Surface Roughness Of Composites Research Articles

Polyethersulfone membrane embedded with amine functionalized microcrystalline cellulose

In this investigation, microcrystalline cellulose (MCC) was functionalized with metformin HCl using (3-chloropropyl)triethixysilane (CPTES) as a coupling agent. Polyethersulfone (PES) membranes were incorporated with different concentrations of modified MCC (MMCC) to enhance its affinity for heavy metals during filtration of aqueous solutions. The composite membranes were characterized via fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), Brunauer–Emmett–Teller (BET) method, porosity and contact angle measurements and mechanical analysis. The presence of MMCC in the host matrix was confirmed by FTIR. Although composites decomposed at lower temperatures, their thermal stability was sufficient to meet their performance requirements. DSC showed enhanced glass transition temperature (Tg) due to the interfacial interactions between membrane constituents which restrict the mobility of polymer chains. Microscopic imaging revealed higher surface roughness of composites compared to neat PES. Inclusion of MMCC increased the porosity and hydrophilicity of the membrane which consequently, higher permeability can be achieved.

Comparison of Genetic Algorithm and Taguchi Optimization Techniques for Surface Roughness of Natural Fiber-Reinforced Polymer Composites

Comparison of Genetic Algorithm and Taguchi Optimization Techniques for Surface Roughness of Natural Fiber-Reinforced Polymer Composites

RETROSPECTIVE ANALYSIS OF THE STATE OF DIRECT DENTAL RESTORATIONS AFTER ENDODONTIC TREATMENT

Endodontic treatment is accompanied by the loss of a significant amount of tooth crowns, which leads to a significant decrease in their strength characteristics. The restoration of endodontically treated teeth, as a rule, is carried out by the direct method, however, a unified approach regarding direct or indirect restoration has not yet been determined. The aim – retrospective analysis of the clinical condition of direct restorations of endodontically treated teeth. Materials and methods. 284 patients aged 25 to 60 years were examined; they studied the state of 888 previously performed direct restorations of the anterior and posterior teeth after endodontic treatment in a period of 2 to 10 years. Restorations were evaluated according to the adapted clinical criteria “integrity of the restoration”, “marginal fit of the material”, “marginal staining”, “anatomical shape”, “colour correspondence for the restoration”, “roughness of the surface of the material”, as well as the criterion “condition of the contact point” for located on the contact surfaces of the teeth of the restorations. Results. Of the 888 examined direct restorations, 760 restorations (85.6±1.18 %) were located in the posterior teeth, with 562 restorations in the molars (63.3±1.62 % of the total) and 198 in the premolars (22 , 3±1.40 %), and 128 restorations (14.4±1.18 %) were detected in the anterior teeth, while in the incisors - 80 restorations (9.0±0.96 %), in the fangs – 48 (3.5±0.76 %). 720 restorations (81.1±1.31 %) were made from photocomposite materials, 97 restorations (10.9±1.05 %) from chemical curing composites, 71 (8.0±0.91 %) from glass-ionomer cements . The most common violations were colour mismatch – in 511 restorations (57.5±1.66 %), marginal staining - in 470 restorations (52.9±1.68 %), surface roughness - in 357 restorations (40.2±1.0, 65 %). More often than others, in the reconstructions of their photocomposites and glass ionomers there was a colour mismatch, and surface roughness for chemical composites. Conclusions. For direct tooth restoration after endodontic treatment in 81.1±1.31 % of cases, photocomposite materials are used, less often chemical curing composites and glass ionomers. Of the violations of such restorations, the most frequent are colour mismatch, surface roughness and edge staining.

An experimental investigation of thrust force, delamination and surface roughness in drilling of jute/carbon hybrid composites

Purpose This paper aims to deal with the influence of cutting parameters on drill thrust force, delamination and surface roughness in the drilling of laminated jute/carbon hybrid composites. Design/methodology/approach The hybrid composites were fabricated with four layers of fabrics, which are arranged in different sequences using the hand-layup technique. Drilling experiments involved drilling of 6 mm diameter holes on the prepared composite plates using high-speed steel and solid carbide drill materials. Analysis of variance was used to find the influence, percentage contribution and significance of drilling parameters on drilling-induced damages. Scanning electron microscopy analysis was also conducted to understand the fracture behavior and surface morphology of the drilled holes. Findings The experimental study reveals that the most significant effect was the feed rate influenced the drill thrust force and the drill speed influenced both delamination factor and surface roughness of hybrid fiber-reinforced composites. From observations, the suggested combination for drilling jute/carbon hybrid composites is carbide drill, spindle speed of 1,750 rpm and feed of 0.03 mm/rev. Originality/value The new lightweight and low-cost hybrid composites were developed by hybridizing jute with carbon fabrics in the epoxy matrix with interplay arrangements. The influence of cutting speed and feed rate on delamination damage and surface roughness in the drilling of hybrid composites have been experimentally evaluated.

