Due to their special qualities, steel and titanium are two of the metals that are employed in a wide range of sectors. Each metal has benefits and drawbacks, and they work well in certain contexts.
We shall compare these two metals in-depth in this post, detailing their unique qualities, benefits, and drawbacks as well as how to pick the best metal for your purpose.
Alloy titanium
One significant structural metal that was created in the 1950s is titanium. Because of its great strength, excellent resistance to corrosion, and high heat resistance, titanium alloys are widely used in many different sectors. The primary focus of titanium alloy development in the 1950s was on structural titanium alloys for aircraft bodies and high-temperature titanium alloys for aircraft engines. Numerous titanium alloys resistant to corrosion were created in the 1970s. High-strength and corrosion-resistant titanium alloys have been developed further since the 1980s. Titanium alloys are mostly utilized to create compressor parts for aviation engines, then missiles, rockets, and high-speed aircraft structural elements.
Stainless steel
Steel that is resistant to corrosion by chemically corrosive media like acids, alkalis, and salts as well as weakly corrosive media like air, steam, and water is referred to as stainless steel. Another name for it is acid-resistant stainless steel. Steel that can withstand corrosion from weak corrosive media is commonly referred to as stainless steel in practical applications, whereas steel that can withstand corrosion from chemical media is called acid-resistant steel. The former is not always resistant to corrosion by chemical media, whereas the latter is typically stainless due to their different chemical compositions. The alloying elements that are present in stainless steel determine its resistance to corrosion. In order to meet the requirements of stainless steel organization and performance for varied uses, basic alloying components of stainless steel include nickel, molybdenum, titanium, niobium, copper, nitrogen, etc.
Ten main characteristics of titanium
1. Elevated specific strength and minimal density
Titanium metal has the highest specific strength of any metal at 4.51g/cm3, which is lower than that of steel, copper, and nickel and higher than that of aluminum.
2. Resistance to corrosion
With a very low equilibrium potential and a strong propensity for thermodynamic corrosion in the medium, titanium is an extremely active metal. However, titanium is actually quite stable in a wide range of media. For example, it resists corrosion in oxidizing, neutral, and slightly reducing environments. This is a result of the strong affinity between titanium and oxygen. A thick, extremely sticky, and inert oxide layer forms on the surface of titanium when exposed to air or other oxygen-containing fluids, shielding the titanium matrix from corrosion. It can be mechanically worn, but it will regenerate or heal swiftly. This demonstrates titanium’s significant passivation tendency as a metal. This property of the titanium oxide coating is unaffected by temperature changes below 315°C.
The protective effect of titanium oxide film has been studied in order to obtain the desired corrosion resistance through surface treatment technologies such as oxidation, electroplating, plasma spraying, ion nitriding, ion implantation, and laser treatment. Titanium-molybdenum, titanium-palladium, and titanium-molybdenum-nickel are among the corrosion-resistant titanium alloys that have been developed in response to the need for metal materials in the production of sulfuric acid, hydrochloric acid, methylamine solution, high-temperature wet chlorine gas, and high-temperature chloride. All titanium alloys have shown good results; titanium-32 molybdenum alloy is utilized in titanium castings; titanium-0.3 molybdenum-0.8 nickel alloy or titanium-0.2 palladium alloy is used in components of titanium equipment for settings where pitting or crevice corrosion is common.
3. Strong resistance to heat
While new titanium alloys can have good mechanical qualities at 600°C or greater, aluminum often loses its original performance at 150°C and stainless steel around 130°C. Titanium alloys must be utilized in place of aluminum and magnesium alloys when the aircraft exceeds 2.7 times the speed of sound and the surface temperature of the aircraft structure hits 230°C.
Due to its high heat resistance, titanium can be utilized in aircraft engines, rear fuselages, and other areas where engine heat dissipation is a concern.
4. Strong resilience to low temperatures
Titanium alloys TA7 (Ti-5Al-2.5Sn), TC4 (Ti-6Al-4V), and Ti-2.5Zr-1.5Mo are examples of low-temperature titanium alloys whose strength rises with decreasing temperature but their fluidity remains relatively constant. Even at -196-253°C, it retains good ductility and toughness, preventing metal cold brittleness. It is a perfect material for tanks, containers, and other equipment on manned spacecraft that must withstand extremely low temperatures. It can also be utilized in liquid nitrogen and liquid oxygen rocket engines.
5. Excellent performance against dampening
In contrast to steel and copper, titanium exhibits the longest self-vibration attenuation period following mechanical and electrical vibration exposure. Tunning forks, vibration components of medical ultrasonic pulverizers, and vibration films of high-end audio speakers can all be made using titanium thanks to its useful feature.
6. Unique properties, non-toxic, and non-magnetic properties of titanium and alloys
Even under strong magnetic fields, titanium is a non-magnetic metal that will not get magnetized. It is employed in the medical profession since it is non-toxic and has good compatibility with human blood and tissue.
