Resumen:
En
|
Texto:
En
|
PDF:
En
Aluminum Hybrid Metal Matrix Composites (Al-HMMCs) are contemporary materials that blend aluminum with additional reinforcing elements to enhance their mechanical, thermal, and other properties. These materials find applications across various sectors including the aerospace industry, automotive sector, military and defence, marine industry, as well as manufacturing industries. In this research, AA6061, zirconium dioxide (ZrO2) and boron carbide (B4C) have been selected as the matrix and reinforcement materials. AA6061/ZrO2/B4C (Al-HMMCs) is manufactured using Ultrasonic-assisted stir casting. The process parameters of ultrasonic assisted stir casting were optimized with the help of Taguchi optimization technique. The melting temperature (700, 750 and 800 ºC), stirring speed (10, 15 and 20 minutes) and AA6061/xwt.%B4C/xwt.%ZrO2 ( 6, 8 and 10) are selected as input parameters for optimization. The reinforcements ZrO2 and B4C are weighed by equally sharing by wt.% The micro hardness was selected as response parameter and it was determined by using Vickers micro hardness tester. The L9 Orthogonal Array (OA) was employed for optimization of input parameters of ultrasonic assisted stir casting. Taguchi results showed that medium level of melting temperature (750 ºC), higher level of stirring speed (300 rpm), lower level of stirring duration (10 minutes) and medium level of wt.% of ZrO2 and B4C (8wt.%) were the optimized combination of input process parameters of ultrasonic assisted stir casting for fabricating AA6061 HMMC. The AA6061/xwt.%B4C/xwt.%ZrO2 (x = 0,4,6,8 and 10) HMMCs were manufactured by utilizing optimized process parameters. The micro hardness of AA6061/xwt.%B4C/xwt.%ZrO2 (x = 0,4,6,8 and 10) was determined. . From the obtained hardness tests, it was observed that the hardness of AA6061 HMMCs was enhanced up to addition of 8wt. % of B4C and ZrO2 and decreased the hardness while adding 10wt.% of B4C and ZrO2. The better AA6061/8wt.%ZrO2/8wt.%B4C HMMC undergone X-ray Diffraction Analysis (XRD) and Scanning Electron Microscope (SEM) testing to identify elements and examine the microstructure. The high peak of ZrO2, B4C and Al was obtained in 71.4, 35.68 and 37.81 2 theta values respectively. The SEM image of ultrasonic aided stir cast AA6061 based composite was confirmed the uniform distribution of zirconium di oxide and boron carbide reinforcements. There was no oxide formation on the surface of the stir casted AA6061 composites due to the execution of casting process in the inert environment. The casted AA6061/8wt.%ZrO2/8wt.%B4C surface of the composite exhibits no porosity occurrence due to the impact of usage of ultrasonic vibrator to prevent the formation of holes due to escape of unwanted gases. Subsequently, corrosion tests were conducted on the AA6061 HMMC in various corrosive environments such as NaOH, HCl, H2SO4, and NaCl to evaluate its electrochemical behavior. The surfaces of corroded specimens were analyzed using SEM and Energy Dispersive Spectroscopy (EDS). The research findings indicate that AA6061 composites exhibit the highest corrosion resistance when immersed in a NaCl medium. This enhanced resistance was attributed to the medium's lower corrosion potential, stronger charge transfer resistance (Rct), and lower double-layer capacitance (Cdl) compared to alternative environments. Additionally, SEM analysis illustrated that the incorporation of B4C and ZrO2 ceramics results in the formation of protective barrier layers, further enhanced their corrosion resistance. ZrO2 particles were attracted and neutralized the corrosive ions and electrons, thereby reducing corrosive activity on the AA6061 aluminium matrix. AlHMMCs (Al-HMMCs mechanical thermal properties industry sector defence industries AA ZrO (ZrO2 BC B C (B4C AA6061ZrO2B4C AAZrOBC Ultrasonicassisted Ultrasonic technique 700, 700 (700 75 80 ºC, ºC , ºC) 10, 10 1 minutes AA6061xwtB4CxwtZrO2 AAxwtBCxwtZrO xwt AA6061/xwt.%B4C/xwt.%ZrO 6 wt wt. tester L OA (OA (75 300 (30 rpm, rpm rpm) (1 8wt.% 8wt (8wt.% AA606 x 0468 0 4 0,4,6, 10wt 10wt. AA60618wtZrO28wtB4C AAwtZrOwtBC Xray X ray XRD (XRD (SEM microstructure 714 71 71.4 3568 35 68 35.6 3781 37 81 37.8 respectively environment gases Subsequently NaOH HCl H2SO4 HSO H SO behavior EDS. EDS (EDS) mediums s potential Rct, Rct (Rct) doublelayer double layer Cdl (Cdl Additionally layers electrons (ZrO 70 (70 7 xwtB CxwtZrO AA6061xwtB4CxwtZrO (7 30 (3 (8wt. AA60 046 0,4,6 wtZrO wtB 71. 356 3 35. 378 37. H2SO (EDS (Rct (8wt AA6 04 0,4, 0,4 0,