Chemical and Mechanical Roughening Treatments of a Supra-Nano Composite Resin Surface: SEM and Topographic Analysis

Background: Repairing a restoration is a more advantageous and less invasive alternative to its total makeover. The aim of this study was to analyze the effects of chemical and mechanical surface treatments aimed at increasing the roughness of a supra-nano composite resin. Methods: 27 cylindrical blocks of microhybrid composite were made. The samples were randomly divided into nine groups (n = 3). The samples’ surface was treated differently per each group: acid etching (35% H3PO4, 30 s and 60 s), diamond bur milling, sandblasting and the combination of mechanical treatment and acid etching. The samples’ surface was observed by a scanning electron microscope (SEM) and a confocal microscope for observational study, and surface roughness (Ra) was recorded for quantitative analysis. Results: The images of the samples sandblasted with Al2O3 showed the greatest irregularity and the highest number of microcavities. The surfaces roughened by diamond bur showed evident parallel streaks and sporadic superficial microcavities. No significant roughness differences were recorded between other groups. The difference in roughness between the control group, diamond bur milled group and sandblasted group was statistically significant. (p < 0.01). Comparison between the diamond bur milled group and the sandblasted group was also significant (p < 0.01). Conclusion: According to our results, sandblasting is the best treatment to increase the surface roughness of a supra-nano composite.

An evaluation of surface roughness after staining of different composite resins using atomic force microscopy and a profilometer.

The aim of this study was to compare the surface roughness of different composite resins using atomic force microscope (AFM) and a profilometer after storage in different solutions. Eight different composite resins were used in this study. Twenty specimens of each composite resin material were prepared using a 2-mm thick and 8-mm diameter stainless steel mold. After the composites had been placed in the mold, they were polymerized with a LED curing unit. The surfaces of all specimens were polished using aluminum oxide discs, and the specimens were then divided into four groups. The specimens in the experimental groups were stored in cola, coffee, or red wine, while the control group was stored in distilled water. Specimen surface roughness was examined after 30 days using an AFM and a profilometer, and the data obtained were subjected to analysis. Evaluation of the surface roughness of composite resins using a profilometer revealed no statistically significant difference between the groups, but significant differences were found using the AFM. The mean surface roughness of nanohybrid composites was lower than that of microhybrid composites. The surface roughness of the composite resins varies with storage in different solutions, depending on the organic matrix structure and inorganic fillers of the resin.

Effect of surface sealant on the surface roughness of different composites and evaluation of their microhardness.

The aim of this study was to evaluate the effect of a surface sealant on the surface roughness of different composites and compare their microhardness values. Sixty disc-shaped specimens were prepared and assigned to 6 groups (n =10). Groups were prepared as follows; Group 1 (Herculite XRV Ultra), Group 2 (Beautifil Bulk Restorative) and Group 3 (Filtek Bulk Fill Posterior Restorative). Groups 4, 5, and 6 were prepared by applying a surface sealant (BisCover LV) on the specimens in groups 1, 2 and 3. Surface hardness of the discs in group 1, 2, and 3 and surface roughness of the discs in all groups were measured using the Vickers hardness test and a profilometer, respectively. One-way ANOVA was used to test for differences among the groups. No significant differences were observed in the microhardness and roughness between the experimental and control groups for each restorative materials. Group 3 showed the highest surface hardness and group 4 showed the lowest surface roughness values. Using the BisCover LV resin after the polishing step has no significant effect on the surface roughness. The highest hardness values were obtained for the Filtek Bulk Fill Posterior Restorative after the polishing step. The smoothest surfaces were obtained for all experimental groups using the BisCover LV resin after the polishing step, Herculite XRV Ultra showed lower average roughness values than the other materials.

