Corrosion Rate of Black Chromium Coating Result of Electroplating on Copper

The problem faced is that the white chromium coating has a low selling value or aesthetic value than the black chromium layer which is more in demand, especially by the younger generation who prioritizes aesthetics. The purpose of the corrosion test was to determine the corrosion resistance ability of the black chromium coating resulting from the electroplating process on the relationship between the solution temperature and the immersion time of copper in a corrosive solution. Corrosion test methods include literature studies, field observations, weighing specimens, immersing specimens in corrosive solutions, weighing specimens, calculating corrosion rates, and data analyzing. Corrosion test results show that the higher the temperature of the solution and the longer the immersion time, the smaller the corrosion rate for the lowest conditions at 30oC and a duration of 5 minutes with a corrosion rate of 0.2004 mm/year and the highest conditions at a temperature of 50oC and a duration of 9 minutes at a rate of corrosion of 0.0108 mm/year

Pengaruh Kadar Tembaga Dan Radius Spesimen Uji Lelah Standar Terhadap Umur Lelah Sudu Propeler

Permasalahan yang dihadapi pada poros propeler adalah belum diketahui untuk prediksi penggantian dalam perawatan akibat perbedaan pengaruh jenis bahan dan radius spesimen uji lelah batang putar terhadap hasil umur lelah. Tujuan penelitian untuk mengetahui perbedaan umur lelah akibat perbedaan jenis bahan dan radius spesimen uji lelahnya. Metode penelitian adalah experimental dengan menguji lelah 2 kadar tembaga dan ukuran radius spesimen pada 210 mm dan 220 mm dengan jumlah spesimen 44 buah. Radius spesimen 210 mm dengan diameter minimal spesimen 7,3 mm menunjukkan umur lelah tertinggi pada kuningan C1100 pada radius 210 mm senilai siklus N= 1701555 putaran pada S= 224 MPa, dan umur lelah terendah senilai N= 258480 putaran pada S= 373 MPa, sedangkan pada radius 220 mm menunjukkan umur lelah tertinggi senilai siklus N= 8746950 putaran pada S= 224 MPa, dan umur lelah terendah senilai N= 627420 putaran pada S= 373 MPa. Sedangkan pada spesimen kuningan C3604BD pada radius 210 mm menunjukkan umur lelah tertinggi senilai siklus N= 1550355 putaran pada S= 224 MPa, dan umur lelah terendah senilai N= 125130 putaran pada S=373 MPa, sedangkan pada radius 220 mm menunjukkan umur lelah tertinggi senilai siklus N= 2370000 putaran pada S= 224 MPa, dan umur lelah terendah senilai N= 372350 putaran pada S= 373 MPa, dengan demikian secara keseluruhan perbedaan umur lelah kuningan C1100 lebih lambat sekitar 76,6% dibandingkan dengan kuningan C3604BD yang lebih cepat sekitar 47,6%

Corrosion Rate of Black Chromium Coating Result of Electroplating on Copper

The problem faced is that the white chromium coating has a low selling value or aesthetic value than the black chromium layer which is more in demand, especially by the younger generation who prioritizes aesthetics. The purpose of the corrosion test was to determine the corrosion resistance ability of the black chromium coating resulting from the electroplating process on the relationship between the solution temperature and the immersion time of copper in a corrosive solution. Corrosion test methods include literature studies, field observations, weighing specimens, immersing specimens in corrosive solutions, weighing specimens, calculating corrosion rates, and data analyzing. Corrosion test results show that the higher the temperature of the solution and the longer the immersion time, the smaller the corrosion rate for the lowest conditions at 30oC and a duration of 5 minutes with a corrosion rate of 0.2004 mm/year and the highest conditions at a temperature of 50oC and a duration of 9 minutes at a rate of corrosion of 0.0108 mm/year.</jats:p

Effect of Material Type and Minimum Diameter of Specimens on the Fatigue Life

The obstacle faced during the fatigue test is the waiting time which is quite long and inefficient, especially for test specimens made of ductile metal with waiting times of up to several days. The research method includes reducing the specimen radius to obtain a flexural stress approaching 400 MPa which was originally 229 MPa from a radius of 254 mm to 240 mm with the results of turning the original specimen obtained a minimum diameter of 8.6 mm is reduced to 7.3 mm at a maximum loading of 10 kg. Results of the research are brass specimens C3604BD type with a minimum diameter of 8.6 mm at a flexural stress of 298 MPa showing a fatigue life of 2455546 cycles with a test duration of 1754 minutes and a minimum specimen diameter of 7.3 mm at a flexural stress of 299 MPa showing a fatigue life of 684311 cycles with a test duration of 489 minutes which means that with a minimum specimen diameter of 7.3 mm the fatigue life is 3.59 times shorter than a minimum specimen diameter of 8.6 mm. Meanwhile, for aluminium AA1101 type with a minimum specimen diameter of 7.3 mm at a flexural stress of 182 MPa, the fatigue life is 422117 cycles with a test duration of 278 minutes and with a minimum specimen diameter of 8.6 mm at a flexural stress of 183 MPa, the fatigue life is 389232 cycles with a test duration of 302 minutes which means that with a minimum specimen diameter of 7.3 mm the fatigue life is 1.05 times shorter than the minimum specimen diameter of 8.6 mm or almost the same.</jats:p