Hokotol, which is a brand name for a modified 7050 series alloy, and 7075 are zinc-rich aluminum alloys that are used to manufacture a wide range of products. With that in mind, here is detailed look at both of these alloys.
What is Hokotol?
HOKOTOL was originally developed as a high-strength aluminum alloy for the aircraft industry; this alloy was further developed and optimized to satisfy the most demanding applications of the industry of the mold construction industry. This modified 7050 alloy is characterized by high tensile strength, excellent machinability, low weight, excellent thermal conductivity, uniformed distribution of mechanical properties, excellent electrical conductivity and great dimensional stability. These qualities make Hokotol highly resistant to wear.
Welding Conditions
General
- In comparison to steel the welding temperature is not visible since aluminum melts do not turn the color to red
- High energy (heat input) should be quickly applied
- Oxide film (melting temp.:2020 °C) on the material surface is harmful to welding. It should be removed before welding.
Welding Method
- MIG and TIG are generally used. For thick plates, MIG is the better method to apply.
What is 7075?
7075 was developed in 1943 by secret by Japanese Company for the use of airframe production for the Japanese Navy. This alloy is characterized by high tensile strength matching that of most steel alloys. Some of the alloying elements include zinc, manganese, iron, chromium, magnesium, copper, silicon and titanium elements. It’s is worth noting that this alloy has several different tempers 7075-0, 7075-T6, 7075-T651, 7075-T7 and 7075-RRA. Each of these tempers has unique properties that make them suitable for specific manufacturing scenarios. This alloy come’s in plate form and several shapes, rounds, hex and square bar. Overall, the 7075 product is used to manufacture products and equipment/machinery that require a high strength-to-density ratio. What’s more its lightweight nature makes it suitable for use in manufacturing hang gliders and bicycle frames. It’s widely used to manufacture weapons including US Military’s M16 rifles and Sig Sauer firearms. Manufacturers of lacrosse sticks and tableware also use this alloy.
Advantages of Hokotol over 7075
HOKOTOL offers uniform distribution of mechanical properties across the thickness of the plate aluminum plate. It also offers excellent machinability compared to other products. Due to its great dimensional stability, HOKOTOL can handle stresses related to heat/cold as well as compression and stretching compared to 7075.
Hokotol high yield and tensile strength makes it an ideal material for use in manufacturing scenarios where steel would be too heavy. Since Hokotol is as strong as steel, its lightweight nature alloy does not compromise the quality of products.
High-strength aluminum alloys such as Hokotol are generally difficult to weld. However, repair welding is quite possible with Hokotol when as appropriate welding method such as MIG and TIG are used along with a suitable filler alloy. Over the past few years there has been great strides made in welding of these new aluminum alloys. Another area where improvements have been made is texturing, there are end users using both acid bath and laser etching the Modified 7050 aluminums.
