ANALISIS PERBANDINGAN SIFAT MEKANIS PIPA TEMBAGA AC BARU DAN BEKAS

Abstract

In the repair of the installation of air conditioners or refegeration are often
found referigeran (ACR) tube that must be replaced because the old copper tube
leaked on the connection. Replacement is done because the repair of the connection
by cutting and flaring the connection usually fails in the form of a tear on the flared
part.The cause of flaring failure in the used air conditioner tube by testing the
mechanical properties and the microstructure of the material and compared with the
mechanical properties and the microstructure of the new tube material.Knowing the
causes of the failure can be searched for the prevention and repair solutions so that
the old tube can be used without replacement.
The tensile test results showed that the average ultimate strength of the used
ACR copper tube has increase in strength of 18188.65 N/mm2 comparing with the
ultimate strength of the new copper tube which was only 14615.15 N/mm2.The micro
Vickers test results show the same phenomenon from the tensile test results, where
the hardness value of used ACR tube has 42.7 HV while the new ACR tube is 37.8
HV.Microstructure testing with SEM shows the changing in grain structure from a
longitudinal shape with a large enough grain size and tenuous in a new tube, to more
flat and dense longitudinal grain structure for used tube.