Too high a toughness sintering temperature on the surface of the titanium plate will speed up the formation of titanium carbide grains. The final sintering temperature of titanium carbide high manganese steel bonded cemented carbide is generally 1420℃. The sintering temperature should not be too high, so that the bonding phase becomes a liquid phase and the metal is lost, so that the hard phase is adjacent and converged to form a source of fragmentation.
Of course, the sintering temperature should not be too low, otherwise the alloy will be underburned. In addition to the aforementioned need to control the sintering temperature and speed, the vacuum in the furnace enters the liquid phase sintering stage. It is also necessary to control the vacuum degree in the furnace during sintering. Due to the excessively high vacuum degree, a large amount of liquid phase metal will volatilize, forming component segregation. Especially in the three stages of degumming, recovery and liquid phase sintering, the heating rate during sintering is not suitable for such alloys.
The surface and internal toughness of the titanium plate should be strictly controlled in the heating rate and holding time. Because in the low-temperature degumming stage, the compaction releases the compression stress and the forming agent volatilizes. If the heating speed is fast, the forming agent is too late to volatilize and becomes steam after liquefaction, causing the compaction to burst or crack;
It is necessary to allow sufficient time for the compact to remove the volatiles and oxygen in the raw material powder (such as Mn2Fe master alloy); when entering the liquid phase sintering stage, the heating rate must be slowed down to fully alloy the compact. The sintering principle of steel-bonded cemented carbide is the wetting principle, allowing the liquid phase to fully wet the solid phase (hard phase), otherwise the liquid phase metal FeMn will be precipitated on the surface of the compact and even lost.
