i used a certain waste product as friction material in automotive brake pads and linings.The mix has been made and the sample brake pads and linings produced already following standard.Testing using standard equipment is the difficulty i'm faced with now.I've been using what i have at hand and even constructing some emergency set up.
First how is the calculation of the percentage of swell and growht done?I got the tickness of the specimens before and after heating in an oven at 205 degree for one hour.Pls how do i go about getting the percentage of swell and growth of specimens?
Second,the thermal mechanical analysis. i got the dimensions as required from each specimen and will like to know which method is best suited for the anylsis of data and the reference standard.
Third,the test of static coefficient of friction.i used a solide flat surface made of mild steel on which my sample was allowed to slide and the angle taken.The problem i had here was that as the load was applied, the variation of angle did not follow an expected patern i.e if for a load of 500g the angle was 20 degree, it happens that for a load of 1000g the angle was 18 degree while for a load of 1500g the angle could be 21 degree.I don't understand that fluctuation in the angle variation.Is it due to error as all this process is carried out manualy or is that the equipment is not appropriate for such tests?