1. Memory performance
When exposed to specific temperatures, TiNi alloy can regain its former shape.
2. Function of superconductivity
Superconductivity of NbTi alloy is present at a certain low temperature.
3. Function of hydrogen absorption
The TiFe alloy has a high hydrogen absorption capacity. This characteristic makes it possible to store hydrogen securely.
7. The relationship between tensile and yield strengths
This titanium feature indicates that the metal exhibits poor plastic deformation while forming because of its high yield strength ratio (tensile strength/yield strength). Titanium has a high rebound ability during forming because of the significant ratio between its elastic modulus and yield limit.
8. Effective heat transfer
Titanium has a lesser thermal conductivity than carbon steel and copper, but because of its superior resistance to corrosion, wall thickness can be significantly decreased. Additionally, heat transmission from the surface to steam occurs through droplet condensation, which lowers the heat group. Titanium performs much better in heat transfer when there is no scaling on the surface, which can also lower thermal resistance.
9. Low elastic modulus
The elastic modulus of titanium is 106.4GMPa at room temperature, which is 57% of that of steel. 10. Performance during inhalation
The metal titanium has extremely active chemical characteristics. At high temperatures, it can react with a wide range of elements and compounds. The reaction of titanium with carbon, hydrogen, nitrogen, and oxygen at high temperatures is primarily referred to as titanium inhalation.
The properties of stainless steel are as follows:
The following are the characteristics of stainless steel:
1.Chemical properties: Titanium alloys outperform all other steels in terms of chemical and electrochemical corrosion resistance.
2. Physical characteristics include resistance to heat, high, low, and even ultra-low temperatures.
3. Mechanical properties: Mechanical properties vary according to different types of stainless steel. Martensitic stainless steel has high strength and hardness, and is suitable for manufacturing parts that are both corrosion-resistant and require high strength and high wear resistance, such as turbine shafts, stainless steel knives, stainless steel bearings, etc. Austenitic stainless steel has good plasticity, not too high strength, but the best corrosion resistance among stainless steels. It is suitable for occasions that require very high corrosion resistance but not high mechanical properties, such as chemical plants, fertilizer plants, sulfuric acid, hydrochloric acid manufacturers, etc. Equipment materials, of course, can also be used in military industries such as submarines. Ferritic stainless steel has moderate mechanical properties, not too high strength, but oxidation resistance, suitable for various industrial furnace parts.
4. Process performance: Austenitic stainless steel has the best process performance. Due to its good plasticity, it can be processed into various plates, tubes and other profiles, and is suitable for pressure processing. Martensitic stainless steel has poorer process performance due to its high hardness.
Comparing titanium and stainless steel properties
Density
• Titanium is a pure elemental metal with exceptional strength and light weight. Compared to stainless steel, it is substantially lighter with a density of 4.51 g/cm³.
• The main constituents of stainless steel, on the other hand, are iron, chromium (at least 10.5% for corrosion resistance), and other elements. Because of its density, which varies from 7.70 to 7.90 g/cm³, it is around 50% heavier than titanium.
Power and Sturdiness
• Tensile Strength: Titanium is less likely to break under stress than stainless steel because it has a higher tensile strength. At a small fraction of the weight, it is roughly 30% stronger than steel.
• Durability: Despite titanium’s strength, it can be more prone to scratches. Stainless steel, on the other hand, is generally more impact and scratch resistant.
Corrosion Resistance:
• Titanium’s ability to develop a protective oxide layer that keeps rusting makes it exceptionally resistant to corrosion, especially in hostile situations.
• While stainless steel also resists corrosion well, it is not as effective in harsh environments as titanium. Although stainless steel can corrode in some situations (such as when exposed to saltwater), chromium helps prevent rusting.
Temperature Resistance:
Titanium can withstand temperatures up to 1,660°C, which makes it a better material for high-temperature applications like aircraft components than stainless steel, which has a melting point between 1,416 and 1,537°C.
Cost and Machinability
• Cost: Titanium is significantly more expensive than stainless steel—up to five times more costly for equivalent parts—due to its extraction and processing complexities.
• Machinability: Stainless steel is generally easier and cheaper to machine than titanium. Titanium requires specialized tools and techniques due to its tendency to gall (stick) during machining.
Applications:
•Because titanium is lightweight and biocompatible, it is frequently utilized in high-performance automotive, aerospace, and medical implants.
• Due to its affordability, strength, and durability, stainless steel is used extensively in industrial applications, kitchenware, and construction.
In summary
Selecting between stainless steel and titanium primarily depends on the particular needs of your project:
• Titanium is a preferable material if you prioritize weight reduction, greater corrosion resistance, and high strength—and budget is less of an issue.
Conversely, stainless steel would be a better choice if lower costs, simpler manufacture, and increased impact resistance are required.
Knowing these qualities will enable you to choose wisely depending on the requirements of your project.