What is Phosphor Bronze?

Phosphor Bronze Rod

What is Phosphor Bronze? Phosphor Bronze is an alloy of copper with tin and little unit of phosphorous. If we talk in proportion tin is 0.5-11% and the phosphor is around 0.01% to 0.35%. Tin increases the corrosion resistance of alloy and phosphorous increases the wear resistance and the stiffness of the alloy. Other alloys which include are aluminium, iron, lead, manganese, nickel, silicon and zinc. 

Phosphor Bronze is used for springs, bolts, truss wire, blades and various other situations where resistance to fatigue, wear, and chemical corrosion is required. Here are some of the feature of Phosphor Bronze:

· Has a good electrical conductivity

· Good product for strength performance

· Low coefficient of friction

· Excellence Elasticity

Phosphorous helps in reducing the viscosity (the resistance of fluid in the change of shape) of molten alloys which results in easier and cleaner to cast. Phosphor Bronze was invented by George Montefiore - Levi. George Montefiore-Levi was a Belgian politician and industrialist.

Phosphor Bronze is useful for the welding of Copper Tin Bronzes (Cu-Sn-6-8%) and Brass (Cu-Zn). The electrode of Phosphor Bronze is also suitable for joining wrought (made in a specific way) copper-tin bronzes and brasses to cast iron and carbon steel. Phosphor Bronze has applications in Electrical Products such as Connectors & Transistor Terminals, Consumer Electronics, Telecommunication, Automotive, Oil & Gas exploration, some parts of textile machineries, anti-corrosive chemical machinery parts and in many more has phosphor bronze has a wide range of application. Phosphor Bronze use in many industries and in-depth use is mentioned in the below article.

This alloy Phosphor Bronze use in joining of base metals of similar composition. Phosphor Bronze electrode is used in the construction of equipment for the chemical industry and petrochemical industry. The use of this product is high in naval constructions and installations for seawater desalination (desalination is the process of converting seawater into potable drinking water) and other repair works related to naval. Phosphor Bronze electrode can also be used to weld copper if the resistant metal has ample electrical conductivity. An extremely sensitive Phosphor Bronze diaphragm element allows for accurate measurement of low pressure and vacuum in a variety of applications. Ranges are available to measure low pressure and vacuum in inches of water, ounces per square inch, and millimetres of mercury.

 In acoustic guitar strings, Phosphor Bronze is widely used material.  

Phosphor Guitar string was introduced by D'Addario in 1974 and marketed it as an "extended life" strings. In addition to longevity and having greater resilience, these strings resulted in a "warm, bright, and well balanced acoustic tone." Apart from guitar, Phosphor Bronze wires are used in trumpets, trombones, saxophones etc.

Phosphor Bronze is widely used in Fasteners. Some of the Phosphor Bronze Fastener products are Phosphor Bronze Hex Bolts, Phosphor Bronze U Bolts, Phosphor Bronze Hex Nuts, Phosphor Bronze Stud Bolts, Phosphor Bronze Washers and many more.

Phos-Bronze C filler metal is used widely used in surfacing applications. The higher tin (Sn) content (7.0 - 9.0%) gives “PBC” weld deposits higher tensile/yield strength and greater hardness than Phos-Bronze A. “PBC” is used for base metals of similar composition, for joining cast iron to carbon steel for joining brass alloys. Preheating is recommended.

Watch this video (in this video we have used the electrode of Senor makes. Electrode is SME B14 DC. For more information and datasheet of this electrode kindly click on the electrode name) to get tips & tricks for Phosphor Bronze Welding. Phosphor Bronze welding electrode can be used in overlaying on shafts, pumps, bearing surfaces, impellers, pump rotors, building up missing sections and filling cavities in copper alloy castings.

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Check out our article on How to Weld CI and Corrective steps for Porosity.

Porosity in Welding - Causes and Corrective Actions

Porosity is one of the common problems faced by the welders when they weld using the arc welding process, right? Here in this article, we will discuss the various type of causes of porosity and how to avoid porosity during the welding procedure and the best part is we also have in video form, check it out. So, first, let us learn what is porosity?

Porosity is a small hole or pores present in the weld bead. These holes can happen either over or under the weld surface and randomly are of different sizes.

Weld Holes

There are various reasons for the formation of pores on the weld surface. Reasons like:

• Contaminated electrode, consumable, filler wire, work surface, etc.
• Air or kind of draft disturbs the delivery of the shielded gas which results in porosity. Fan 25 feet away also can disrupt the delivery of shielded gas.
• Size of the arc also plays an important role; longer arc increases the chances of porosity.
• Defected gun nozzle, distance of nozzle from welding material, or the wrong angle of the gun can also help in forming the pores. So, always check the nozzles before you start welding.
• Presence of rust, paint, oil, chemicals, etc. releases a large volume of gas. As this decompose gas starts forming, and oxidation starts which leads to moisture and lastly gives us the nice big holes.
• Inappropriate quantity of flux. To avoid this always use the branded electrodes.
• Improper welding procedure and incorrect welding surface treatment.
• Weld surface that contains high Sulphur, Phosphorous or Silicon may result in highly gaseous composition which results in holes during the welding process.

Luckily, porosity is the defect which has 90% prevention rate, let's check out the corrective actions to take to prevent the porosity:

• The electrode or filler wire should be cleaned and made free from oil, grease, chemical, moisture, etc., not only the electrode but the base metal also should be free from moisture, oil, grease or any other toxins.
• Before welding, the oxidation process must be done without any mistakes to remove all the content of oxygen from base metal. The oxidation process will prevent contact with oxygen while the welding process. A proper deoxidant electrode should be used.
• Weld metal should not be exposed in air, which will prevent the metal from contact with oxygen or hydrogen. If the metal gets moisture by someway easy fix is to preheat the surface at the temperature between 94-degree Celcius to 104-degree Celcius.
• To avoid the weld defects the electrode, weld metal, flux or filler wire must be ensured to be free from moisture and in dry condition.
• Proper arc length and flow of current should be maintained.
• Gun nozzle should be checked before the welding procedure, the gap between the nozzle and the welding surface should not be more which results in contact with air and creates the moisture and then the porosity, again the less gap between them will overheat the welding surface.
• A 5- to 15-degree angle which is perpendicular to the joint, is an acceptable angle for forehand or backhand methods with GMAW or FCAW guns and SMAW electrodes.
• Chemical composition of the surface should be predicted prior, so the defect can be avoided. There are so many types of electrodes available in the market for different types of weld surfaces. If you are new to the welding world, take suggestions from the experienced welders or contact us, we are here happy to help. To get more information on every single type of electrode, visit this site.

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 Also, check our another article on How to weld Cast Iron and what is Phosphor Bronze.