Influence of Milling Parameters on Surface Roughness of Al–SiC–B4C Composites

Surface roughness is one of the important factors which help to address the quality needs of composite materials, and it relies on the machining conditions. This paper carried out an experimental investigation to identify the influence of machining parameters on surface roughness of aluminum metal matrix composites. Stir casting technique is used to produce SiC- and B4C-reinforced aluminum composites with three different compositions. Using end mill cutter, the materials are machined with different combination of machining parameters. To assess the quality of machined surface, roughness of machined surface is measured with the help of surface roughness testing machine. The obtained results have been analyzed to optimize cutting parameters using Taguchi and ANOVA techniques. The experimental results confirm the order of most influential milling parameters as 0.1 mm/rev feed rate, 3000 rpm spindle speed and 0.2 mm depth of cut with maximum contribution percentages of 86.6%, 9.75% and 6.16%, respectively. This study would ensure the optimal parameters for quality products in terms of surface roughness.

Experimental study on the coefficient of restitution of grain against block interfaces for natural and engineered materials

The coefficient of restitution (COR) is an important input parameter in the numerical simulation of granular flows, as it governs the travel distance, the lateral spreading, and the design of barriers. In this study, a new custom-built micromechanical impact loading apparatus is presented along with impact experiments on engineered and natural materials. The COR and energy loss of various grains and base block combinations are studied, including fairly regular-shaped Leighton Buzzard sand (LBS) grains as a natural soil and granite or rubber as base blocks, apart from the use of engineered materials for the grains (chrome steel balls, glass balls) and blocks (stainless steel, brass). The repeatability of the new micromechanical impact loading apparatus was checked by impacting chrome steel balls on stainless steel block. In all the test combinations, the higher and lower values of the COR are found for granite block (ranging between 0.75 and 0.95) and rubber block (ranging between 0.37 and 0.44) combinations, respectively. For the tested grain–block combinations, lower values of COR were observed for impacts between materials of low values of composite Young’s modulus. However, within the narrow range of composite surface roughness of the tested grain–block interfaces no particular trend was observed in the COR values. Compared to glass balls and chrome steel balls, greater scatter in the COR values is observed for natural sand grains. This is due to the variation of the elastic and morphological characteristics among individual LBS grains.

Color Shift, Color Stability, and Post-Polishing Surface Roughness of Esthetic Resin Composites.

The aim of this study was to compare color shift, color stability, and post-polishing surface roughness of esthetic restorative materials. Twenty-five disc-shaped specimens (10 mm in diameter and 2 mm in thickness) from five esthetic resin materials (Z250XT, IPS Empress-Direct, G-ænial, Vit-l-escence, and Ceram.X) were fabricated. Color shift before and immediately after light-curing (∆E0) then color stability after immersion in tea, coffee, berry juice, and distilled water were measured using a spectrophotometer. Color changes were measured after 2 (ΔE2), 4 (ΔE4), 6 (ΔE6), and 8 weeks (ΔE8). Surface roughness values (Rq) were determined using an optical profilometer after polishing using a rotary polishing system. Data were analyzed using ANOVA and multiple comparison methods at 0.05 significance level. There were no significant differences between the tested materials regarding color shift except between Vit-l-escence and Ceram.X (p = 0.033). There was no significant difference between coffee and tea solutions (p = 1.0) and between berry juice and distilled water (p = 0.15). There was no difference between the tested materials regarding Rq (p = 0.057). Ceram.X was associated with the lowest ΔE8 values overall. Tested materials were comparable regarding color shift and post-polishing surface roughness. Susceptibility to staining was dependent on the material.

