Content Menu
● Introduction
● Understanding Hardness
>> Definition of Hardness
>> Measuring Hardness
>>> Mohs Scale
>>> Vickers Hardness Test
● Tungsten Carbide: Properties and Characteristics
>> Composition and Structure
>> Hardness of Tungsten Carbide
>> Applications of Tungsten Carbide
● Diamond: The Hardest Natural Substance
>> Formation and Structure
>> Hardness of Diamond
>> Applications of Diamond
● Comparing Tungsten Carbide and Diamond
>> Hardness Comparison
>> Other Property Comparisons
>>> Toughness
>>> Thermal Conductivity
>>> Cost
● Applications Where Hardness Matters
>> Industrial Cutting Tools
>> Drilling Equipment
>> Wear-Resistant Coatings
>> Jewelry
● Factors Influencing Hardness
>> Purity and Composition
>> Crystal Orientation
>> Manufacturing Process
● Misconceptions About Hardness
>> Hardness Equals Indestructibility
>> Hardness is the Only Important Property
>> All Diamonds are Equally Hard
● Future Developments
>> Synthetic Super-Hard Materials
>> Nanocomposites
● Conclusion
● FAQ
>> 1. Can tungsten carbide scratch a diamond?
>> 2. Why is tungsten carbide used instead of diamond in some applications?
>> 3. Are there any materials harder than diamond?
>> 4. How does the cost of tungsten carbide compare to diamond?
>> 5. Can tungsten carbide be used in jewelry like diamonds?
● Citations:
Introduction
The world of materials science is filled with fascinating substances, each boasting unique properties that make them suitable for various applications. Among these, tungsten carbide and diamond stand out as two of the hardest materials known to mankind. Both have garnered significant attention for their exceptional hardness and durability, leading to widespread use in industrial and consumer applications. However, a common question often arises: Is tungsten carbide harder than diamond? This article aims to explore this query in depth, comparing the properties of these two remarkable materials and shedding light on their respective strengths and applications.
Understanding Hardness
Before delving into the comparison between tungsten carbide and diamond, it's crucial to understand what we mean by "hardness" in materials science.
Definition of Hardness
Hardness is a measure of a material's resistance to localized deformation, typically caused by indentation or scratching. It's an important property that determines how well a material can withstand wear and tear, as well as its suitability for various applications.
Measuring Hardness
Several scales are used to measure hardness, with the Mohs scale and the Vickers hardness test being among the most common.
Mohs Scale
The Mohs scale, developed in 1812 by German mineralogist Friedrich Mohs, rates the hardness of materials on a scale from 1 to 10. Each number represents the ability of a material to scratch materials rated lower on the scale.
Vickers Hardness Test
The Vickers hardness test provides a more precise measurement of hardness. It involves pressing a diamond-shaped indenter into a material with a known force and measuring the size of the resulting indentation.
Tungsten Carbide: Properties and Characteristics
Tungsten carbide is a compound of tungsten and carbon atoms in a 1:1 ratio. It's known for its exceptional hardness and wear resistance, making it a popular choice for various industrial applications.
Composition and Structure
Tungsten carbide typically consists of tungsten carbide grains held together by a binder material, often cobalt. This composition gives it a unique combination of hardness and toughness[1].
Hardness of Tungsten Carbide
On the Mohs scale, tungsten carbide rates between 8.5 and 9.5, depending on its exact composition[2]. This places it among the hardest known materials, second only to a few substances including diamond.
Applications of Tungsten Carbide
Due to its hardness and wear resistance, tungsten carbide finds use in:
1. Cutting tools for metalworking
2. Mining and drilling equipment
3. Wear-resistant components in machinery
4. Jewelry and watch-making
Diamond: The Hardest Natural Substance
Diamond, an allotrope of carbon, is renowned as the hardest naturally occurring substance on Earth.
Formation and Structure
Diamonds form deep within the Earth under extreme pressure and temperature conditions. Their crystal structure, with each carbon atom bonded to four others in a tetrahedral arrangement, contributes to their exceptional hardness[7].
Hardness of Diamond
Diamond sits at the top of the Mohs scale with a rating of 10. On the Vickers scale, diamond can have a hardness value of up to 10,000 HV, though this can vary depending on the specific diamond[7][18].
