Hot And Cold Technologies

Nov. 21, 2006
This issue of American Machinist has articles on technologies that are both hot and cold.

This issue of American Machinist has articles on technologies that are both hot and cold. Associate Editor Larry Haftl reports on using industrial lasers to provide heat treating that can be so accurate it can define specific lines — not areas — of case hardened bearing surfaces for a wide variety of parts. These lasers are taking heat treatments to new levels.

Rather than heat treating an entire part in batches or individually in an oven, lasers can be focused on the part's specific bearing surface, and can closely define that bearing surface. While there is an obvious economic benefit — shops won't have to send hundreds of parts out for heat treating if they can zap a bearing surface while the part is still on their machine — the objective really is to provide a better part — with a laser, the exact depth and dimension of the bearing surface can be marked and treated, giving the parts longer life when they are put into service.

Meanwhile, we also have a report on a new cryogenic cooling process that uses liquid nitrogen to make cutting tools extremely cold in hard turning operations. The liquid nitrogen also keeps the workpiece cool so that close tolerances can be maintained.

This is a new process that has yet to be made commercial, but its developers are optimistic that it can replace rough grinding for many applications and eliminate nearly 95 percent of the time needed to rough a part.

The process has been used for five years to machine the hard, heavy-duty rolls used in steel processing, and it is being adapted for hard turning and smaller parts.

How cold is it? The liquid nitrogen boils at 320 degrees below 0 F (- 196 degrees C).

Contrary to what you may think, that cold liquid actually strengthens and toughens ceramic cutting tools, providing a longer tool life while allowing less-expensive tooling to be used to cut materials with hardness ratings of 78 Rc and higher.

Both of these technologies are going to require additional investments, but both of them promise to provide returns on the investments that shops put into them, either through reducing the time and costs when compared to the technologies that are currently used, or by improving the performance of the parts that are made with them.

Lastly, we are trying to boost the submissions for one of our perennially favorite features — Practical Ideas.

This self-help column — in which readers give us their best ideas and tricks of the trade to share with other readers — has been a feature in American Machinist for more than a century.

In recent years, the number of people who have supplied us with ideas has fallen off, and we quietly eliminated the reward that we were paying for ideas.

We are going to reinstate the reward for ideas in 2007, and we are hoping that our readers take up the challenge and come forth with thoughts that can help other shops.

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