Surface properties and bacterial adhesion of bulk-fill composite resins

ObjectivesThe aim of the present study was to evaluate the Streptococcus mutans and Streptococcus mitis adhesion and related surface properties of bulk-fill resin composite. MethodsFour novel bulk-fill composite with different composition were used; Sonic Fill-2 (KSF), Filtek BulkFill (FBF), Admira Fusion X-tra (AFX), Beautifil Bulk Restorative (SBB) and a control group (glass) were included in the study. After standardized surface polishing procedure, surface properties of composite specimens were evaluated using surface roughness (SR) measurements by a profilometer, hydrophobicity and surface free energy (SFE) analyses, elemental and topographic analyses by SEM-EDS. To evaluate the bacterial adhesion, composite specimens were immersed in artificial saliva and mucin for pellicle development. After 1-h immersion, bacterial suspension was added to the pellicle-coated specimens, which were incubated at 37 °C in 5% CO2 atmosphere for 24 h. Adhered bacteria counts were determined as x108 Cfu/ml. Bacterial adhesion was also investigated using confocal laser scanning microscopy. ResultsNo statistically significant differences were found among bulk fill composites in terms of surface roughness while glass showed the lowest Ra values. The lowest contact angle values were found in the control group and Sonic Fill-2 while the highest SFE values were observed in these materials. No statistically significant differences were found between the S. mutans counts. For S. Mitis adhesion, the highest value was found in Sonic Fill-2 and no significant differences were observed between the other groups. ConclusionsSR of bulk-fill composite resins had no effect on bacterial adhesion. However, bacterial adhesion increased with higher SFE values. Clinical significanceAlthough the surface roughness of composites used in the study is similar, in clinically, S. mitis adhesion may be more in the KSF group because of high surface free energy.

Surface Roughness of Nanohybrid Composites with Different Monomers after Finishing and Polishing with Different Polishing Systems

Background: The most frequently used monomer in commercial composite resins is bisphenol A glycidyl dimethacrylate. Bisphenol A glycidyl dimethacrylate free monomer and the long chain dimer acid based monomer were considered as an alternative method to improve mechanical and physical properties of composite resins. Objective: To study the surface roughness of different nanohybrid composites with different monomer compositions after finishing and polishing with different polishing systems. Materials and Methods: 72 composite disk specimens were prepared and divided into 3 groups (n=24) according to the resin composite that were used (harmonizekerr,venusdiamondheraeuskulzerandn'duranceseptodont). Each group was subdivided into 4 subgroups (n=6) according to the polishing technique that was used (Jiffy natural universalwheelsultradent,sof-lexspiral wheels 3mespe,hilusterkerrorenhance systemdentsply). Atomic force microscope was used to measure surface roughness. Results: There was statistical significant difference in surface roughness measuring among differentn'durance,venusdiamondandharmonizegroups (Kruskal Wallis Test p<0.05). Post hock pairwise comparison revealed thatvenusdiamondshowed statistically significant higher surface roughness when compared with eithern'duranceandharmonize. Among the polishing systems,jiffynaturaluniversalwheelsproduce the least surface roughness. Conclusion: Different monomer compositions may have direct effect on the final surface polish of the restorative materials. Clinical significance: The use ofjiffy natural universalwheelsmay be found to result in the smoothest surface finish with the least clinical steps.

Evaluation of Surface Roughness, Hardness, and Gloss of Composites After Three Different Finishing and Polishing Techniques: An In Vitro Study.

IntroductionThe purpose of this in vitro study was to evaluate the effect of three different polishing systems on the microhardness, surface roughness, and gloss of resin composites.Materials and MethodsThe materials evaluated were 3M™ ESPE™ Filtek™ Z-350 XT (3M™, St. Paul, MN, USA), Grandio (Voco, Cuxhaven, Germany), 3M™ ESPE™ Filtek™ Z250 (3M™, St. Paul, MN, USA), Shofu-Beautifil Flow (Shofu, Kyoto, Japan), and RestoFill HV N-FLO (Anabond Stedman, Chennai, India). A total of 450 samples were fabricated. Three finishing and polishing systems: PoGo® (Dentsply Caulk, Milford, DE, USA), Sof-Lex Spiral, and Sof-Lex Pop-On (3M™, St Paul, MN, USA) were evaluated. Hardness, roughness, and gloss were evaluated after finishing and polishing. The surface roughness was measured with a surface profilometer, microhardness was measured with the Struers Duramin-5 microhardness tester (Struers A/S, Ballerup, Denmark) and gloss was measured using a gloss meter. The measurement values were analysed by Kolmogorov-Smirnov, Shapiro-Wilks test, and two-way ANOVA.ResultsThe Sof-Lex Spiral group exhibited higher mean microhardness (p < 0.001), less surface roughness (p < 0.001), and higher gloss (p < 0.001). Filtek Z-250 exhibited higher mean microhardness (p < 0.001) than Grandio (p < 0.001) and Shofu Beautifil Flow (p < 0.001), and Filtek Z-350 XT exhibited more microhardness than Shofu Beautifil Flow (p < 0.001). Filtek Z-350 XT exhibited lower mean surface roughness than Filtek Z-250 (p < 0.05). Filtek Z-250 polished with Sof-Lex Spiral proved to have higher gloss (34.89 gloss units (GU)) than Grandio and RestoFill HV N-FLO (p < 0.05).ConclusionsHardest, smoothest, and glossiest surfaces were obtained with the Sof-Lex Spiral finishing/polishing system. The mean microhardness of Filtek Z-250 and Filtek Z-350 XT was found to be higher than other composites used in this study. Filtek Z-350 showed a lower mean surface roughness and Filtek Z-250 exhibited a higher mean gloss.