Applications of Diamond
Diamonds are used in:
1. Cutting and grinding tools
2. High-pressure experiments
3. Jewelry
4. Certain electronic applications
Comparing Tungsten Carbide and Diamond
Now that we've explored the properties of both materials, let's directly compare tungsten carbide and diamond in terms of hardness and other relevant characteristics.
Hardness Comparison
While both materials are exceptionally hard, diamond is indeed harder than tungsten carbide. On the Mohs scale, diamond rates a 10, while tungsten carbide typically rates between 8.5 and 9.5[2][7].
Other Property Comparisons
Toughness
While diamond is harder, tungsten carbide is generally tougher. Toughness refers to a material's ability to absorb energy before fracturing. Tungsten carbide's composite structure of hard carbide grains in a tough metal binder gives it superior toughness compared to diamond[1][18].
Thermal Conductivity
Diamond has a higher thermal conductivity than tungsten carbide. This property makes diamond excellent for heat dissipation in cutting tools[18].
Cost
Tungsten carbide is generally less expensive than diamond, making it a more cost-effective choice for many applications where extreme hardness is required but diamond-level hardness isn't necessary[21].
Applications Where Hardness Matters
The extreme hardness of both tungsten carbide and diamond makes them valuable in various applications where wear resistance is crucial.
Industrial Cutting Tools
Both materials are used in cutting tools, but for different purposes. Tungsten carbide is often used for metal cutting, while diamond is preferred for cutting extremely hard materials like ceramics or other diamonds[24].
Drilling Equipment
In the oil and gas industry, both materials are used in drill bits. Diamond is often used in the form of polycrystalline diamond compact (PDC) bits for drilling through hard rock formations[4].
Wear-Resistant Coatings
Both materials can be used as coatings to improve the wear resistance of various components. Diamond-like carbon (DLC) coatings are particularly popular in some applications[18].
Jewelry
While diamonds are traditionally used in fine jewelry, tungsten carbide has gained popularity in recent years for men's wedding bands due to its durability and scratch resistance[16].
Factors Influencing Hardness
It's important to note that the hardness of both tungsten carbide and diamond can vary depending on several factors:
Purity and Composition
For tungsten carbide, the ratio of tungsten to carbon and the type and amount of binder material used can affect its hardness. For diamonds, the presence of impurities or defects in the crystal structure can influence hardness[1][18].
Crystal Orientation
In diamonds, hardness can vary slightly depending on the crystal orientation. Some directions within the crystal are slightly harder than others[18].
Manufacturing Process
For synthetic diamonds and tungsten carbide, the manufacturing process can influence the final hardness. Factors like sintering temperature and pressure can affect the properties of the final product[6].
Misconceptions About Hardness
There are several common misconceptions about material hardness that are worth addressing:
Hardness Equals Indestructibility
While both tungsten carbide and diamond are extremely hard, neither is indestructible. Both can be broken or chipped with sufficient force[10][18].
Hardness is the Only Important Property
While hardness is crucial for many applications, other properties like toughness, thermal conductivity, and cost are often equally important when choosing a material for a specific use[21][24].
All Diamonds are Equally Hard
Natural diamonds can vary in hardness depending on their formation conditions and the presence of impurities. Some synthetic diamonds have even been created that are harder than natural diamonds[13].
Future Developments
Research in materials science continues to push the boundaries of what's possible in terms of material hardness:
Synthetic Super-Hard Materials
Scientists are working on developing new synthetic materials that could potentially surpass diamond in hardness. Materials like wurtzite boron nitride and lonsdaleite (hexagonal diamond) show promise in this area[17].
Nanocomposites
Researchers are exploring nanocomposite materials that combine the hardness of materials like diamond or tungsten carbide with the toughness of other materials, potentially creating substances with an optimal balance of properties[6].
Conclusion
In conclusion, while tungsten carbide is indeed one of the hardest materials known to man, it is not harder than diamond. Diamond remains the hardest naturally occurring substance, with a Mohs hardness of 10 compared to tungsten carbide's 8.5-9.5. However, this doesn't mean that diamond is always the better choice for all applications. Tungsten carbide's combination of extreme hardness and superior toughness makes it ideal for many industrial and consumer applications where diamond's brittleness might be a disadvantage.
