The difficulty of processing of titanium alloys, such as cutting and forging is a well-known fact.
It is hard so it needs to be cut taking time, but there are are many cases of ignition from its shavings, and due to the hardness of the material it causes chatter from the mismatch of the tools. In many ways, titanium is metal hard to conquer.
Even then, it was the fabrication of the Hex groove that annoyed us the most.
At the beginning of the business, we were manufacturing Hex grooves using a different cutting from now. The tool was only shallowly engaged, so we thought about inserting tools to a deeper position, and collaborating with a metal tooling equipment manufacturer, it became a big task for us for nearly 2 years.
Also, nearly every day we are getting inquiries from overseas manufacturers."Let us make your products", "We have excellent facilities". They are marketing there products manufacturing contracts and sales of machines. So we sent a simple drawing to several companies and had them manufacture samples for us. This is shown in the next picture.
Although the depth to insert the tool can be secured, as you can see in the image, the size of the hole at the bottom is conspicuous. After examining their manufacturing process, it turned out that they were processed by the "cold press" manufacturing method. In other words, it is a processing method where the bottom hole is created to reduce the area to be pressed and reduce the resistance in order to accommodate the lack of pressure of the press (pressing strength). However, before we consider the lack of the inadequacy of machine, from the theory of forging titanium alloy, we know that it takes raising the temperatures to a narrow range between 700°-900°C(1300°-1650°F). For lower temperatures cracks can form, and for higher temperatures, it can turn to "ashes" due to change of composition. Needless to say, it could not be adopted as a product.
Currently, our products use high-frequency induction heating machine to accurately perform temperature control even in narrow temperature ranges and we succeeded in forging them using a 60-ton press. In addition, technical progress of forging the shaft part has also improved. For example, the maximum outer diameter of Our Be Zero M14 lug bolt is 27 mm and the minimum outer diameter of 14 mm, but the base shaft is expanded from 14mm to 27mm by forging. Of course, if in an ordinary manufacturing method (non-forged), cutting is done from 27 mm and it is scraped down to 14 mm.
Although it is a digression, we are making Inconel screws to be used for artificial satellites on the same production line.