The purpose of casting deformation of titanium and titanium alloys is, firstly, to obtain a design that meets the requirements of

casting

Part shape and size, the second is to make the casting microstructure and the use of performance to meet the design specifications required. So is the titanium alloy in the casting deformation formed during the bad microstructure is difficult to improve. Therefore, before developing the casting process, we must understand the casting process characteristics of titanium alloys. Titanium alloy casting process characteristics mainly include the following three aspects.

1. Deformation resistance is large

Deformation resistance is one of the significant characteristics of titanium alloy casting deformation. Compared with other alloy structural steel, in the same casting deformation temperature conditions when deformation, titanium alloy deformation resistance is large, with the casting deformation temperature decreases and rises rapidly. Therefore, due to the high deformation resistance of titanium alloys, a slight decrease in temperature during casting deformation of titanium alloys can also lead to a significant increase in deformation resistance. Therefore, the selection of a reasonable casting deformation temperature is the first task of titanium alloy casting.

2. Poor thermal conductivity

Poor thermal conductivity is another significant feature of titanium alloys, part of the thermal conductivity of titanium alloys. Poor thermal conductivity makes titanium alloy billet heating out of the furnace surface cooling faster than the internal, if improper operation will cause a relatively large temperature difference inside and outside the billet, intensifying the titanium alloy in the casting deformation process inside and outside the billet deformation is not uniform, will seriously affect the service life of titanium alloy castings and reliability. Therefore, fully preheat the tools in direct contact with the titanium alloy billet, such as casting moulds and clamps, is a very important work in the production of titanium alloy casting.

3. High viscosity and poor flowability

Due to the viscosity of titanium alloy and poor mobility, titanium alloy casting deformation must be strengthened when lubrication, otherwise it will produce sticky mold and material reflux phenomenon, but also due to the increase in friction makes the deformation resistance increased significantly, and sometimes because of the sticky mold and tear the casting. Experimental research results show that: under the condition of no lubricant, titanium alloy high temperature upsetting friction coefficient of 0.5, when using glass lubricant, titanium alloy high temperature upsetting friction coefficient of 0.04 ~ 0.06. Therefore, titanium alloy casting using a reasonable lubricant is an important measure to protect the quality of titanium alloy castings.