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Martensitic Stainless Steel (AISI420) MSS are vastly used because of their properties conventional which mix good mechanical and corrosion resistance. Cryogenic up to -196°C for different soaking time and heat treatments at (1000,500,200°C) for 15 minutes is one of the ways that used to enhance mechanical properties of these steels by means transformation of retained austenite, deformation regarding martensite then carbide refinement. the result showed an increase in tensile strength of samples that were treated cryogenically and tempered at 500°C was 933 (MPa) compared to samples that just treated conventionally in austenitizing and tempering at the same temperature that was 880 (MPa). The hardness values increased considerably to 414HV and 321 HV for the specimen that tempered at 200°C and 500°C respectively, precipitation of small carbides was observed that this is responsible for the improvement in the mechanical properties of the material.

Taguchi method and a regression model have been developed to study the effect of AL% filler contents on the glass/polyester honeycomb sandwich panel behavior subjected to impact load. Using the standard Taguchi’s array L9, analysis of means (ANOM) including main effects of S/N ratio and experimental response, ANOVA was used to determine the optimum process parameters with its significant factor. Three parameters as controlled variables have considered: AL%, mass, and height with three levels for each of them in destructive and non-destructive tests. The results show that for deflection: the mass has the highest contribution at (58.2439%) followed by the AL% filler (21.3718%). The AL% has the highest contribution for the deformation, with a percentage of (89.1144%) followed by the height and mass with a relative contribution to each other. The regression model has a good prediction, with a perfect correlation between the output and input variables. The coefficient of determination and the correlation coefficient are 89.88 % and 0.94, respectively, for deflection, while for deformation are 81.45 % and 0.9, respectively. The average error MAPE equals 6.19 % and 12.128 % for deflection and deformation, respectively. There is a strong relationship between the variables depending on the correlation coefficient, which presents as 0.94 for deflection and 0.9 for deformation. Confirmation results show that the experimental and predicted values were close to each other.

This study investigated experimentally the wear volume loss of the epoxy reinforced by (Al) and (Al 2 O 3 ) particles of grain size ( ≤ 30 µm) with different four volume fractions of the reinforcements which are (3 %, 6 %, 9 %, and 12 % Vol.). Pin-on-Disc wear test were conducted to exam the wear volume loss behavior of the composite specimens. The wear test results indicated that the wear volume loss of the specimen increases with the increase of the applied load and sliding time, while it decreases with the increase of the volume fraction of the reinforcing material. Also the results show that the average volume loss of the epoxy reinforced by (Al) was higher than reinforced by (Al 2 O 3 ) by the value was (45 % ) at volume fraction (= 6 %), sliding speed (V s =2 m/sec.) and sliding time ( T =300 sec.