The efficiency of the melting of titanium alloys’ raw material directly affects whether the performance of the finished product after the subsequent processing can meet product requirements. The quality of titanium ingot casting exerts a decisive impact on the materials in the subsequent cooling and heating processing in terms of their microstructures and properties.
The quality of titanium ingots and titanium alloy ingots can be measured mainly from the following aspects:
①whether the chemical composition of different parts of the ingot is well-distributed and uniform;
②whether the amount of major impurities (Fe, O, etc.) are controlled in an appropriate range;
③ whether defects such as inclusions, segregation, pores, cracks, craters and shrinkage cavities are inside the ingot;
④ whether the ingot surface is smooth and without cold shuts, the size of its resection volume of the head shrinkage cavities.
The titanium products ZircoSCM provides commonly employ the following methods of titanium alloy smelting :
1. Vacuum Arc Remelting (briefly referred to as VAR method)
Currently producing titanium ingots and its alloy ingots is mainly using this method. VAR method’s notable feature is its low power consumption, high melting rate and good quality reproducibility.Ingots produced by VAR have good crystal structures and uniform chemical composition.Usually, finished ingots should be obtained by VAR method and be remelted at least twice. VAR method is ZircoSCM’s standard industrial melting of titanium and titanium alloy .
2. The Electron Beam Cold Hearth Melting method (referred to as EBCHM method)
Electron Beam Melting (abbreviated EB) is a technological process that makes use of the energy of high-speed electrons to make the material itself to generate heat for melting and refining. A EB furnace with a cold hearth is called EBCHM. EBCHM boats advantages that traditional melting methods do not have:
(1) It can effectively remove high density inclusions (HDI) like tantalum, molybdenum, tungsten, tungsten carbide and low-density inclusions (LDI) like titanium nitride;
(2) It can accept a variety of feeding methods and its titanium scrap recycling is easier, which can use wastes that can not be used during other melting methods and still obtains pure titanium ingots, significantly reducing the cost of the product;
(3) It can be sampled, analyzed and tested directly in the metal liquid;
(4) It can be used to produce special-shaped ingot blanks, reducing production processes and material consumption and improving the yield.
ZircoSCM has achieved wide-range automatic process control in these two titanium smelting methods, including process parameters (speed of melting, temperature distribution during melting and solidification process, changes of components in smelting, the degree of the removal of insoluble inclusions, etc.) and quality.
For more information about the terms of the titanium alloy smelting, please contact us.