Vacuum single crystal directional solidification furnace

                             Vacuum single crystal directional solidification furnace

Vacuum single crystal/directional solidification furnace is using the medium frequency induction heating to melt metals or alloys , specially designed holding furnace and cooling system are formed thermal gradient, By modern equipment directionally solidified and single crystal parts of the pull-down mechanism to get maximum temperature gradient and the formation of the solidification interface, it adopts a a structure specifically designed to meet the requirements of the temperature gradient.Application field:production of high-temperature aerospace materials.

Vacuum Induction Melting

       

Vacuum Induction Melting

 
Vacuum induction melting (VIM) utilizes electric currents to melt metal within a vacuum. The first prototype was developed in 1920.One of the only ways to induce a current within a conductor is through electromagnetic induction. Electromagnetic induction induces eddy currents within conductors by changing the magnetic field. Eddy currents create heating effects to melt the metal. Vacuum induction melting has been used in both the aerospace and nuclear industries.
History
E.F. Northrup built the first prototype of a vacuum induction furnace in 1920 in the United States of America. In 1923, German scientist Wilhelm Rohn continued to advance the VIM technology along with founding the Heraeus melting facility. Medium frequency furnaces were seen soon afterwards in England and Sweden in 1927.The process was initially developed to refine certain special metals such as cobalt and nickel. As these metals and alloys became more common, the process of VIM became more widely used. VIM now helps to melt a variety of metals for aircraft and nuclear applications.
Procedure
Vacuum induction melting uses currents within a vacuum to melt metal. VIM involves placing a core-less induction furnace into a vacuum chamber.The heat used to start the melting process comes from an induced current called an eddy current. The melting and casting operations are then carried out at low pressures to control the entire alloy chemistry process.
Uses
VIM was usually used for refining high purity metal and alloys. VIM is now becoming more popular due to the variety of uses now available. The commercial production of nickel titanium alloys utilizes VIM to its full extent. Other examples of using VIM include melting steels for nuclear applications, cobalt alloy for medical applications, and both high purity copper alloy and clean magnetic alloy for high permeability.The process of VIM can even begin electro-slag remelting, which can remelt electrodes.
Nickel titanium
VIM is the most widely used process for the production of nickel titanium alloys. When producing nickel titanium, the process of VIM using a hot graphite crucible sometimes causes carbon contamination which causes some of the titanium ions to form titanium carbide (TiC). These TiC particles change the transformation temperature along with the strength of the alloy. This is one drawback with the process of vacuum induction melting in graphite.

Thermocouple select for vacuum furnace

   Thermocouple select for vacuum furnace

Thermocouple temperature measurement at a specific vacuum: inexpensive metals, precious metals and refractory metal thermocouple characteristics, selection and application of tungsten-rhenium thermocouples detailed discussion of industrial classification, vacuum furnace for thermocouple configuration and installation, vacuum Profile factors furnace temperature accuracy, imports thermocouple localization studies, results showed: Domestic vacuum furnace for thermocouple can replace expensive imported thermocouple.

Vacuum Furnaces for Heat Treating, Brazing and Sintering Introduction

 Vacuum Furnaces for Heat Treating, Brazing and Sintering Introduction

 processing temperatures that are more efficiently accomplished by electric vacuum furnaces.  Further-more, the food and medical instrument industries have become attracted to the“bright” non-oxidized  finish
on parts heat treated by vacuum furnaces, which eliminates a cleaning  step. There are a wide  variety of electric and fuel-fired furnace types  used for materials processing. Each furnace type has advantages and disadvantages depending on the process  being conducted. Selection
of the furnace type  depends on the type and volume of  material being processed,the process economics, and the user’spreferences. One  furnace type gaining increased usage is  the electric vacuum furnace (Figure 1).  The connected electric load for this type of  furnace is typically
in the range of 40 kW  to 300 kW.
Applications
 Electric vacuum furnaces  can provide this level of quality. Also, the automotive industry’s switch to  lighter, stronger materials has created  a need for higher Process Fundamentals
Applications for these  high-temperature electrically  heated
vacuum furnaces include:
Electrically heated vacuum furnace technology has  eliminated environmental problems associated with  salt bath furnaces. Electric  vacuum furnaces also provide more precise control than traditional gas-fired furnace  technology.In addition, more demanding  quality requirements for  high temperature processing, such as  that imposed by the aerospace industry,  have pressured the heat treat industry  for continuously improved reliability and  repeatability.