Exploring the Quenching and Partitioning Heat Treatment in a Fe-alloyed Titanium Alloy: An in-situ and ex-situ Approach

Description

Titanium alloys and steels, although chemically rather different, share some similarities in their metallurgical behavior. For example, the interplay of martensitic structures within a ductile matrix phase, such as austenite in steels or the β-phase in titanium, leads to the overlapping applicability of some rules and treatments for both metals. These structural similarities motivate the exploration of the effects that quenching and partitioning (Q&P) heat treatments have in the realm of titanium alloys. The Q&P process was initially developed to enhance the mechanical properties of advanced high strength steels by stabilizing the retained austenite matrix through the redistribution of interstitially dissolved carbon from the martensite phase into the austenite. In comparison to conventional Quenching and Tempering treatments and dual phase steels, this results in an increase in strength with consistently high elongation or, conversely, an increase in elongation with consistently high strength. This achieves a balance between high strength and good ductility.
With this heat treatment being well established in steels, the question arises, if such a primary phase transformation would also be applicable to Ti-alloys. As it is equally conceivable to induce martensite upon solution heat treatment and subsequent quenching and decompose it in a partitioning step, where β-stabilizing elements redistribute into the softer β-matrix. Especially, additive manufacturing (AM) could benefit strongly from such a heat treatment, as many Ti-alloys face the issue of relying on thermo-mechanical treatments for a good strength-to-ductility balance. In the AM context this means that plastic deformation must be introduced already during manufacturing in every individual layer, which hence increases complexity and costs. The application of Q&P could finally balance out the tense relationship between high strength and good ductility in AM Ti-alloys without relying on traditional thermomechanical treatments.
To investigate the feasibility and impact of Q&P treatments in titanium alloys, a series of experiments were conducted. These include synchrotron X-ray diffraction to track the phase transformations during the Q&P treatment and dilatometer compression tests on untreated and Q&P-treated material with microhardness measurements to evaluate its effects on the mechanical properties. Further, scanning electron microscopy was used to characterize the undeformed microstructures. The combination of these techniques provides detailed insights into the phase evolution and microstructure, clarifying the occurrence and exploitation potential of the Q&P effect in Ti-alloys.

Period	16 Sept 2025
Event title	FEMS Euromat 2025
Event type	Conference
Location	Granada, SpainShow on map
Degree of Recognition	International