I do not think if you need to polish the sample to achieve to a mirror finish. As you can see, it is enough that the samples have no clear surface defects. in most cases the test can be carried out on the fabricated samples without any special preparation.

For tensile test; mirror finish may not be required; pl check ASTM standard reference for tensile testing if MMC.

Thanks Mr. seyed, Mr. Gunaban and Mr. Maharshi for you suggestions.

Can you please tell me how to give mirror finish for Aluminum reinforced MMC for microstructure studies.

do a regular metallographic specimen preparation; finally do a diamond paste based lapping for mirror polishing

For carrying out tensile test, mirror finishing is not necessary, however good surface finish on the test specimen is must.

Thank you

Denten Zangpo

Polishing of composite tensile specimens is unnecessary. Usual metallographic procedure can be applied to polish MMC specimens for microstructural observation. However, a mirror finish is not always obtained compared to unreinforced monolithic matrix. Because, the metallic matrix material undergoes erosion during polishing. But, the reinforcement particles remain almost unaffected during polishing and etching. Therefore, a fine polished metal matrix composite specimen will not look so bright especially if the reinforcement volume fraction is more than 10%.

To make tensile test, the mirror surface is not mandatory. but the tensile specimen profile smoothness is very important.

Dear Arunkumar K N

It is not necessary to obtain mirror finish for tensile test specimens. Moreover, all tensile test specimens should be subjected to testing, immediately after they are cast. Because, the secondary machining processes such as grinding leads to work hardening, leading into inaccuracy in the test results.

Mirror finish is not necessary for tensile test. Go for lapping process using diamond pads

Mirror finish or any type of polishing is not required for tensile testing of MMCs. However, to get an accurate value, one should follow the exact dimensions of the specimens as per ASTM standard. The specimen especially, the gauge length should not contain any porosity.