In the search for an appropriate construction material, two metal alloys – Brass and Bronze should be considered. These famous alloys of copper have been in exixtence for several decades, and still finds extensive use in our world today.
The longevity in the use of these two great metals have been as a result of the unique properties they possess. These properties also afford them their widespread applications.
As alloys of copper, brass and bronze have certain similarities. These simililarities allows for their similar applications. However, brass and bronze vary also to an extent.
They differ in composition and this allows for the different properties they have.
Selection of the right alloy to use, is an important step in the creation of any of your projects, as the ideal material will be able to cater for all the needs of your project.
Reading through this article will help you make informed decisions on which alloy to use for your projects, as a detailed comparison is provided.
What is Brass?
Copper and zinc make-up this alloy. It contains about 67% copper and 33% zinc. These percentages can vary, resulting in brass of different grades and properties.
Other forms of brass exist. These forms are as a result of the addition of other elements to brass. These elements give brass a unique property.
Manganese, aluminum, silcon etc. are examples of elements that can be added to brass. Brass, for example has an increased strength when the proportion of zinc in the mixture is increased.
Properties of the Brass Alloy
The reasons for the widespread use of brass are its properties. Here, these properties will be looked at. They include:
Malleability
Brass is a very malleable metal. Certain properties attribute to this. One is the flow property of brass, another is the low melting point of brass when likened copper and its other alloys.
Brass is more malleable than bronze and copper.
Non-ferromagnetic
When placed beside a magnet, brass gives no response. It is neither attracted or repelled b the magnet. This is because brass contains no iron. This makes recycling brass easy, as it can be melted and recast to the suitable form with relative ease.
Corrosion Resistant
As brass doesn’t contain iron, it doesn’t undergo rusting. Certain forms of brass can withstand the strong corrosive effects of salt water, making brass useful in constructing the outer covering of ships.
This anti-corrosion property of brass is increased when aluminum is present, as a tough layer of aluminum oxide is formed.
Bactericidal Activity
Brass belongs to the class of non-ferrous metals that can kill bacteria which they come in contact with. These metals use their metal ions to react with some proteins in the bacteria, causing its death.
High Frequency to Fracture Ratio
Brass has a high frequency-to-fracture ratio under immense stress. This is a result of brass being stronger and more compact than pure copper, making cracks occur when much stress is applied
Advantages of Brass
the following are the advantages of brass, affording its various applications. They are
- It can be used for long periods i.e. durable
- Beautiful appearance. With a gold-like color, brass has decorative uses.
- Bactericidal property
- Low friction coefficient. This allows its use in movable parts of machines.
- Malleability
Application of Brass
Now to the uses of brass. They include:
Musical Instrument
The use of brass in musical instruments is a result of its good malleable and feasible properties and its good ability to withstand corrosion.
Silver and gold are ideal for use, but brass is a cost-effective alternative. The tuba, trumpet,clarinet etc. are some of the nusical instrumets which brass is used in their making.
Plumbing
Brass is useful in the construction of plumbing pipes. One property of brass, is it good resistance to corrosion.
It helps eliminate the need for constant need to replace pipes and also contamination of the water supply due to corrosion, as seen with ferrous metals.
Decorative Purposes
Due to the color of brass, it is used for a variety of purposes to improve the appearance or aesthetics of products. Whistles, coins and some statues are made using brass.
Machine Application
Brass is ideally used in machines where a small amount of friction is to be overcome. Examples include door knobs, locks, bearings, etc.
What is Bronze?
Bronze is a reddish brown alloy of copper. The mixture of tin and copper makes this alloy. Differences in the amounts of the individual forming elements leads to different grades of bronze.
In preparing bronze, typically about 88% of copper is used, and the remaning 12% percent being tin. Other elements can also be added, in order to prepare a bronze alloy with improved qualities over its parent elements.
The use of varying amounts of silicon, lead, aluminum and some other elements have shown to impact on the properties of the bronze formed.
The existence of bronze has been far back as the Bronze Age (about 3000 BC), and it remains in use to date.
Characteristics of Bronze
Some of the important features are outlined below.
- Bronze is a can be drawn into wires effectively
- It forms an oxide of copper when exposed to air, and this further allows protection of the metal from corrosion.
- It is harder than pure copper but brittle.
- It possesses a low friction coefficient with other metals.
