How Strong Is Silver Solder ? Comparison With Brazing & Welding

For joining metals, there are three widespread methods: welding, soldering, and brazing. Among them, welding offers the ultimate tensile strength, but this technique can only be applied for the permanent joining of similar metals. On the other hand, soldering assigns the weakest tensile strength for metal joints unless you’re using silver solder. The silver soldering technique is identical to brazing and also offers welding-like tensile strength. Do you want to know How Strong Is Silver Solder? Its joints have the same strength as brazing fillers, and they can sometimes even outperform welded joints

The customary silver solder strength ranges from 40000 to 70000 pounds per sq inch (psi). You can lower the silver solder melt point by adding it to copper brazing alloy. It also results in increased fluidity which enables the molten metal to fill gaps perfectly to create seamless and locked joints.

In addition to incredible tensile strength, there are many more benefits of using silver solder for metal joining. Proceed reading to discover about various metal joining procedures, what properties silver will add to the alloy, how some techniques are comparable, and how they’re distinct.

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Let’s compare different joining procedures

Before going deep into learning various properties of silver solder, it is good to see the key differences between various joining procedures. Understanding the basic similarities and disparities will benefit you to know why Silver offers such soldering power.

From the above table, you can see that soldering, silver soldering, and brazing are identical procedures, but the only difference you found is the melting temperature of filler metal. The filler metal used in soldering is usually weaker than the metals it combines, which causes the joint to collapse. But in brazing and silver soldering, the filler metal is equal to or more potent than base metals.

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Soldering Silver Vs. Soldering

Soldering is a technique of joining two unlike metals using filler metal. Keep in mind that the melting point of these filler metals is typically less than 840° Fahrenheit. Soft soldering alloy has 42% bismuth, 37% lead, 11% tin, 10% cadmium, and merely 4-5% silver. A lower volume of Silver shows its incapacity to form powerful joints.

On the other hand, the melting temperature of silver solders is around 1150 to 1600° Fahrenheit which is way higher than soft solders. Due to this reason,  we prefer silver soldering for mechanical works. A typical silver soldering alloy contains 37 to 44% silver in the whole composition, which is much higher than silver content in soft soldering alloy.

Silver Soldering Vs. Brazing

People usually mix brazing and silver soldering because of the great extent of similarity in both techniques. If you also have the same kind of misconception, then we have identified two key dissimilarities between brazing and silver soldering, which are:

• Silver welded joints demand overlap of metal for stronger bonding which is not the case with brazing
• Silver soldering alloys have higher fluidity than brazing fillers

The fillers used in brazing are typically made up of copper metal, but these fillers can also be alloys with high nickel content. Besides, the other metals found in these alloys are zinc, tin, silicon, phosphorous, and Silver. The silver solders are mostly brazing fillers but with a higher proportion of Silver in the overall composition.

Brazing and Soldering Vs. Welding

Soldering and brazing are two almost identical methods of joining two or more metals by applying melted metal filler as glue. The filler has a lower melting point than the base metal, and heat is given to melt the filler, and then liquid alloy gets pulled by microscopic holes in the base metal. After cooling down, the filler metal acts as a joint between the base metals. Note that these joints are not permanent as they can be melted again.

On the other hand, welding is an entirely different procedure. It doesn’t require a filler metal to be melted to make a joint between two base metals. We can join two or more metals by melting base metals altogether at the joint. You may be wondering why welding applies to only similar melting point metals. If two metals have different melting points, then during the process, one will melt earlier, which creates a mess.

The joint created by welding is permanent, unlike brazing and soldering; in case if you want to separate the two pieces, then you have to cut it. The durability of a joint welded not depends solely on the endurance of the base metal but also on the volume of the metal from the electrode that fills the joint and the weld being manipulated. Moreover, the weld should be as arduous as the base metals are, but usually, it isn’t like that.

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Few amazing benefits of brazing over welding are:

• It does not require expertise to do the procedure
• Joints are correctly filled and smooth as compared to welded joints
• It allows you to join, unlike metals
• It doesn’t change the physical properties of metals by being melted

Advantages of using Silver:

Silver is regarded as a precious metal, just like platinum and gold; that’s why it is not cost-effective. You may also have a question, like most people, why we use it for joining pipes and other metals? Augmenting Silver in any metal changes its properties dramatically, and that is why the resulting product gives consumers the best value for money. Here are some advantages of using silver solder:

Silver reduces the melting temperature of copper alloys

The most widely used silver solder melting points are 1328° Fahrenheit at 33 percent silver volume, 1247° Fahrenheit at 40 percent silver content, and 1202° Fahrenheit at 55 percent silver proportion. Due to the different melting points of various silver solders, it allows you to strengthen the already present joint by putting in another layer of silver solder without demolishing the previous work.

Phosphorus is another metal used for decreasing the melting point of alloys but more sharply than Silver does. Only 1 percent of phosphorus content in any alloy can reduce its melting point up to 120° Fahrenheit. On the other hand, we can reduce just 15° Fahrenheit by adding 1 percent silver. It indicates that using Silver in contrast to phosphorus allows more control over lowering the melting point.

Silver tends to enhance the melting range of alloys

By now, you understand that when Silver is mixed with other metals, it lowers the melting point of these metals. In addition to that, it also can widen the melting point range of the alloys in which it is employed. Because when we heat up the pure metal, it suddenly changes its state of matter from solid to liquid when it attains its melting point. In contrast, an alloy of any metal with Silver melts slowly, which is terrific as a wide melting range is ideal for filling a large gap in a joint.

Silver enhances the ductility of alloys

Many people think that phosphorus is better than Silver when it comes to enhancing the ductility of alloys, but why is Silver so popular? The simple answer is that both metals are very soft in nature; therefore, when mixed with any rigid and tough metal, they boost up its elasticity.

But the dilemma with phosphorus is it bestows ductility to an alloy, but also shapely reduces its melting point, which is not favorable at any cost. That’s the reason we utilize Silver in creating ductile alloys without scarifying the melting point.

How conductive are silver solders?

It is a known fact that pure Silver is the brilliant conductor of electricity due to its low resistance. Only copper is somehow near to the excellent electrical conductivity of Silver but much cheaper and less prone to tarnish. Due to the high content of Silver in silver solder, silver soldering is beneficial in electronics as it creates strong joints between metals and also provides excellent connectivity.

Conclusion:

After reading this article, you now know how strong is silver solder. The silver solder provides the same strength as brazing fillers, and its joints sometimes are equal or even stronger than welded joints. In addition to strength, silver solders have a wide melting range, offer incredible flexibility with high conductivity. Therefore, silver soldering techniques are equally fruitful in mechanical and electrical applications.

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