Just as ferrous metals, heat treatment of non ferrous metals can be performed in two ways which include: solution heat treating and annealing. In my previous article, I have explained the process of heat treatment of ferrous metals.
Heat treatment of non ferrous metals.
Solution heat treating:
It is carryout to increase the tensile strength of nonferrous alloys changing them into a solid solution and controlling the rate of returning to a change structure of their mechanical mixture. In this heat treating the alloys are heated to a specific temperature below the melting point of the materials, it is then quenched or rapidly cooled. The solid solution obtained during the heating process remains stable due to the cooling process. At this point, aging and precipitation hardening (process that helps the materials in alloy to change or precipitate out of the solid solution.) will be done to ensure the alloy do not change to its original configuration after some time. Aging gives the resultant grain structure in the metal a greater tensile strength than its original condition. Base on the alloy type, artificial aging process can also consist of simply aging the alloy at room temperature for specific time and then cooled with air.
annealing of nonferrous metals can be achieved as far as nonferrous metals are heat-treatable. Annealing is done to relieve the hardness of cold working. Just as it is being done in ferrous metals, by subjecting the alloys to heat at a specific temperature and then allowing it to cool slowly to room temperature. the slow cooling allows full precipitation of the constituents and produces a refined microstructure. Whilst rapid cooling will cause nonferrous alloys to become softer than normal state.
Let me use this opportunity to explain some terms you need to know to get enough of this course
Quenching – this is the process of cooling metal at rapid rate by immersing it into oil or water.
Precipitation hardening – it is also known as age hardening or aging. It is accomplished if certain metals are held at elevated temperature without quenching. Precipitation hardening helps to increase the yield strength of malleable materials.
When a precipitation hardening metals are quenched, its alloying elements trapped in solution which causes a soft metal and when solutionized metal undergoes aging, it allows the alloying elements to diffuse through the mere structure and from intermetallic particles. These intermetallic particles will form into nucleus and fall out of solution helping increase the strength of the alloy.
- Heat Treatment of Aluminum and Aluminum alloys
- What is Heat treatment of metals? – its advantages and disadvantages
Nitriding – nitriding is another way hardening an alloy. It is carried out by adding nitrogen to a metal surface through content with ammonia gas. These process produces case hardening if it’s not quenched.
Decarburization – this is done to remove carbon from the surface of steel, either by subjecting the metal to heat or by aging process of oxidation.
Cold working – this process is not a heat-treating process, but it is used to change the characteristics of metals. It is performed by deforming metals at room temperature without fractioning. Cold working gives more tensile strength and better machinability to the metal. However, it changes its shape.
And that is it for this article, heat treatment of ferrous metals. Answer the question below via my comment box to assure me you understand. Ask questions and please share. Thank for reading!
Question: In your own understanding explain any of two process of heat treating non ferrous metals