In the present paper, Ti/SiC composite materials have been fabricated by using Selfpropagating high temperatures synthesis (SHS). SHS is a well-known method for fabrication of the advanced materials in a single step process and is based on a system that involves an exothermic combustion. Titanium powder (Ti/p) with average particle size 100 µm and Silicon carbide (SiC) with 100-320 µm particle size range has been mechanically activated by attrition mill. Powder weighing has been prepared in accordance to the size of each volume fraction where the ratios for Ti/SiC are 70:30% and 60:40%. The optimal density results were achieved in the volume fraction of 70:30% at 1000º C for 4.54 gr/cm 3 . The porosity test data has shown that the porosity value has been increased during the increasement of the SHS sintering temperature. The lowest porosity was produced at a volume fraction of 70:30% in a sintering temperature at 900º C with the corresponding value 2.36%. The highest and lowest hardness value varied from 194 HV to 40 HV. The results have shown that mechanical properties of the Ti/SiC composite materials have been increased in comparison to the commercially pure titanium substrate and almost close to mechanical properties of Al/SiC composite materials.

In this paper we have proposed an experimental study of the steel grains sizes effect on the shift frequency of the ultrasonic waves being propagated in steels. Ultrasonic testing has been used in most inspection services for different materials as non-destructive testing. The novelty of our research work has been focused on the investigation of the new method for determining microstructure evolution of metals by using ultrasonic signals in conjunction with changes in grain size and hardness of steels. Furthermore, we have studied the microstructure of steel types S355, S275, Corten B and S275N. The microstructure results of steels have shown the changes that have been undergone from thermal and mechanical processes by using the attenuation of ultrasound waves during non-destructive testing.

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