- It also doesn’t produce sparks when stuck against hard surfaces, as compared to steel. This makes it useful in environments where flammable materials are worked upon.
- Allows the passage of heat and electricity readily, compared to steel.
- Possession of reddish brown color
Advantages of Bronze
Bronze has the following advantages, which promote its usage. These advantages are as follows:
- It is cheap compared to steel and other metals
- High resistance to corrosion
- It is very strong and lasts long
- Doesn’t tarnish easily
- Easy to use
- Very good electrical and heat conductivity
Uses of bronze and its Alloys
Based on its properties and its ability to be formulated into different grades, bronze has found numerous applications in the industrial world. These uses include:
Use in Saltwater Environments
Bronze is commonly used in these enviroments, as it is not fazed by the corrosion caused by saltwater. Its resistance to these coditions allows for its use in the construction of some ship parts.
Sculpture and Statue-Making
Once use of bronze since time past and present, is in creating sculptures or statues. Its dull and slightly gold color helps in its use for this course.
Bearings and Fittings
As a result of the low coefficient of friction against other metals bronze has, it is used in manufacturing small electrical motors’ bearings.
Use in a Flammable Environment
Another useful property of bronze, is abiliy to not ignite when a large force is applied on it.
So, it is used in making hammers, wrenches, and other materials used in those environments.
Musical Instruments
It is used in making bells (when containing tin) and cymbals. Some certain instruments are also coated with bronze.
Coins
It is mostly used in coins and also medals, as a result of its appearance and hardness
A Distinct Look into the Differences Between Brass and Bronze
Now comes the main part. It’s time to see how well Brass and bronze differ from the other.This will help guide your decision-making process on which alloy to use for your projects.
The comparisons will be based on certain features, such as; appearance, alloys available, cost, conductivity, and many more. Let’s begin!
1. Available Alloys
Brass alloys
These alloys are formed either by the presence of other elements other than copper and zinc, or by varying the proportion of each individual element. They are:
- Cartridge Brass – this alloy has the ability to form under al low temperature. This property allows for its use in automobiles, hardware, and ammunition.
- Yellow brass – also called Alloy 272. This alloy typically contains 33% zinc and has widespread industrial uses.
- Alloy 330 – also called C33000. This alloy contains lead in small amounts and is of good application in situations where high machinability is required. It is used in the production of pipes due to its cold-working feature.
- Clock brass – also called Alloy 353. This alloy is used in clocks and wristwatches because of its ability to create precise constituent parts due to its remarkable machinability.
- Free-machining Brass – also called alloy 360 or C360. This form of alloy contains 3% lead, and this imparts improved malleability to the brass formed. As a result of the malleable property, C360 possesses excellent machinability and versatility.
It has use in producing hardware and other materials.
- Naval Brass – also called Alloy 485. This brass alloy contains small amounts of tin in addition to copper and brass. There is a tin-induced improved resistance to corrosion effect on this type of brass, making it useful in saltwater environments.
Bronze Alloys
These alloys occur as a result of what is contained in the bronze during manufacture. The popular alloys are:
- Alloy 932 – this is a form of tin bronze with a high lead content. It is used in the manufacture of non-pressure parts and washers.
- Alloy 954 – also called C95400. This alloy resists the wearing and change of its shape under the pressure of immense loads. It is used to manufacture liners, plungers, industrial bearings, and so on.
2. Differences in The Physical and Material Properties of Brass and Bronze
One form of distinguishing between these two alloys, is their physical and material property. They include:
Elemental Composition
This talks about what the alloys contain. Clearly stated, brass is made-up of zinc and copper, while bronze, is made-up of tin and copper.
Both alloys can contain other elements which impacts on their various properties.
Also, the proportion of the elements differ, bronze usually has a higher copper content than brass.
Ability to withstand corrosion
In comparison, bronze has a better resistance to corrosion than brass.
In bronze, an unreactive oxide layer of copper is formed when the metal is exposed to air. This makes the alloy able to withstand the corrosive ability of seawater.
Brass having a lesser amount of copper as compared to bronze, has a fair resistance to corrosion.
Durability
Brass is a durable metal alloy. Its strength and ability to resist corrosion, are reasons why it can be used for long periods. However, brass cracks under considerable stress, and this can limit its use in areas where high pressures are applied.
Bronze is highly durable. Its strength, remarkable ability to resist corrosion, and toughness impact its durability. The durability of bronze supercedes that of brass.
