In this study, in situ Al₂O₃-reinforced Ti₃Al composite was fabricated after 8 h of milling and sintering at 850 °C. A mixture of TiO₂ and Al powders were mechanically milled in a planetary mill, cold-compacted and sintered under a protected argon atmosphere. The microstructure and microhardness of the Al₂O₃ embedded in Ti₃Al matrix at both room and elevated temperature has been reported. The obtained results showed that the Ti₃Al/Al₂O₃ composite was successfully synthesized via the powder metallurgy method. Ti₃Al phase and Al₂O₃ particles were formed after 8 h of milling and sintering at 850 °C. The microstructure formation of round and uniformly distributed Al₂O₃ particles in the Ti₃Al matrix improved the microhardness of the composite. At normal temperature, the microhardness of the material measured about 11.5 GPa. Meanwhile, at elevated temperatures, from 600 to 800 °C, it decreased from 4.18 GPa to 3.15 GPa.

Thermodynamic and experimental studies was carried out on the process of Thanhhoa dolomite reduction to produce magnesium. Thermodynamically studied on the effect of pressure and temperature on reduction was carried out together with verification experiment. Results show that at appropriate temperature and vacuum pressure, Thanhhoa dolomite can be reduced using ferrosilicon as the reductant. The higher level of vacuum, the lower temperature required for reduction. Thermodynamic calculation pointed out that at a vacuum pressure of 600 Pa, the reduction temperature could be as low as 1140 °C. Experiment results indicated that at although reduction could be done at 1150 °C, the process efficiency was low, generally below 20%. Process efficiency enhanced as temperature increase and reaches the highest value of 85,8% at 1250 °C (25 wt.% ferrosilicon). The amount of ferrosilicon used also has influenced the process efficiency. After three hours of reduction, the obtained magnesium was very high in purity, 99.3%.

The magnesium and magnesium alloys has applied widely in different industrial aspects in Vietnam in the modern life. Especially, the products from magnesium alloys implementing in the automotive have increased rapidly since the car elements tend to be generated by the light alloys in order to save the fuel. However, in the current time, Vietnam has no factories to produce the magnesium to adapt the domestic demand although it owns an enrich resource of raw materials. This research indicates the possibility of using the dolomite ore in Thanhhoa – Vietnam to make the magnesium as well as evaluate the primary factors like recovering temperature, reducing agent rate, recovering time having effect on the reduction efficiency of Thanhhoa dolomite by metallothermic method in vacuum (Pidgeon Process). This is basic process, low investment and suitable for the small and medium scales in Vietnam. The experiment includes heating, indicating the chemical ingredients and recovering experiment on the dolomite after calcination (dolime) by using ferrosilicon. The thermodynamic model is created to estimate the recovering efficiency in the Pidgeon. The result shows that the CaO/MgO molar ratio of calcination dolomite in Thanhhoa is nearly 1.5 which is suitable to produce magnesium in the case of highly-required efficiency and pureness. Besides, the result from the furnace of the experiment is lower than the one in the model. The samples are set up to check the influence of the rate of ferrosilicon in the compound. The result indicates that the ideal efficiency reaches 85 % with 30 % ferrosilicon. Moreover, the study confirms that the optimal operating conditions in this process are recovering during three hours at 1200 °C and 100 Pa pressure. This result proves the potential application of Thanhhoa dolomite in the industry suitable with the current condition in Vietnam