I. Copy the underlined words and word-combinations, translate them into Ukrainian and learn them.

II. Fill in the following table using the text.

Functions of the main elements of the factory

Lasers

One of the main characteristics of laser radiation is its intensity. From the invention of the laser in the 1950’s it was recognised that intenselaser beams might be a good way to deposit large quantities of energy in materials for manufacturing purposes. That potentiality has now become a mature technology. Over the past decade high-power lasers have been used in many manufacturing processes: the welding of automobile parts, electronic devices and medical instruments; the heat-treating of automobile and airplane parts to improve their surface properties; the cutting of sheet metal in the punch and die industry, and the drilling of small cooling holes (.007 to.05 inch) in airplane parts. In all these operations laser systems have made production lines more efficient and have reduced costs.

In manufacturing lasers serve basically as devices capable of applying an extremely high flux of energy to the surface of a workpiece. In this role they have significantadvantages over such conventional heat sources as flames, torches, electric arcs and plasma jets. Among these advantages are a product of higher quality (in terms of better performance and a reduction in the number of parts that have to be reworked or scraped); reduced outlays for materials, labour and processing; high productivity (with resulting reductions in floor space and depreciation costs); a better working environment, and the flexibility and versatility of the laser and the production system based on it.

It is becoming common to speak of two classes of high-power lasers, light and heavy. The classification depends mainly on the power. The light lasers operate in the range from a few tens of watts to a few hundred. They serve in such work as cutting and drilling ceramic substrates in the electronics industry, drilling rubies in the watch-making industry and cutting not only metal, but also cloth, plastics and wood in a variety of other industries.

The heavy lasers range in power from a few kilowatts to a few tens of kilowatts. The heavy lasers in manufacturing serve in heavy-duty processing such as the welding of pipelines, the welding of automobile parts and the heat-treating of the surface of such parts as crankshafts and the cylinder walls of large diesel engines. The treatment hardens the surface, increasing the resistance of the part to wear. Most of the heavy-duty lasers are carbon dioxide lasers operating in the continuous mode.