Ever wonder how you can test the hardness of aluminum?
The benefit of aluminum is often found in its use in different industries like construction, automotive, and manufacturing. However, its strength and ability to support loads without deformation are often critical when designing and manufacturing aluminum-based components. Hence, technicians and engineers conduct hardness tests to confirm its tensile strength. But how do they carry out this test? If you want to find out then, keep reading.
I. What is the Hardness of Aluminum?
The hardness of Aluminum is its ability to withstand a load or force without deformation, abrasion, or disintegration under the impact of the load or force. This hardness is often an essential criterion for selecting an aluminum material in the manufacture or production of components of other products. Aluminum is often considered to have substantial hardness to maintain its structure when impacted by force. This characteristic, coupled with its lightweight, makes it suitable as a production material in several industries like manufacturing and construction.
II. Is Brass Harder than Aluminum?
Comparing Aluminum and brass on a popular hardness scale like the Brinell hardness scale shows that Aluminum has a hardness value of 15 while brass which is an alloy of copper and zinc, has a hardness value of 60. You can conclude, therefore, that brass is harder than Aluminum. However, tempered Aluminum has a hardness scale of 75, making it harder than soft brass.
III. How do you Test the Hardness of Aluminum?
The usual practice for testing Aluminum is using one of the hardness testing methods common to most testing professionals in the industry. These hardness testing methods include Brinell, Rockwell, and Vickers hardness tests. The main activity in these tests is using an indenter with a known weight to cause an impact that produces an indentation on the surface of the aluminum material. After removing the loads, the measurement of the depression helps calculate the aluminum material’s hardness value.
IV. Hardness Test Methods for Aluminum Hardness
Here are some of the most common hardness tests used in the industry to ascertain the hardness of Aluminum.
This test uses an indenter with huge loads making it suitable for very thick, large, and rough-grained material surfaces. The indenter is a carbide ball with a diameter ranging between 1 – 10mm, and its load can be as high as 3,000kgf. The indenter impression made on impacting the material surface requires an optical tool for accurate measurement. The indentation measurement helps to calculate the hardness value of the aluminum material accurately.
For this test, the indenter on the Rockwell hardness testing machine is a tungsten carbide ball of four different sizes or a diamond indenter. During the test, the indenters with a set of known loads cause an impression on the material surface by applying an initial small load followed by a greater final load to drive the main impression. The measurement showing the depth between the initial and the final indentation helps calculate the Rockwell hardness value of the aluminum hardness material. You can combine these indenters with a range of loads from between 15kgf to 150kgf, giving a total of 30 different Rockwell hardness scales.
This hardness test comes with an indenter with a pyramid shape and a load range of 10gf to 100kgf, which is why it applies to a wide range of micro and macro hardness tests. After the impact of the indenter on the material surface, the measurement of the impression’s width helps calculate the material’s hardness value. This measurement often requires an optical device to measure the indentation accurately.
Conclusion
In conclusion, Aluminum has lightweight and anti-corrosion properties, making it suitable for producing various components in different industries. Usually, these industries require carrying out hardness tests to ascertain the strength and suitability of the aluminum material. Hardened Aluminum can be tough and suitable for many industrial productions where its other properties and hardness are critical requirements.