Raw Materials Used in Engines: What Powers the World’s Prime Movers

Engines are built from a core palette of metals and advanced materials: iron and steel for strength, aluminum and magnesium for lightness, copper for conductivity, nickel- and titanium-based alloys for high temperatures, ceramics for sensing and heat protection, polymers and elastomers for sealing, and specialty elements such as platinum-group metals and rare earths in select components. Below is a clear breakdown of what goes into internal combustion engines and gas turbines, with context on modern hybrids and supply trends.

What “Raw Materials” Means in Engine Manufacturing

In industry, “raw materials” usually refers to the base substances—metals, polymers, ceramics, and composites—before they are cast, forged, machined, or coated into finished parts. For engines, that spans ferrous alloys (steels, cast irons), non-ferrous alloys (aluminum, magnesium, copper), high-temperature superalloys, engineered ceramics, and elastomers, plus small but critical amounts of precious or rare elements for catalysts, sensors, and magnets.

Core Materials by Engine Type

Internal Combustion Engines (Gasoline/Diesel)

Road and off-highway engines rely on a mix that balances durability, weight, cost, and heat resistance. The materials below are typical for blocks, heads, rotating assemblies, turbochargers, fuel systems, and aftertreatment.

• Ferrous alloys: gray and compacted graphite iron (CGI) for blocks and liners; alloy steels for crankshafts, camshafts, gears, and fasteners.
• Aluminum alloys (often Al-Si): cylinder heads, many passenger-car blocks, pistons, and compressor housings to reduce mass.
• Magnesium alloys: limited use for covers and housings where ultralight weight helps, with careful heat and corrosion management.
• Copper and copper alloys: windings (e.g., alternators), wiring, busbars, and bronze/brass in bearings, bushings, and heat exchangers.
• Nickel-based alloys: turbocharger turbine wheels, exhaust valves and seats in high-heat duty, and exhaust manifolds for durability.
• Titanium alloys: high-performance valves and connecting rods where strength-to-weight is critical.
• Polymers and composites: thermoplastics (PA66, PBT, PPS, PEEK) for covers, manifolds, fuel rails; fiber-reinforced plastics for intake systems.
• Elastomers and seals: NBR (nitrile), FKM (Viton), silicone, and PTFE for gaskets, O-rings, and shaft seals resistant to oils and fuels.
• Ceramics: zirconia in oxygen (lambda) sensors; silicon nitride in some rolling elements; alumina in spark plug insulators.
• Coatings and surface treatments: nitriding, DLC (diamond-like carbon) on tappets and rings, hard chromium or PVD on piston rings.
• Aftertreatment catalysts: platinum, palladium, and rhodium on ceramic (cordierite) or metallic substrates for emissions control; ceria-zirconia as oxygen storage.

Together, these materials enable engines to manage wear, friction, heat, corrosion, and emissions while keeping weight and cost within target.

Gas Turbines and Jet Engines

Aero and industrial turbines operate at extreme temperatures and stresses, pushing materials technology to its limits. The following are foundational to compressors, combustors, and turbines.

• Nickel-based superalloys (e.g., Inconel, René, CMSX series): single-crystal or directionally solidified blades and vanes with elements like chromium, cobalt, aluminum, tantalum, and rhenium for creep resistance.
• Cobalt-based alloys (e.g., Stellite): wear- and heat-resistant coatings and some hot-section parts.
• Titanium alloys (e.g., Ti-6Al-4V): fan and compressor stages where high strength-to-weight and moderate temperature capability are needed.
• Steels (martensitic and bearing grades): shafts, gears, cases, and bearings (e.g., M50) where toughness and fatigue life matter.
• Ceramic matrix composites (SiC/SiC): hot-section shrouds, combustor liners, and some vanes for weight saving and temperature capability.
• Thermal barrier coatings: yttria-stabilized zirconia (YSZ) over MCrAlY bond coats to insulate superalloy airfoils.
• Polymer-matrix composites and carbon fiber: large-diameter fan blades and cases in many modern turbofans; honeycomb and abradable seals.
• Specialty elements: rhenium (in some blade alloys), hafnium, and tungsten for high-temperature performance and balancing weights.

This combination allows turbines to run hotter and lighter, improving efficiency and thrust while maintaining safety margins.

