[1]PTNBR-BA TAN Jl. Tamansari 71 Bandung 40132 Indonesia;
[2]Metallurgy Engineering Bandung lnstitut of Technology Jl. Ganesa 10 Bandung 40132 Indonesia;
[3]Materials Engineering Bandung Institut of Technology Jl. Ganesa 10 Bandung 40132 Indonesia;