Titanium and steel are often considered the top choices when selecting a strong metallic material for specific applications. Beyond their differences in strength, each metal has unique properties that make them suitable for various purposes. Which one is the right choice for your project? This article will provide an overview of these two metals and compare their major properties. Let's get started.
An Overview of Titanium
Titanium is a naturally occurring, nonmagnetic element with the chemical symbol Ti and atomic number 22 on the periodic table. It often exists in oxide forms, such as FeTiO3, and is found in various compounds and minerals. In the 1940s, William J. Kroll developed the Kroll process, which improved titanium extraction by reducing titanium tetrachloride with magnesium, making commercial production feasible.
Titanium is a silver-colored, lustrous transition metal with a high strength-to-weight ratio. It also offers excellent corrosion resistance and biocompatibility. Despite being a relatively new material compared to other metals, titanium has become essential in many applications, including aerospace, medical devices, automobile engines, marine equipment, industrial machinery, and jewelry, especially when cost is not a major concern.
While commercially pure (CP) titanium provides high corrosion resistance, its high melting point (1,668 ℃) makes it difficult to machine or process. Therefore, titanium alloys, often combined with other metals such as iron and aluminum, are more commonly used.
An Overview of Steel
Steel is an alloy of iron and carbon, along with trace amounts of other elements such as manganese, chromium, silicon, nickel, or tungsten. The earliest evidence of steel production dates back to around 1800 BC in Anatolia (modern-day Turkey). By around 1200 BC, the Iron Age began, and iron working spread across Europe and Asia, laying the groundwork for future advancements in steel production.
Despite its dense and robust nature, steel is remarkably malleable. It responds well to heat treatment to reinforce its structure and increase hardness. However, it is prone to corrosion, a challenge that stainless steel has overcome.
Steel can be classified based on various factors such as its chemical composition, microstructure, processing techniques, and intended uses. Common types of steel include carbon steel, alloy steel, stainless steel, and tool steel. As a more affordable alloy, steel is widely used in construction, machinery, automotive, home products and many other industries.
The Differences Between Titanium and Steel
Next, we will compare specific characteristics of titanium and steel to help you better understand their differences and make an informed choice.
Elemental composition & Crystalline structure
Titanium is a chemical element that is available in both pure and alloy forms. Commercially pure titanium primarily consists of titanium, with the composition of other elements, including nitrogen, hydrogen, oxygen, carbon, iron, and nickel, being between 0.013%~0.5%. Among titanium alloys, Ti-6Al-4V stands out as the most common, primarily comprising titanium along with aluminum and vanadium. In contrast, steel is an alloy primarily made of iron and carbon. The ratio of iron to carbon and the incorporation of various alloying elements result in a wide variety of steel types.
The crystalline structure of titanium and steel exhibits significant differences. Titanium adopts an HCP (hexagonal close-packed) structure, while steel possesses a BCC (body-centered cubic) structure. This fundamental distinction is one of the key factors contributing to titanium's lower density and its superior strength-to-weight ratio.
Weight
Titanium is nearly 43 % lighter than steel due to its lower density. With such a remarkable lightness and its strong property, titanium is a favorable material for aerospace applications.
In contrast, steel is strong but heavy. If light weight is not a priority, steel may be a better choice for many uses due to its lower cost.
Hardness
Overall, steel generally has superior hardness compared to titanium. While low-carbon steel has relatively low hardness, it is typically still higher than that of pure titanium. Certain titanium alloys, such as Ti-6Al-4V, exhibit higher hardness, reaching 30-35 on the Rockwell Hardness Scale (HRC). However, this is still lower than the hardness of some high-hardness steels, such as tool steels and quenched high-alloy steels, which can exceed 60 HRC.
Wear resistance
Pure titanium has relatively low wear resistance due to its lower hardness. While titanium alloys can be engineered to have reasonable wear resistance, they usually do not surpass that of high-hardness steels. These steels are often chosen for applications requiring high wear resistance, such as cutting tools, dies, and bearings. Titanium’s advantages lie more in its excellent strength-to-weight ratio, corrosion resistance, and biocompatibility.
Strength
Both titanium and steel are tough and able to withstand high stress, making them ideal for applications where high strength is a key factor. However, determining which material is stronger is not straightforward. The strength of titanium and various types of steel (such as stainless steel) varies depending on their composition, heat treatment, and manufacturing process.
Unalloyed titanium has a tensile strength similar to low-carbon steel. However, high-strength low-alloy steels generally have higher tensile and yield strengths than titanium. Despite this, titanium stands out for its lighter weight and typically better fatigue resistance.
Corrosion resistance
Titanium has superior corrosion resistance due to its protective oxide layer on its surface, which makes it highly resistant to corrosion. This oxide layer is self-healing, meaning that even if it is damaged to some extent, it can quickly restore its integrity through the self-healing mechanism, thus continuing to provide protective effects.
Steel is generally less corrosion-resistant than titanium. Although some types of steel, such as stainless steel, have improved corrosion resistance due to the addition of chromium, they cannot match the corrosion resistance of titanium.