Investigation of hole quality in drilled Ti/CFRP/Ti laminates using CO2 laser

The machinability of titanium (Ti) and carbon fiber reinforced plastic (CFRP) (Ti/CFRP/Ti) laminates using CO2 laser is presented in this work. The effect of line energy and laser frequency on output responses such as heat affected zone (HAZ), taper angle (TA), metal composite interface (MCI) damage, surface roughness, dross height, and circularity were investigated. Line energy - the most influential parameter - demonstrated a threshold behavior; no drilling was observed below a certain line energy. Scanning acoustic microscopy (SAM), scanning electron microscopy (SEM), micro-computed tomography (μ-CT), and other imaging techniques were used to establish a correlation between laser parameters and CO2 laser machined damage in Ti/CFRP/Ti laminates. The results show that using a higher frequency and lower line energy can significantly improve the hole quality. However, dross free holes with minimum taper can be obtained using higher line energy.

An Investigation on Anti-Corrosion Properties of Electroplated Copper-Graphene Nano-Composite Films

In this report, graphene sheets used as reinforcements for improvement of anti-corrosion properties have been synthesized by electrochemical intercalation and exfoliation process. The (001) and (002) plane of graphene sheets at a 2θ angle of 13.2 and 26.13 confirmed by X-ray diffraction pattern. High-resolution TEM confirms 8-12 layers of graphene present in the final products. The as-received graphene sheets have been used as reinforcement with copper matrix to synthesize Cu-Gr nanocomposite by electrodeposition method. The results and investigations of Cu-Gr composite thin films deposited from the bath containing 0.1g/L and 0.5g/L graphene concentrations with acidic copper sulfate solution have been compared. The surface morphology and roughness of composites were studied by SEM, AFM and surface profiler. The presence of graphene in Cu-Gr nanocomposite confirmed by EDS analysis. It was observed that the reinforcement particle has increased the mechanical properties of Cu-Gr composite (by 30%) with the addition to the copper matrix. The corrosion resistance of sample was studied by Tafel extrapolation method in standard borate buffer solution. For nanocomposites of 0.5g/L graphene, the values of Tafel constants are, βa=177.37 mv, βc=138.51 mv, Icorr = 9.3165×10-7Amp/cm2, Ecorr = -0.051 volts and corrosion rate 0.01028 mm/a as comparison to the corrosion rate of pure electroplated copper of a value of 0.029 mm/a. The corrosion rate of 0.5g/L Cu-Gr composite was found to be decreased by 2.7 times as compared to pure copper thin films. The structure of the films before and after corrosion was also analyzed to co-relate the electrochemical and structural relationship.

Comparative evaluation of the depth of cure and surface roughness of bulk-fill composites: An in vitro study.

Composites are in great demand due to the esthetic needs of the patients, which explains a wide variation in the types of available composites. However, the mechanical strength of the materials is questionable. Therefore, the mechanical properties of the newly available bulk-fill composites have been tested. The main objective of the study was to compare the depth of cure (DOC) and surface roughness of 3 different bulk-fill composites: X-tra fil® (XTF), Tetric EvoCeram® Bulk Fill (TEC) and Beautifil® Bulk Restorative (BBR). Fifty-seven (n = 19 in each group) samples were made using brass molds. All samples were subjected to Vickers hardness testing and profilometry. The one-way analysis of variance (ANOVA) test was used for the data analysis, followed by Tukey's post hoc test. The differences in the mean surface microhardness values of the materials were statistically significant (p < 0.001), with XTF showing the highest value. The TEC composite showed a higher surface roughness as compared to BBR and XTF. The results of the present study indicate that variations in the filler size and amount significantly influence the DOC and surface roughness of dental composites. Among the tested composites, the multi-hybrid composite exhibited superior DOC (XTF), whereas the nanohybrid composite exhibited superior surface finish (TEC).

