Essential Metals Properties: Can I Machine This Material?Matt Kerster
The aerospace industry has seen a significant influx of composite and other materials; used in various aspects of aircraft construction, fabrication, and for internal components. Since the 1920s, metals have been the mainstay of aircraft construction and continues to be the primary materials used today.
The most common aerospace materials include aluminum, stainless steel, titanium and various copper and brass alloys. These metals are typically used, due to their strength and resistance to corrosion, and their ability to maintain integrity in temperature extremes.
There are many different properties that are required for aerospace. These include tensile strength, density, malleability and ductility, elasticity and brittleness, and hardness and toughness. In addition to these, and other considerations, aerospace metals often need to be machined.
A common question when making or fabricating a part, for example, is whether the material being used can be machined.
Not All Metal is Created Equal: Considerations for Machining
In the aerospace industry, the two metals that find the most usage are titanium and aluminum. This is due to their high strength, especially with titanium, and the light weight with aluminum.
When it comes to machining, aluminum is a far easier material to work with. Titanium alloys tend to be the most difficult.
According to one industry source,
“Machinability of a material can be defined as the ease with which it can be machined. Machinability depends on the physical properties and the cutting conditions of the material.”
“Pure titanium” alloys are the easiest titanium-based materials to machine. They are not, actually “pure”, but composed of 99.5 percent to 99.8 percent titanium and small amounts of iron and carbon. These alloys are classified as grades 1 through 4, based on the titanium content.
When working with aluminum alloys, machinability is usually a given. Some alloys, however, present themselves as easier materials to machine than others.
The most common alloys used in the aerospace industry are Aluminum 7075 and Aluminum 6061-T6. Of the two, 6061 is one of the most popular aluminum alloy in the industry. Aluminum 6061-T6 is versatile and easy to machine; material that can also be subjected to different heat treatments.
Aluminum 7075 is one of the most common aerospace aluminum alloys, used for highly stressed structural applications. Suitable for machining, 7075 is an important material for making structural aircraft parts, components, tooling, and more. Like its alloy counterpart, 6061, it is heat-treatable, ductile, and exhibits great strength and toughness; strong, and tough.
Titanium, Aluminum, and Steel
The most “machinable” metal materials commonly used in aerospace applications, include most of the aerospace grade aluminum alloys.
Stainless steel is often a better choice than either carbon steel or aluminum; it is not known for being “easy” to machine. It is however, corrosion-proof and can handle high temperatures. This has many uses in aerospace applications.
For example, NASA and other space industries commonly use stainless steel for making rocket and space shuttle parts.
As one source notes,
“Stainless steel alloys have found increasing usage in aircraft components that require great strength but can handle the increased weight. The high corrosion and temperature resistances found in stainless steel make it suitable for a range of aerospace parts, including actuators, fasteners, and landing gear components.”
One of the advantages of stainless steel, offsetting being more difficult to machine, is that it can be machined as thinner material, due to its high strength-to-weight ratio. Its flexibility means that it can be welded, formed, cut, and machined as easily as most carbon steel materials.
Stainless steel is often a preferred metal for industrial machining applications. It requires a low level of maintenance.
Working with AAA Air Support
AAA Air Support has been the premier manufacturer of roll formed products and aircraft roll formed stringers for over two decades. We know aerospace manufacturing and what it takes to excel. We offer the agility, flexibility, and intuitive responsiveness required to meet our customers’ specific needs and concerns.
Our in-house tooling design and manufacturing can supply materials to print at an affordable price. Also, our extensive range of existing inventory provides immediate availability. We offer delivery of a variety of customer part numbers and alloys as next-day shipments. The team at AAA Manufacturing can produce as little as 12 feet of material, if needed, and custom shapes are welcomed.
AAA Air Support provides world-class customer service along with a significant roll forming benefits that include:
- Custom Roll Forming
- Short Runs
- Tight Tolerances
- In-house Tooling Design and Manufacture
In addition, AAA Air Support provide several other value added services; all available upon request.
When you need 100 feet of an aluminum extrusion product, or just a few feet of stainless-steel tubing, AAA Air Support promises that we will always ship out your orders quickly, efficiently, and in accordance with our “Quality Aerospace Standards.”
Our goal for any AOG job is to provide your company with the materials needed to complete the project and efficiently return the airplane back into ‘air service’. Simply put, your requests are always our top priority.
We invite to experience our ‘impeccable customer service’ and become another ‘highly satisfied customer’.
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