, niobium (columbium) and sometimes cobalt or aluminium. These alloys are engineered for oxidation resistance, solid-solution strengthening and precipitation hardening (718 is age-hardenable). Composition differences explain why one Inconel grade is optimized for corrosion and another for high strength.

• Titanium alloys: elemental titanium is alloyed with aluminium, vanadium, molybdenum, iron and other elements to produce α, β or α-β microstructures. Ti-6Al-4V is an α-β alloy heat-treatable for strength and toughness; commercially pure grades (CP-Ti) trade off strength for ductility and corrosion performance.

Mechanical properties and specific strength

Notes on numbers: materials datasheets and industry handbooks report ranges depending on heat treatment and condition; the table shows representative, commonly cited values for Inconel 718 and Ti-6Al-4V (annealed/typical, Grade 5) to help engineering tradeoffs. Use manufacturer datasheets for final design values.

Key engineering takeaway: Inconel provides superior strength retention at elevated temperatures and excellent resistance to oxidation/crevice attack in many process chemistries; titanium delivers a powerful weight advantage and proven corrosion/biocompatibility for many wet environments.

High-temperature behaviour, creep and oxidation resistance

• Inconel alloys (e.g., 718, 625) are explicitly engineered for high-temperature service: many grades show excellent creep resistance, oxidation stability and maintain tensile strength much higher than titanium at temperatures above ~400–500°C. That makes them the default for gas-turbine hot sections, industrial heaters and chemical reactors exposed to hot corrosive gases.

• Titanium alloys lose strength rapidly beyond ~300–400°C and develop scale and embrittlement phenomena in some oxidizing atmospheres at elevated temperatures; their creep resistance is limited compared with nickel-based superalloys. For moderate temperatures where weight matters (airframe structure), titanium is ideal; for continuous high-temperature power-generation service, titanium is rarely used.

Corrosion behaviour and environments

• In aqueous and many oxidizing high-temp atmospheres: Inconel grades resist oxidation and pitting because of chromium and special alloying; 625 is particularly praised for aqueous corrosion resistance and resistance to pitting/chloride attack in many aggressive chemistries.

• Titanium: forms a very stable, protective oxide film that confers exceptional resistance to many corrosive media including seawater, chlorine and many acids. Titanium’s biocompatibility stems from that stable oxide. However, in strongly reducing, fluoride-containing or certain oxidizing high-temperature environments titanium can be attacked.

Practical rule: choose titanium for general aqueous and biomedical environments; choose Inconel for high-temperature oxidizing or sulfurous chemistries and where high creep resistance is required.

Inconel vs Titanium Price comparison 2025 (USD, approximate)

Quick conversions used: 1 kg = 2.20462 lb. Prices rounded to 2 significant figures for readability. (All ranges reflect supply/quality/region differences and are approximate as of Aug 26, 2025.)

Key takeaways

• On a per-kg basis, Inconel (especially high-grade 625/718 and powders) is generally more expensive than common titanium grades, because Inconel contains high shares of nickel, molybdenum and other costly alloying elements and often requires complex processing.

• Titanium Grade 5 (Ti-6Al-4V) often sits in a mid-range: cheaper than many Inconel finished products but more expensive than commercially-pure titanium (Grade 2).

• Scrap/recycle prices vary widely (condition, cleanliness and certification matter). Clean, segregated Inconel scrap can command high buy prices; mixed scrap is much lower.

• Powders (for additive manufacturing) are a big premium — both for Inconel and titanium — and should be budgeted separately.

Fabrication, welding and machining notes

• Welding: Many Inconel alloys are weldable with matching filler metals; 718 is age-hardenable and has well-established welding procedures, but post-weld heat treatment and process control are critical to prevent unwanted phases. Special Metals publishes welding and heat-treat guidance for common grades.

• Titanium welding: titanium welding requires rigorous cleanliness, inert shielding (argon) and control of interstitial contamination (oxygen, nitrogen). Titanium welding specialists and controlled atmospheres are standard. ASTM specifications (e.g., B348 for bars) define acceptable product and process conditions.

• Machining: Both materials are difficult to machine versus steels and aluminum. Inconel work-hardens quickly and can cause tool wear; Ti-6Al-4V is gummy, causes tool chatter, and adheres to cutting edges. Machining strategies differ: Inconel benefits from rigid set-ups, high-temperature carbide or ceramic tooling and conservative feeds; titanium needs low cutting speeds, high rigidity and cooling to avoid built-up edge. Comparative machining studies document significantly higher cutting forces on Inconel 718 vs Ti-6Al-4V under many conditions.

Thermal, electrical and physical properties that affect design

• Thermal expansion and conductivity: Both metals have relatively low thermal conductivity; titanium’s low conductivity concentrates thermal gradients, while Inconel’s slightly higher conductivity eases some thermal stress—still, both require thermal stress analysis in high heat-flux applications.

