# Effect of Si and Holding Time on Ti2Al20La Phase in Al-Ti-La Intermediate Alloy

## TL;DR

This paper studies how adding silicon and varying holding time affects the Ti2Al20La phase in an aluminum-titanium-lanthanum alloy.

## Contribution

The study reveals how Si and holding time alter the Ti2Al20La phase's content, shape, and structure in Al-Ti-La alloys.

## Key findings

- Adding 2.3 wt.% Si reduces Ti2Al20La phase volume fraction from 21% to 4% and aspect ratio from 2.3 to 2.0.
- With increased holding time, Ti2Al20La phase content and size decrease, while La-Si binary phase content increases.
- Al11La3 dissolves and disappears as holding time increases.

## Abstract

The effects of holding time and Si on the content, shape size and structure of Ti2Al20La phase in Al-Ti-La intermediate alloy were investigated by an X-ray diffractometer, scanning electron microscope and transmission electron microscope. The results show that the volume fraction and aspect ratio of Ti2Al20La phase in Al-Ti-La intermediate alloy decrease significantly, from 21% and 2.3 without Si addition to 4% and 2.0 with the addition of 2.3 wt.% Si at a holding time of 15 min at 750 °C, respectively. The Si element will attach to the Ti2Al20La phase and form La-Si binary phase at the grain boundary of α-Al. With the increase of holding time from 15 min to 60 min, the content of Ti2Al20La phase in the alloy gradually decreases and the size decreases significantly. Meanwhile, Al11La3 will dissolve and disappear, while the content of La-Si binary phase increases, and part of Ti2Al20La phase transforms into Ti2(Al20−x,Six)La phase.