Electric Drive Units and Hybrids (Powertrain Context)

While strictly speaking motors are not “engines,” hybrid powertrains pair engines with electric machines. Materials below are increasingly relevant in integrated engine–motor systems.

• Electrical steels (silicon steel): stator and rotor laminations for motors and generators.
• Copper (or aluminum): windings, rotors, busbars, and heat exchangers for electrical conductivity and thermal management.
• Permanent magnets: Nd-Fe-B with dysprosium/terbium for high-temperature grades; ferrites in magnet-free designs are an alternative.
• Power electronics materials: silicon and silicon carbide (SiC) devices; substrates like AlN and Al2O3; solders, silver sinter, and encapsulants.
• Polymers and insulation: epoxies, polyimide films, slot liners, and potting compounds; advanced lubricants compatible with e-motors.

These additions reflect the industry’s shift toward electrified powertrains, where engines coexist with high-efficiency electric machines.

Materials by Function and Component

The same engine may mix materials across components to meet localized demands of heat, stress, and friction. Here’s a functional mapping of common choices.

• Blocks and liners: gray iron or CGI for strength and wear; aluminum blocks with cast-in or coated iron liners for weight savings.
• Cylinder heads: aluminum alloys (high thermal conductivity) with hardened valve seats and guides (sintered iron/cobalt alloys).
• Pistons and rings: hypereutectic Al-Si pistons with anodized or graphite coatings; steel or cast-iron rings with Cr, Mo, or DLC coatings.
• Crankshafts and connecting rods: forged alloy steels; powder-forged rods in high-volume applications; titanium rods in racing.
• Camshafts and valvetrain: chilled cast iron or steel cams; austenitic and martensitic stainless steels for valves, sometimes sodium-filled.
• Turbochargers: nickel superalloy turbine wheels and housings; aluminum or titanium compressor wheels; high-temperature bearings and seals.
• Fuel and ignition: stainless steels and polymers in injectors and rails; iridium/platinum-tipped spark plugs.
• Sensors and controls: zirconia (O2 sensors), PZT ceramics (knock sensors), silicon (ECUs), and gold/precious metals in connectors.
• Gaskets and seals: multi-layer steel (MLS) head gaskets; graphite, aramid fiber, and elastomeric seals (NBR, FKM, PTFE) throughout.
• Lubricants and coolants: base oils (mineral/synthetic) with additive packages (ZDDP, detergents, dispersants); glycol-based coolants with corrosion inhibitors.
• Exhaust and aftertreatment: stainless steels for manifolds; cordierite/SiC substrates with Pt/Pd/Rh catalysts; urea (DEF) systems for diesels.

This component-level view highlights how each material is chosen for a specific role—strength in the bottom end, heat resilience in the hot side, and chemical resistance in sealing and emissions control.

Forms and Manufacturing Routes

Raw materials reach final parts through specific processes that influence performance and cost. The routes below are typical for engine hardware.

• Castings: sand and die-cast aluminum blocks/heads; gray/CGI iron blocks; investment-cast turbine blades and housings.
• Forgings: steel crankshafts, connecting rods, gears, and turbine/compressor disks for fatigue strength.
• Powder metallurgy: sintered valve seats/guides, gears, and PM connecting rods; hot isostatic pressing (HIP) for superalloy components.
• Additive manufacturing: laser powder-bed or DED in Inconel 718, Ti-6Al-4V, and AlSi10Mg for complex cooling passages and rapid iteration.
• Sheets, tubes, and extrusions: stainless exhausts, heat exchangers, fuel lines, and structural housings.
• Surface engineering: nitriding, carburizing, PVD/CVD coatings, and thermal spray (including TBCs) to manage wear and heat.

Process selection is as critical as material selection, often determining fatigue life, thermal tolerance, and manufacturability.

Supply, Sustainability, and Regulation (2024–2025)

Global sourcing and environmental rules shape which materials are used and how. The following dynamics are guiding current choices and substitutions.

• Recycled content: iron and aluminum castings typically incorporate high scrap fractions, cutting cost and CO2; closed-loop foundry recycling is common.
• Critical materials: nickel, cobalt, titanium, platinum-group metals, rare earths (Nd, Dy), and rhenium face supply concentration; diversification and thrift are priorities.
• Substitution trends: steel piston rings replacing chromium plating; platinum/palladium mix adjusted to price and emissions targets; magnet-free motor designs to reduce rare-earth dependency.
• Chemical regulation: PFAS restrictions under discussion in the EU could affect some fluoroelastomer seals; industry is pursuing derogations for essential high-temperature uses.
• Lifecycle focus: OEMs increasingly specify lower-CO2 aluminum/steel, lead-free bearing alloys, and design for recyclability to meet corporate and regulatory targets.

