The aim of this research paper is to find the wear behaviour of Al7075 MMCs. In this investigation, the wear tests on the as-cast and age-hardened specimens were performed on an advanced rotary tribometer. The materials selected for the analysis are Al7075 as a matrix, and the reinforcements are boron carbide. By using stir casting, metal matrix composites are manufactured by adding B4C as a reinforcement particulate in Al7075. The fabricated composites were characterized and the wear behaviour of these composites was carried out on an advanced rotary tribometer. The wt. % of the reinforcements was taken as 6%, 8%, 10%, and 12%. The almost homogeneous blending of reinforcements is shown by the microstructural characterization of Al7075 MMCs. It is observed that due to the rise in weight percentage of the reinforcement to 12% higher hardness is obtained. For 12% of reinforcements, there is an increase in hardness due to the heat treatment than that of the as-cast composites. From this study, it was found that the wear rate is the function of the applied load, microstructure, and volume fraction of the reinforcements. The wear rate was increasing with the sliding velocity.

In the new  millennium  and with  the  advent  of high  yielding  varieties of  paddy,  the  use  of various  pesticides,  some  of which  may  be in minute  quantities are  highly toxic  to  aquatic  life.  Fish  culture,  therefore,  is not  more  compatible with paddy  farming wherever the latest  high yielding  varieties of paddy  are cultivated. Champaran (Bihar) is known to be an area of high quality yielding rice  and are even  exported  to several countries. There  are numerous swampy and derelict lentic  water  bodies  in this  area.  In recent years.  however,  attempts are being made in the fish  culture to  utilize the vast swampy and  derelict water area  for immediate use  for  the  benefit  of the  poor,  without getting involved   in to  costly reclamation  process.  Despite  of  poor and  unorganized capture  fishery,  the  percent yield  was  estimated to be good. The fishes like Channa, Heteropneust, Anabus,  Clarius and even some  Carps  are being cultured in the paddy  fields  as well  as in the water  bodies  of this  area. By virtue of their  hardy  nature and air breathing habits in many cases,  they  are excellent  material  not only  for utilizing  swampy and  derelict water bodies but also  in paddy  fields as they  permit  high stocking  density  and respond to supplementary feeding.  Their  production potential is by and large  directly proportional to inputs  and intensity of operational management. Despite of good  inputs   of  these  commercial  fishes,   the  potential toxic   compounds in  various chemicals  used  for agricultural  and other  domestic purposes get  distributed by  a variety of  means  and  accumulate concentrations in the soil  and water.  These  accumulated organic  compounds lower the DO level and does  not support  fish  life.  Fish  species  are far from being biochemical  inert. As a matter  of facts several pesticides are known to induce   microsomal enzyme systems in the  liver  of fish.  Physiology,  biochemistry and pathology has enabled  us to  assess the  toxicity of the water body with  fish  and in these circumstances, fish can  be used  as an indicator of water quality.

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Due to the demand for lightweight materials in the field of automobiles, aeronautics and some other application, there is a need to develop lightweight materials. For the last few decades, aluminum matrix composites are being developed in order to meet out the demand of the above-mentioned industries. aluminum the above, lightweight material in the form of composites of B4C reinforced in Al7075 alloy is considered for the present investigation. The composite was produced using the stir casting method. In this investigation, the micro and nano B4C particles were used as reinforcements. The fabricated composites were characterized for microstructure and mechanical properties. From the microstructural examination, it was observed that 12% of B4C nanocomposites was having fine microstructure as compared to others. The hardness and strength were found to be maximum for 12 % B4C nanocomposites which impact strength was lowest for 12% micro composites.

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