While there are indeed knives made from strong and durable metals, no knife can last forever without any need for sharpening. All materials, including titanium and other strong metals, will eventually dull with use and require maintenance to maintain their cutting edge.
Titanium is a lightweight and robust metal with excellent corrosion resistance, making it suitable for certain applications, such as aerospace and medical equipment. However, titanium is not an ideal material for creating sharp cutting edges. It is challenging to sharpen titanium to a fine edge, and even if it were possible, the edge would not hold up well during use.
Some other high-performance knife materials include various types of steel, such as high-carbon stainless steel, VG-10, and Damascus steel. These steels can be extremely durable and can hold an edge for a long time, especially when properly cared for and regularly sharpened. However, they still require periodic sharpening to maintain their cutting performance.
The truth is that no matter how strong or advanced the material, the nature of cutting and slicing will wear down the blade's edge over time. The frequency of sharpening will depend on factors such as the type of steel, the quality of the knife, how often it's used, and the cutting surface it encounters.
Proper knife maintenance, including regular honing and occasional sharpening, is essential to keep any knife performing at its best. Honing with a honing rod or steel helps realign the microscopic edge, temporarily restoring sharpness between sharpenings.
In summary, while there are knives made from strong and durable materials, no knife will last forever without ever needing to be sharpened. Regular maintenance and sharpening are necessary to keep a knife's edge in optimal condition, regardless of the materials used in its construction.