Material strategies now balance performance with security of supply and environmental compliance, often driving rapid innovation in coatings and component design.

Quick Reference: Typical Material Mix by Mass

Actual percentages vary by design and duty cycle, but the distributions below offer a useful rule of thumb for common engine types.

• Passenger-car ICE engine: roughly 55–70% ferrous alloys; 10–25% aluminum; 1–3% copper; up to 2% magnesium; 5–10% polymers/elastomers; trace precious/rare elements in sensors and catalysts.
• Modern turbofan core: approximately 40–60% nickel-based superalloys; 15–30% titanium; 5–15% steels; 5–15% polymer/composite structures; <1% specialty elements (e.g., rhenium, hafnium); small but vital ceramic coatings.

These ranges reflect design trade-offs: automotive engines prioritize cost and weight reduction, while turbines emphasize high-temperature capability and efficiency.

Summary

Engines are multi-material systems. Iron and steel anchor strength and cost; aluminum and magnesium trim weight; copper enables electrics and thermal control; nickel- and titanium-based alloys survive the hottest zones; ceramics sense and shield; polymers and elastomers seal and simplify. Layered on top are critical but tiny quantities of precious and rare elements that enable emissions control and high-efficiency operation. As regulations tighten and supply chains shift, the mix continues to evolve—but the core materials above remain the backbone of engine design and manufacturing.

Is there gold in engines?

Engine Control Units (ECUs)
This is where gold and silver come in. These metals are used in the microprocessors and circuit boards within the ECU. Gold and silver are excellent at conducting electricity. They also don’t rust or corrode easily.

What materials are engines made of?

Engines are made from a combination of metals like cast iron, aluminum alloys, and steel, with the specific materials chosen based on factors like cost, weight, strength, and heat tolerance. The engine block is typically cast from either iron or aluminum, while internal components such as the crankshaft, connecting rods, and camshafts are often made of durable steel alloys. Other parts may use lighter materials like advanced polymers for covers and hoses or exotic metals for specialized components like exhaust valves. 
Common Engine Materials

• Cast Iron: Opens in new tabUsed for its strength, low cost, and ability to withstand high temperatures and pressures. It’s a traditional choice for engine blocks and other heavy-duty components. 
• Aluminum Alloys: Opens in new tabChosen for their lighter weight, which improves fuel efficiency and vehicle performance. Aluminum is widely used for engine blocks, cylinder heads, and pistons in modern vehicles. 
• Steel: Opens in new tabA crucial material for components requiring high tensile strength, such as the crankshaft, connecting rods, and valve train parts. 
• Advanced Polymers and Composites: Opens in new tabUsed for lightweight covers, manifolds, and hoses to further reduce overall engine weight. 
• Exotic Metals: Opens in new tabSuch as titanium or specialized high-temperature alloys, are sometimes used for critical components like valves in high-performance or specialized engines due to their unique properties. 

Material Selection Factors
Engineers balance different material properties to optimize engine design: 

• Weight: Lighter materials like aluminum improve fuel economy and handling. 
• Strength: Essential for handling the intense pressure and stresses within an engine’s combustion chamber and rotating assembly. 
• Durability: Cast iron’s robustness contributes to a longer lifespan, while aluminum’s lighter density is a trade-off. 
• Cost: The price of materials significantly influences choices for mass-produced engines. 
• Heat Resistance: Some metals are better suited to withstand the high operating temperatures of an engine. 

What are the raw materials of a motor?

In conclusion, electric motors rely on a variety of materials to function properly. Copper and steel are commonly used for the motor’s electromagnetic coils and core, while aluminum is used for the rotor. Magnets, insulation materials, and bearings are also essential components of electric motors.

What are the raw materials for the automotive industry?

Steel, rubber, plastics, and aluminum are the four most common commodities found in cars. The auto industry relies heavily on petroleum products, not just for gasoline for autos with internal combustion engines (ICE), but for synthesizing plastics and other synthetic materials.