• Modulus difference: Titanium’s modulus (~110–120 GPa) is much lower than Inconel/steels (~200 GPa), which influences stiffness, natural frequency and deflection under load. Designs requiring stiffness per unit volume must account for that (use larger sections or composite hybrids).

Standards and authoritative specifications

When specifying material and accepting suppliers, refer to authoritative standards:

• Inconel (family): manufacturer datasheets and UNS/EN/ASTM designations (e.g., UNS N07718 for 718, UNS N06625 for 625). Manufacturer technical bulletins (Special Metals) are primary reference documents for composition and heat treatment.

• Titanium: ASTM specifications such as ASTM B348 (bars and billets for Ti-6Al-4V), ASTM F67/F136 for implant grades, and AMS/AMS-STD product specifications. Use these to document mechanical test acceptance and chemical limits.

Typical industry applications and a usage matrix

Cost, supply chain and lifecycle tradeoffs

• Raw material cost: both Inconel and titanium are more expensive than common steels and aluminum. Nickel superalloys often have high alloying element cost (niobium, molybdenum), while titanium production (Kroll + melt + processing) keeps unit price elevated. Market swings in nickel, vanadium and scrap influence prices. For many designs, lifecycle cost (maintenance, downtime, replacement interval) outweighs raw material cost.

• Processing cost: machining and welding difficulties increase fabrication cost; titanium’s cleanliness requirements and Inconel’s tooling-wear penalties must be budgeted. Coatings (thermal barrier or corrosion liners) or bimetallic joints add cost but can unlock hybrid performance.

Design & engineering selection checklist

1. Define maximum continuous operating temperature and peak transient temperature.

2. Identify dominant corrosion mechanism (chloride pitting, sulfur attack, fluoride, biological).

3. Choose candidate grades (e.g., Inconel 625 or 718; Ti-6Al-4V or CP-Ti) and obtain full datasheets.

4. Check manufacturability: welding specification, supplier capabilities, expected tolerances.

5. Run finite element analysis for thermal gradients, creep and fatigue at service temperature.

6. Validate with small-scale tests: corrosion coupons, weld trials, creep tests where necessary.

7. Document procurement with the correct ASTM/UNS/AMS/EN spec and certificates of analysis.

FAQs

1. Which metal is stronger — Inconel or titanium?
Strength depends on the specific grade and temperature. At room temperature both can have comparable tensile strengths (heat-treated Inconel 718 may show higher values), but Inconel retains strength much better at high temperatures whereas titanium’s strength drops off above ~300–400°C.

2. Which metal is lighter?
Titanium is roughly 45–55% lighter by density (≈4.4 g/cm³) than nickel superalloys (≈8.1 g/cm³). This gives titanium a major advantage in mass-sensitive designs.

3. Are titanium implants safer than Inconel?
Yes — titanium alloys (Grade 5, CP-Ti) are widely accepted for implants due to biocompatibility and stable oxide. Nickel-based alloys can provoke allergic responses in some patients, so they are rarely used for permanent implants.

4. Which is more corrosion resistant in seawater?
Titanium generally resists seawater corrosion very well thanks to its passive oxide. Certain Inconel grades also resist marine corrosion but titanium is often preferred when lifecycle cost can justify the initial price.

5. Can I weld both materials easily?
Both can be welded, but each has special needs: Inconel’s welding must handle age-hardening and avoid unwanted phases; titanium welding requires strict inert shielding to prevent contamination. Use qualified weld procedures and experienced welders.

6. What about fatigue performance?
Fatigue behaviour depends heavily on surface finish, temperature and environment. Inconel can have excellent high-temperature fatigue life; titanium performs well for cyclic loads at ambient and moderate temperatures when designed to avoid stress concentrations. Always use application-specific data.

7. Which is cheaper?
Price varies with market but both are expensive relative to carbon steels. Processing, machining and finishing often drive the majority of component cost. Obtain quotes for raw material and fabrication early in the design cycle.

8. Can I use coatings to combine benefits?
Yes. Coatings, thermal barriers, or cladding can let a cheaper substrate support a corrosion- or heat-resistant overlay. Bimetallic joints (friction welding, explosion bonding) are common solutions to pair titanium and Inconel where each metal’s strengths are needed in different zones.

9. Are there alloy substitutes that mimic both properties?
No single metal matches both Inconel’s high-temperature creep strength and titanium’s low density simultaneously. Advanced composites or directionally solidified superalloys and ceramic matrix composites are used where neither metal suffices.

10. What test certificates or supplier documents should I require?
Require chemical composition (C of A), mechanical test reports, heat-treatment records and conformance to ASTM/AMS/UNS/EN specifications specified in the purchase order. For critical parts, request traceability to melt lot and non-destructive testing where appropriate.