Weight
The use of density values is one way of differentiating between brass and bronze, in terms of size. Brass is lighter than bronze as it has a density of 8720 kilograms per cubic centimeter, compared to that bronze which is about 8900 kilograms per cubic centimeter.
Machinability
This refers to how easily the material can be machined. Brass has good machinability. Its malleable nature allows for this good property. Bronze also possesses fair machinability. It is a very strong alloy and not very flexible. It is difficult to bend, cut, and mill.
In selecting between the two alloys for your work, brass is preferred for its superior machinability.
Weldability
Brass is welded easily except for the alloys that contain lead. Also, a reduction in the amount of zinc used improves the ability to be welded. Bronze also can be welded. The alloys without lead have a fair amount of weldability.
Both brass and bronze can be welded. The difference is in the techniques used. The Metal Inert Gas (MIG) or Tungsten Inert Gas (TIG) techniques are usual for brass welding.
At the same time, bronze-shielded metal arc welding (SMAW) is the most used welding technique.
3. Differences Between Brass and Bronze in Their Ability to Conduct Heat and Electricity
These are also important points to consider in your selection of the appropriate alloy for your work.
Electrical Conductivity
In terms of electrical conductance, brass has a slight edge over bronze. Both metals are quite poor in conducting electricity.
Thermal Conductivity
Brass has a higher thermal conductivity than bronze. With conductivity values of 64 British Thermal Unit (BTU) per hour per feet squate per degree Fahrenheit, for brass and 15 British Thermal Unit (BTU) per hour per feet squate per degree Fahrenheit for bronze.
4. Strength: Brass vs Bronze
An important question to be answered is “will the material be strong enough for my project?”. Knowledge of the strength differences will help you conclude.
Tensile Strength
Bronze has superior tensile strength compared to that of brass. This is evident in the values obtained when their tensile strengths were measured.
Bronze’s strength occurs within a range of 350 – about 635mPa, with brass is with a strength of 338 to about 470mPa.
Yield Strength
Bronze comes tops again in this aspect. The calculated yield strengths shows this superiority. Bronze having values with peaks at about 800mpa, while brass is at 124mpa.
5. Producibility
In designing your products, you must choose the right materials that will create the right product of the desired quality. The ability of your material in making the products has to be assessed.
Formability
The formability of brass is low, with it not being amenable to stress, fracturing under a lot of pressure.Bronze generally has low formability except for its phosphor alloy, which has good formability and can undergo cold forming to the desired form.
Melting Point
To form adequately, a reduced temperature is required for the alloy to melt and be utilized. Bronze has a higher melting point than Brass, thereby requiring a greater amount of temperature or heat to form.
6. Appearance and Touch
There are unique properties that they both have, and this aid in their differentiation.
Color
This is one distinguishing factor. Bronze has brick red color with a gold tint while brass has a dull golden yellow color.
Hardness
Bronze is usually harder than brass. This is evident using several hardness tests, such as the brinell hardness test, Vickers hardness test, and the likes, with bronze having greater values.
7. Pricing and Options
When, it comes to cost, brass is cheaper. One reason for this is due, to the copper content in brass as compared to bronze.
A higher copper content equates to a higher cost as copper is relatively expensive to procure.
Also, the processes involved in bronze’s manufacture add to its overall cost. Zinc is usually cheaper compared to copper. So, its presence in brass offers little to its cost.
Benefits of Brass and Bronze
The use of these metals has improved over time, and so has the demand. This has been a result of the benefits of using these alloys.
Some of the benefits of brass include:
- Durability
- Bactericidal activity
- Good aesthetics
- Malleability
- Low friction coefficient.
The use of bronze is as a result of
- Ability to withstand corrosion
- It is strong and durable
- Ease of handling
- Appreciable thermal and electric conductance
Brass vs. Bronze: Which to Use
The differences between these two metals offer you a guide as to which is ideal for your work.
Certain principles also guide your choice, they include:
Cost
This is one critical aspect to be considered. Brass is usually the cheaper option when the cost is a concern.
Application
What kind of project you intend to do determines the most suitable choice of metal. Bronze is highly corrosion resistant and is suitable in seawater environments, while brass has antibacterial properties and is useful in water purification and filter bedding.
Ease of Operation and Handling
This involves how easy it will be for you to carry out your work seamlessly with the alloy. The machinability and operation come into question. Achieving this will give you the best to use in your work.
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