The choice between tungsten carbide and diamond often comes down to the specific requirements of the application, including factors like the type of wear expected, the environment in which the material will be used, and cost considerations. Both materials continue to play crucial roles in various industries, from cutting tools and drilling equipment to high-end jewelry.
As materials science continues to advance, we may see the development of new super-hard materials that challenge diamond's position at the top of the hardness scale. However, for now, diamond retains its crown as the hardest known natural substance, with tungsten carbide following closely behind as a versatile and highly valuable material in its own right.
FAQ
1. Can tungsten carbide scratch a diamond?
No, tungsten carbide cannot scratch a diamond. Diamond is harder than tungsten carbide on the Mohs scale (10 vs 8.5-9.5), meaning diamond can scratch tungsten carbide, but not vice versa[2][7].
2. Why is tungsten carbide used instead of diamond in some applications?
Tungsten carbide is often used instead of diamond due to its lower cost, greater toughness, and easier manufacturability. It's particularly useful in applications where extreme hardness is needed, but diamond-level hardness isn't necessary[21][24].
3. Are there any materials harder than diamond?
While diamond is the hardest natural material, some synthetic materials have been created that may be harder. These include wurtzite boron nitride and lonsdaleite (hexagonal diamond), though their practical applications are currently limited[17].
4. How does the cost of tungsten carbide compare to diamond?
Tungsten carbide is generally much less expensive than diamond. This makes it a more cost-effective choice for many industrial applications where extreme hardness is required[21].
5. Can tungsten carbide be used in jewelry like diamonds?
Yes, tungsten carbide is increasingly used in jewelry, particularly in men's wedding bands. It's valued for its durability, scratch resistance, and modern appearance. However, it doesn't have the same brilliance or fire as diamond, so it's not typically used as a gemstone[16].
Citations:
[1] https://www.allied-material.co.jp/en/techinfo/tungsten_carbide/features.html
[2] https://en.wikipedia.org/wiki/Tungsten_carbide
[3] https://www.fa.ihrcarbide.com/news/is-tungsten-carbide-stronger-than-diamond/
[4] https://create.vista.com/photos/tungsten-carbide/
[5] https://www.tungstenringsco.com/blog/2023/06/tungsten-vs-diamond/
[6] https://www.tungstenman.com/tungsten-carbide-hardness.html
[7] https://www.gemsociety.org/article/does-diamond-hardness-matter/
[8] https://www.carbide-part.com/blog/tungsten-carbide-hardness-vs-diamond/
[9] http://www.carbidetechnologies.com/faqs/
[10] https://www.rarecarat.com/blog/diamond-ring-tips/diamond-questions-we-ve-got-answers
[11] https://jewelrydepotusa.com/metal-comparison/
[12] https://www.retopz.com/57-frequently-asked-questions-faqs-about-tungsten-carbide/
[13] https://en.wikipedia.org/wiki/Superhard_material
[14] https://carbideprocessors.com/pages/carbide-parts/tungsten-carbide-properties.html
[15] https://www.carbideprobes.com/wp-content/uploads/2019/07/TungstenCarbideDataSheet.pdf
[16] https://www.menstungstenonline.com/tungsten-diamond-two-hardest-materials-go-hand-in-hand.html
[17] https://www.reddit.com/r/Gemstones/comments/1ahga1f/what_gemstone_other_than_diamond_is_harder_than/
[18] https://en.wikipedia.org/wiki/Diamond_industry
[19] https://www.alamy.com/stock-photo/tungsten-carbide.html
[20] https://www.minerals.net/mineral/diamond.aspx
[21] https://www.burdental.com/blog/comparison-of-dental-diamond-burs-and-tungsten-carbide-burs
[22] https://stock.adobe.com/search?k=tungsten+carbide
[23] https://www.shutterstock.com/search/diamond-hardness
[24] https://triaticinc.com/blog/the-difference-between-diamond-core-bits-carbide/
[25] https://chemistry.stackexchange.com/questions/102971/why-can-a-diamond-be-broken-using-a-hammer-if-its-the-hardest-natural-substance
[26] https://eagle-dental-burs.com/blogs/articles/diamond-vs-carbide
