Soldering iron is vital when it comes to heating metal parts that require joining and melt the solder, which is then introduced as a liquid into space between two metals and fuse them together. This is a vital tool, and its working part usually is the tip.
The heat has been designed to help in maximizing heat conductivity, and it is often angled at 30 to 40 degrees angle. In addition to that, a soldering iron tip features a working edge that is round, which helps in improving its efficiency significantly.
Furthermore, the shape, weight, material, and size of a soldering iron tip tend to have a significant impact on the productivity of your soldering iron. To understand this better, in this article, we shall be discussing; what are soldering iron tips made of and the material used help in improving its functionality.
The Material Used In Creating Soldering Iron Tips
A soldering iron tip is designed from copper. This is highly essential since copper has very high heat conductivity, and it is the most desired characteristic for the soldering iron to work effectively.
However, despite being an excellent material for use in soldering iron, copper tends to decompose or corrode rapidly as it reacts with certain soldering fluxes such as ammonium chloride. It tends to oxidize while idling between soldering operations, and in addition to that, it wears away rapidly due to its mechanical softness.
Nonetheless, this invention tends to contemplate the provision of an improved soldering iron tip that possesses a suitable thermal characteristic for flawless operation.
A material that tends to substantially free from decomposition or disintegration by oxidation along with soldering fluxes and the one with very great mechanical strength that is hard and resistant to wear will be the best. This simply means copper material contemplates an improved tip that is as effective as a copper tip, and it has better longevity than copper.
According to this invention, the working tip of the soldering iron made from an alloy that mainly consists of copper; however, having a small quantity of beryllium and the remaining part should have a useful alloying characteristic of cobalt. Therefore, the most preferred alloy should consist of 97% copper, 2.6% cobalt, and 0.4% beryllium.
However, most of the soldering iron tip consists of a solid copper core, a layer of plated iron, a layered plate of nickel located behind the working surface as well as a plated chrome layer. Usually, copper is used as the core material since it offers good heat transfer.
On the other hand, the nickel-plated layer is a non-wetting layer designed to help keep your solder from wicking away from the working surface of the tip. The absence of the nickel-plated layer will cause the solder to travel preferentially up the soldering iron tip into the heat source. This will make it relatively challenging to apply solder to a soldering joint.
In addition to that, the chrome-plated layer acts as a protective layer. The iron layer, on the other side, is considered the critical working layer, and it affects the longevity of your soldering iron tip significantly.
In most cases, plating failures are as a result of an iron failure. Usually, the iron tends to fail in different ways, depending on the failure mode. Therefore, it is vital to understand the type of failure mode that is occurring so that you can apply the correct action.
Like any other material, iron tends to have its weaknesses as well as strong points. Several soldering iron tip manufacturers have carried out an investigation on several materials that can be sued as an alternative. However, until now, iron remains to have the best property for use in soldering applications.
Why is iron plating vital?
Why has iron been considered the best for use as a solder tip by all the manufacturers across the globe? This is a question worth answering and understanding. The reason as to why iron plating is considered vital includes:
Good heat transfer
The primary task of a soldering iron is the transfer of heat; this means that you need a material that features good heat transfer property. Any solid tip of soldering iron should have a good heat transfer for improved effectiveness. Furthermore, metals are ideal for use as opposed to ceramics. Iron is known for having good heat transfer properties; however, copper is the best.
Does not dissolve in a solder
Usually, lead-free solder is made from a combination of silver, tin, and relatively small amounts of copper. A molten tin solder is known for dissolving rapidly several metals, which includes copper. This means that a soldering iron tip made from copper needs a protective layer that will not dissolve quickly in tin.
One of the few metals that cannot dissolve in tin is iron; this makes it ideal for extending the longevity of a soldering iron tip. However, molybdenum is known for resisting dissolution when exposed to the molten tin, and it is said to have a better mechanical property compared to iron.
Wettable
The reason as to why iron is the best option over molybdenum is because the working surface tip of soldering iron must wet to help in transferring molten solder. In addition to that, it has to help in heat transfer, which is a property that iron possesses.
Good physical as well as chemical properties
These consist of abrasion resistance, ductility, and melting point, among others. Despite iron is not the best in both of these categories, it still features acceptable mechanical properties which makes it the best.
Processable
You can easily apply iron on a copper substrate with excellent adhesion by several techniques. Usually, electroplating is the most common method
Final Thoughts
Copper is the best material when it comes to heat transfer properties; this makes it the best material for use in soldering iron tip. However, since it tends to dissolve quickly in molten tin, which is a common element in solders, the copper tip will need a protective layer to help protect it from melting while soldering. Iron is the best material used to protect copper since it does not melt when exposed to the molten tin.