Screw withdrawal resistance and surface roughness of woven carbon and glass fiber-reinforced wood-plastic composites

Wood-plastic composites (WPCs) have become one of the most remarkable materials for construction in recent years. Along with high resistance against biological threats, the high mechanical properties are also desired from WPCs as well. In this study, polypropylene (PP) and polyethylene (HDPE) based flat-pressed WPC specimens were reinforced with woven fiber fabric to gain higher mechanical properties. Woven fabrics were located 20% (w/w) below for both surfaces. Carbon fiber and glass fiber woven fabrics, known to have high mechanical properties, were preferred to improve screw withdrawal resistance (SWR) of WPC. Specimens were produced with different wood flour contents (40, 50, and 60%). Results indicated that the increase of SWR reached up to 83%. The highest increase was obtained from carbon fiber for PP, while it was glass fiber for HDPE fabric. The coupling agents had a positive effect on SWR. This study also showed that PE based WPCs had higher SWR compared to PP based ones. Moreover, as wood flour content increased, SWR decreased. The surface roughness of WPCs was also investigated. Contrary to SWR, the wood flour content positively affected the surface roughness; i.e., as wood content increased, surface roughness of WPCs increased. The structure of specimens were also examined using SEM.

Characterization of Lubricated Friction Behavior of Thermal Spray Steel Coatings in Comparison with Grey Cast Iron

This work examines friction properties of smooth-honed thermal spray (TS) low carbon steel coatings produced on an Al-9.0% Si alloy using a plasma transferred wire arc (PTWA) method and an AISI 1010 wire used as feedstock in comparison with the ASM type D grey cast iron (CI) samples subjected to the same (smooth) honing process. CI samples prepared using a standard honing process were also tested for comparison. Reciprocating sliding tests were performed using a Cameron–Plint tribometer against CrN-coated counterfaces within a speed range of 0.06–1.20 m/s covering the boundary and mixed lubrication conditions. Stribeck curves were constructed to show the coefficient of friction (COF) variations with the ratio (λ) of lubricant film thickness to composite surface roughness of TS and CI samples at the mid-stroke position where sliding speeds and surface roughnesses were measured. Examination of the Stribeck curves showed that the TS coated surfaces provided lower COF values compared to CI surfaces given the same smooth honing treatment, e.g., for λ = 2.7 a COF of 0.029 was observed for TS and 0.035 for CI, whereas conventional honing of CI provided a COF of 0.047 under the same condition. Metallographic evidence was given for the surface features and formation of tribolayers on the contact surfaces. The arithmetic mean heights of the surfaces, Sa measured after the tests remained similar for the smooth-honed TS and CI samples. The low COF values of the TS samples were discussed in terms of the surface pores generated during their manufacturing process, and the high oil retention depth ratio (Svk/Sk) of the TS coated surfaces due to the presence of these pores.

Is Deterioration of Surface Properties of Resin Composites Affected by Filler Size?

Purpose To investigate the effect of filler size on surface gloss and roughness of resin composites using a glossmeter and 3D noncontact surface topography, respectively, before and after tooth-brushing abrasion. Materials and Methods Seven model resin composites and one commercial were tested in the study. All materials were first polished, and then the surface gloss and 2D and 3D roughness parameters were recorded. Materials are then subjected to abrasion in a tooth-brushing simulator. Roughness parameters were recorded after 10,000 cycles, and after 20,000 cycles, both roughness and gloss were recorded. One-way ANOVA and Bonferroni post hoc test (p < 0.05) were used to analyze data. Conclusion Filler size is strongly correlated to gloss and surface roughness retention.

Effect of shot peening on surface properties of Al7075 hybrid aluminum metal matrix composites

Various fields of engineering such as automobile, aerospace and construction industries are employs Aluminum alloys and its composites due to its high strength to weight ratio. But they possess poor wear resistance due to low hardness. In this research, shot peening treatment is used to enhance the wear resistance ability of the composites. Micro hardness and surface roughness of AL7075 Hybrid metal matrix composites are examined after shot peening treatment. For this, the aluminum alloy specimens are subjected to shot peening for 30, 60, 90, 120 and 150 s time. The results reveal that the shot peening treatment increases micro -hardness and surface roughness up to 90 s. The specimen after 120 s peening demonstrates the marginal improvement in micro hardness and slight reduction in surface roughness.