Titanium and titanium plate solid solution and aging treatment

Solution and aging treatment is a primary means of heat treatment of titanium and titanium reinforced . It is actually divided into solution treatment and aging treatment carried out in two steps . Solution treatment is to titanium and titanium alloy heating, insulation and rapidly cooled to room temperature operation. Aging treatment after solution treatment is the workpiece at a medium temperature range (450-550 ℃) holding a certain time after the air-cooling operation. This heat treatment method can be applied to nearly α alloy , α + compound alloy , α + β alloy and heat-treated β alloys.
Solution treatment process selection
The purpose of titanium and titanium alloy solution treatment can be effective is to keep strengthening the metastable phase . For near α and α + β type alloys , the purpose is to retain the solution treated martensite α ', α " or the amount of metastable β phase . Solution treatment temperature is usually lower than the phase transformation point selection 40-100 ℃ at this time , a certain proportion of primary α phase β -phase . β produce metastable phase in the subsequent rapid cooling . generally require cooling water quenching oil quenching may also be used it should be emphasized that these two alloys hardened be sure to quickly . delayed quenching time ,medical titanium plate product temperature decreased rapidly , α -phase nucleation in the first phase on the original β grain boundaries and grew up on the mechanical properties of hardened state . gives the quench delay operations on TC4 alloy and affect performance . usually require quench delay time can not be more than 10 seconds on the sheet even more demanding. Additionally, the complex shape of the workpiece or sheet should be taken to prevent deformation hardening .
The purpose of metastable alloy solution-treated in order to preserve the metastable β phase . Solution treatment temperature is usually selected in the α + β / β transformation point 40-80 ℃. Cooling can be air-cooled and water-cooled . To prevent deformation hardening and improving economic results generally use air cooling.
Α + alloy for some compounds , the purpose is to keep the processing solution supersaturated solid solution of β . Solution treatment temperature is generally selected just below the eutectic temperature. Such as Ti-2Cu alloy eutectic temperature of 798 ℃, the solution treatment temperature selection at 790. ℃ Cooling optional air cooling.
Incidentally , since the titanium and titanium alloy produced in the solution treated martensite on replacement elements are oversaturated not result in a large lattice distortion ,titanium pipe such as titanium martensitic steels martensitic not so hard . In addition, the intensity of metastable β phase is relatively low . Therefore , hardenability titanium and titanium alloy does not mean depth of hardening after quenching , but rather the depth of those retained in the subsequent aging in Asia can cause hardening of the stable phase. Because titanium martensite on cooling rate to be much more sensitive , it is hardening during tempering is also limited, so hardenability titanium and titanium alloy mainly refers to the depth of retained metastable β phase.