The main problem with your project is oxidation of aluminum and titanium. Powders of these elements are always oxidized and these oxide layers cannot be reduced by carbon when temperatures are below 1500°C. In this way, carbon does not come into contact with metal and no carbides are formed. In the course of heating, the oxide layers on Ti and Al particles become thicker and thicker despite an argon atmosphere, because a low oxygen partial pressure is present even in the best argon.

For the reasons given above, a synthesis of Al and Ti carbides from metals is only possible when temperatures are so high that the reactions of Al and Ti oxides with the carbon take place. Such temperatures (from 1800°C) are realized in industrial production in electric arc furnaces.

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The synthesis of Ti3AlC2 and other MAX phase materials typically involves heating a mixture of elemental powders under an inert atmosphere at high temperatures, often in a tube furnace. The specific synthesis conditions, including temperature, heating rate, holding time, and the type of furnace, can all influence the outcome.

If the conditions are met, it is theoretically possible to synthesize Ti3AlC2 in an inert box chamber furnace. Still, there might be a few challenges compared to using a tube furnace.

• Uniformity of Heating: Tube furnaces generally provide more uniform heating along the length of the tube, which could lead to a more uniform reaction and higher yield of the desired product. In a box furnace, there might be temperature variations within the chamber, which could affect the reaction.
• Atmosphere Control: Tube furnaces allow for a continuous flow of inert gas, which can help to maintain a more stable and controlled atmosphere. Although purging with argon can create an inert atmosphere in a box furnace, there could be more potential for contamination or oxidation, especially over longer reaction times.
• Synthesis Parameters: The synthesis of Ti3AlC2 usually requires high temperatures (around 1400-1500°C), a slow heating rate (to avoid rapid reactions that can lead to impurities), and a sufficiently long holding time at the maximum temperature (to ensure complete reaction). You mentioned that you had tried various temperatures, heating rates, and holding times, but it might be necessary to optimize these parameters further.
• Effect of Starting Materials: The purity and particle size of the starting materials can also affect the reaction. Make sure your powders are well mixed before heating.

Regarding the absence of characteristic Ti3AlC2 peaks in your XRD pattern, it's possible that Ti3AlC2 is not being formed, or that it's being formed but is being obscured by other phases or impurities.

If you're not already doing so, you might want to use a more sensitive method to check for the presence of Ti3AlC2, such as Rietveld refinement of your XRD data, or TEM/SAED for microstructural examination.

You may want to refer to some of the following literature for more detailed information about the synthesis of Ti3AlC2:

It might also be helpful to consult with a materials scientist or a specialist in MAX phase synthesis for more specific advice about your situation.

Thanks for your answer Joshua Depiver, as far as our furnace is concerned, I did not communicate properly that there is a continuous flow of Argon gas rather than a single time purging at the beginning only. Rather, argon gas flows through the entire heating cycle.

Secondly, you mentioned the purity of starting powders. I got their XRDs and compared their peaks to the standard cards which were found to be in good accordance.

You also mentioned regarding the well mixing of the powders. We ball mill our starting powders. Can you please guide if there is anything specific we need to focus on when the powders are milled?