High-pressure fluids do wonders when it comes to machining. In fact, you don’t need some ultra-expensive specialized fluids for that purpose – you only need water or maybe mineral oil.
Perhaps using a liquid to shape metals sounds ludicrous, but it turns into a powerful force once you use it in the right environment. Manufacturers love this approach for its cost-effectiveness and practicality.
And the process goes by the self-explanatory name of hydroforming. It operates with tubular parts and sheet-metal parts to create some really complex and sturdy components from ductile metals, ensuring minimal material waste.
Hydroforming is better at reducing tolerances than stamping and other traditional methods, making the final product strong and durable. Let’s dive in and see what this method is all about. Click here to find out more information.
The setup needed for a hydroforming operation is simpler than you would expect.
Basically, it combines a hydraulic press and a die with water systems, allowing the high-pressure fluid to transform the metal workpiece, forcing it to adapt to the die. Hydroforming uses fluid pressure to achieve the desired effect, whereas other fabrication methods use a punch.
Once the chamber is filled with hydraulic fluid, it applies great pressure on the workpiece, which starts taking the shape of the mold. Once you get the object you wanted, you simply remove the new piece from the chamber and wash it. Usually, it requires a little more work with a laser or some other tool for the ultimate finish.
Several different elements come into play here. Picking the right raw materials is very important: not many metals can be shaped with hydroforming, so it’s best to investigate that area thoroughly before investing in the equipment.
Also, the temperature is a significant factor when determining the forming force. For example, the workpiece would be less malleable at room temperature, so naturally, you would use greater force.
Which Material Is Right?
The success of hydroforming will depend largely on the used material. Some metals have better mechanical properties than others, and they will get priority.
As a general rule, all cold-forming processes can shape the same metals, including hydroforming.
If you have any experience with bending, drawing, shearing, or squeezing, you’ll have a good idea of what to use. This group includes aluminum, regular and stainless steel, lead, cobalt, bronze, and others.
For this technique to work, metals need to have high ductility (the ability to deform without breaking.) Furthermore, they must have a fine grain structure, uniform elongation, difference between yield and tensile strength, and so on.
All these factors are equally important: if one property is missing, there will be faults, and you won’t achieve the desired geometry.
Experience is paramount here: operators who have handled metals for many years can tell you exactly how a particular metal will behave in a given situation.
Tubes and Sheets
As a metal fabrication process, hydroforming deals with blanks in the form of tubes and sheets. There are subcategories, of course, but these are the main two.
Both are used to produce many different components, and we’ll need to see the specific requirements for each category so you can understand them better.
Tubular hydroforming has been around for about fifty years and has improved considerably since its modest beginnings. Operators used it to transform low alloy stainless steel, aluminum, brass, and other pliable metals.
, it enlarges a tube against a die cavity by applying internal pressure, which, combined with counter-pressure and axial feeding, creates a force to be reckoned with. Tube hydroforming has entered mass production in recent years thanks to technological developments.
There are several reasons why this type of hydroforming is now highly popular with manufacturers. It uses fewer parts, which in turn reduces production costs significantly.
Then, you get a lighter finished product resulting from optimal wall thickness and design, and weight is highly significant in metallurgy. You can have a beautifully shaped component, but if it weighs more than it should, you will have problems transporting it and integrating it into a structure.
The second category is known as sheet hydroforming, which uses thin metal sheets instead of tubes. Here, you place the sheet on the hydroforming press.
pretty much the same approach: you apply pressure on the sheet, so it conforms to the die underneath. In this way, you can get a vast range of components applicable in different contexts.
And not just any industry: those that require complex, specialized parts, such as medical, healthcare, power generation industries, aerospace, etc.
Hydroforming is generally more effective than stamped parts in terms of product strength and weight. The objects you get with hydroforming are sturdier, more durable, and lighter than stamped components.
For this reason, the automotive industry uses hydroformed parts in their constructions, reducing potential damage during traffic accidents.
There are many other advantages to be gained with hydroforming. For instance, some assembly and welding procedures could become unnecessary, as hydroforming does all the work for them.
Then, you could repurpose several different parts as a single component. This comes in handy when you have leftovers from past projects; instead of throwing them away, you reassign them to a new role.
In the aerospace industry, the services of a hydroforming company and manufacturer are very much welcomed. We’re talking about highly complex components that need to be produced as professionally as possible.
Besides being economical, sheet hydroforming is the best solution for irregular and asymmetrical designs. It’s also way faster than die stamping and in a fast-paced industry such as aerospace, time is money.
You might remember the MythBusters episode from a decade ago, where they used sheet metal to create floating devices for a paddle-wheeler. They showed TV audiences how powerful the process truly is, but industries know this very well.
And considering all the benefits like simple tool installation, cost savings, precision and accuracy, and material versatility, hydroforming won’t become obsolete any time soon.