The molten metal pool in vacuum arc melting furnace has much influence on the quality of ingots. Its influence is much more pronounced in melting titanium alloys from the compacted electrode than in other metals. During melting titanium alloy in vacuum arc melting furnace, the shape and temperature profile of molten metal pool and temperature in water-cooled copper mold were measured.
Examining these data results in the following conclusions.
(1) Temperature in arcing area is not affected by melting current and it is about 2 000°C.
(2) Surface temperature of molten metal is estimated at about 2 200°C and the temperature under the surface decreases by approximately 200°C/cm. The temperature distribution in the upper part of molten metal pool is not affected by melting current.
(3) Heat transfer coefficient is 0.04 cal/cm²·s°C at the top of ingot and less than 0.02 cal/cm²·s°C under 30 mm from the ingot top.
(4) Metal pool depth is influenced mainly by melting current. The metal pool shape has been allowed to estimate by analysis of heat transfer with boundary conditions investigated.