EB_2011.qxd table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:11.00pt "Impact", sans-serif; } .font1 { font:25.00pt "Impact", sans-serif; } Electron Beam Melting (EB) Electron Beam Melting Processes and Furnaces

EB_2011.qxd table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:7.00pt "Impact", sans-serif; } .font1 { font:9.00pt "Impact", sans-serif; } .font2 { font:18.00pt "Impact", sans-serif; } Electron Beam Melting Electron beam melting is distinguished by its superior refining capacity and offers a high degree of flexibility of the heat source. Thus, it is ideal for remelting and refining of metals and alloys under high vacuum in water-cooled copper molds. Today the process is mainly employed for the production of refractory and reactive metals (tantalum, niobium, molybdenum,...

EB_2011.qxd table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:7.00pt "Impact", sans-serif; } .font1 { font:8.00pt "Impact", sans-serif; } .font2 { font:9.00pt "Impact", sans-serif; } Process Variations The high degree of flexibility of the EB heat source has spawned the development of several remelting and refining methods. ■ Drip Melting is the classical method for processing refractory metals such as Ta and Nb among others. Raw material in form of bars is usually fed horizontally and drip-melted directly into the withdrawal mold. The liquid pool level is maintained...

EB_2011.qxd table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:7.00pt "Impact", sans-serif; } .font1 { font:8.00pt "Impact", sans-serif; } .font2 { font:9.00pt "Impact", sans-serif; } Process Control EB furnaces operate in a semi-automatic control mode. Even with the highly sophisticated computer controlled process automation, operator supervision of the process and manual fine tuning are still required. Process automation includes: ■ vacuum pump system scheme; ■ vacuum pressure control; ■ material feed rate and ingot withdrawal rate; ■ processor-based high voltage...

EB_2011.qxd table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:7.00pt "Impact", sans-serif; } .font1 { font:8.00pt "Impact", sans-serif; } .font2 { font:9.00pt "Impact", sans-serif; } Electron Beam Guns and Melting Furnace Types The following systems are available: ■ Electron Beam Guns a sries of EB guns with 60, 300 and 600-kW beam power at 25-45 kV. ■ EB Drip-Melt Production Furnaces for production of refractory metal ingots up to 400 mm in diameter and 3,000 mm length, beam powers up to 2 MW with 2, 3 or 4 guns. ■ EB Cold Hearth Production Furnaces for production...

EB_2011.qxd table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:7.00pt "Arial", sans-serif; } .font1 { font:8.00pt "Arial", sans-serif; } .font2 { font:5.00pt "Impact", sans-serif; } .font3 { font:6.00pt "Impact", sans-serif; } .font4 { font:7.00pt "Impact", sans-serif; } .font5 { font:8.00pt "Impact", sans-serif; } .font6 { font:9.00pt "Impact", sans-serif; } EB Features ■ ALD offers lectron beam guns of 60, 300, 600 and 800 kW power with highly advanced beam deflection controls; ■ System designs are implemented with melting powers above 3,600 kW; ■ Ceramic-free melting...