Plasticity
Titanium has good plasticity, yet it falls behind steel in this aspect. This makes titanium more challenging to form and shape, particularly in its alloyed forms. Conversely, steel, especially in its low-carbon and alloy forms, exhibits remarkable resilience, enduring significant strains during deformation without fracturing. This makes steel easier to work with in a wide range of manufacturing processes, including bending, rolling, and drawing.
Conductivity (Electrical and Thermal)
Titanium has low electrical conductivity, only about 3.1% that of copper, making it a poor conductor of electricity. Steel, while having better electrical conductivity than titanium, is still a poor conductor compared to metals like copper and aluminum. The exact conductivity of steel varies with its composition; for example, carbon steel generally has lower conductivity than some alloy steels.
Thermally, titanium also has lower conductivity than steel, making it less efficient at transferring heat. Steel can dissipate heat more quickly due to its higher thermal conductivity, although it still lags behind metals like copper and aluminum in this regard.
Machinability
Titanium is difficult to machine primarily due to its low thermal conductivity, which leads to high temperatures at the cutting edge that can damage both the tool and the material. Additionally, titanium's tendency to work-harden—becoming harder in the area being cut—further complicates the process. Moreover, titanium can exhibit springback, slightly returning to its original shape after machining, which affects precision. Therefore, specialized tools and machining techniques are required to machine titanium effectively.
In contrast, steel generally has better machinability. Low carbon steel is relatively soft and easy to machine, while some alloy steels are designed to improve machinability by incorporating elements like sulfur or lead. Although stainless steel can be more challenging to machine than carbon steel, it is still more machinable than titanium.
Weldability
Steel exhibits better weldability than titanium. And it can be welded through common methods like Metal Inert Gas Welding (MIG) and Tungsten Inert Gas Welding (TIG). Titanium and its alloy are easy to be polluted by oxygen, nitrogen and hydrogen under high temperature. So its welding process requires stricter regulation and specialized tools. The adopted welding methods are gas tungsten arc welding (GTAW) and vacuum electron beam welding (VEBW).
Price
Titanium is significantly more expensive than steel. This higher cost is due to several factors. Firstly, titanium ore itself is more costly. Additionally, the processes involved in extracting and refining titanium are complex and energy-intensive. Furthermore, titanium's difficult machinability requires specialized tools and techniques, further driving up its price. In contrast, steel is a relatively inexpensive material due to the abundance of iron ore and simpler production processes.
Titanium vs. Steel：Which One to Choose?
Through the detailed comparison above, we now have a comprehensive understanding of the differences between titanium and steel. To help you choose the best metal for your needs more intuitively, you can quickly reference the table below to see their distinct advantages, limitations, and primary applications.
Advantages
Limitations
Primary Applications
Titanium
▪Excellent corrosion resistance ▪High strength-to-weight ratio ▪Ability to withstand extreme temperatures ▪Non-toxic element with good biocompatibility ▪Good fatigue resistance
▪High cost ▪Low elasticity and is readily deformed ▪Poor conductor of heat and electricity ▪Difficult in extracting, casting, and processing
▪Cost-effectiveness ▪High strength ▪Excellent weldability, machinability and is very easy and predictable to form ▪Sustainability
▪Susceptible to corrosion and rust (Stainless steel is not included.) ▪High Maintenance ▪Plain aesthetics
▪Construction and infrastructure ▪Vehicle components ▪Tools manufacturing ▪Oil and gas pipelines ▪heavy machinery ▪Kitchenware
The distinctive benefits of titanium and steel make them stand out among many other metals, leading to their widespread use. Given their cost-effectiveness and resource availability, steel often serves as a practical alternative to titanium, particularly in the following scenarios:
Cost is a major consideration.
Applications require metals that are easily workable, machinable, and weldable.
Large quantities of material are needed, as steel offers a wide range of alloy grades with specific properties.
However, titanium has several advantages that steel does not possess. Its lightweight nature and biocompatibility make it an ideal choice for applications such as medical implants and aerospace fasteners. Additionally, its exceptional corrosion resistance and high-temperature endurance make it superior in harsh environments.
The choice between using titanium and steel depends on balancing your project’s specific requirements and conducting a trade-off analysis considering cost, strength, weight, corrosion resistance, ease of fabrication, and alloy options.
Choose Your Best Partner
Depending on the specific demands of your design, you may have chosen one side in the titanium vs. steel debate. However, it's essential to strike a balance between the requirements of your project and the advantages and limitations of each metal before making a final decision. This process may seem trivial and can be complex. Don’t worry！Chiggo is here to guide you through it.
Chiggo provides custom manufacturing and fabrication services. Regardless of your order size, we can provide high-quality components with precise tolerances and excellent surface finishes. Contact us for guidance and professional advice on your design, manufacturing, and material usage.
Is Titanium Stronger than Steel?
Titanium exhibits exceptional strength-to-weight ratio, meaning it provides higher strength per unit mass compared to steel. However, when considering overall strength, steel remains the superior choice.
The strength properties of titanium and steel vary depending on the specific alloy composition and intended application. In some cases, titanium alloys can exceed the strength of certain grades of steel, making it a favorable material for applications where weight reduction is crucial, such as in aerospace engineering. Nonetheless, steel retains its position as a highly robust material for applications requiring maximum strength and durability.
