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discover become lose cut damage coat cut cause mean need
use get happen be create lose make cut fail aim
Scientists from MIT have why razor blades blunt after repeated use. They did research into why razor blades their sharpness. Razor blades are 50 times harder than the hairs they . Even though human hair is 50 times softer than the metal of a razor blade, the hair the edge of the blade. Razor blades are made from stainless steel. They are usually with tougher materials like hardened carbon. The MIT scientists said that each time a blade a hair, the hair tiny amounts of damage. A blade usually cuts thousands of hairs in one shaving session. This the life of a razor blade is limited and will to be replaced regularly.

The researchers powerful microscopes to find out how hair damages a razor blade. They a close-up view of what during a shave when the blade cuts a hair. The blade gets damaged in a variety of ways. One way that a single hair a tiny chip on the edge of a blade. This chip becomes bigger as it cuts more hair. After more shaving, the blade its ability to cut cleanly and becomes blunt. A researcher said: "We are metallurgists and want to... better metals. In this case, it was intriguing that if you something very soft, like human hair, with something very hard, like steel, the hard material would ." He said his team is " to solve an important engineering problem".

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