Ayu Rizeki Ridhowati, Eka Febriyanti, Rini Riastuti


Warm rolling is one of the thermomechanical method has several advantages such as produces high mechanical properties, but does not decrease % elongation and toughness value because partial recrystallization phenomenon that produces micron-sized new grain. This paper reports the results of an investigation carried out on the effects of holding time annealing to mechanical properties Cu-Zn 70/30 alloy. These alloy after homogenization process and quenched in the air then heated to temperature of 300°C, later the heated copper samples are warm rolled at 25%, 30%, and 35% reduction, after that heated at temperature 300°C and held during 120 minutes. Then sample is experienced rewarm rolling with reduction 25%, 30%, and 35%. The results obtained showed that the ultimate tensile strength and yield strength are higher proportional with the increasing of % reduction, their values are 501,1 MPa; 599,3 MPa; later decrease to 546, 5 MPa and to yield strength are 441,8 MPa; 466,1 MPa; then decrease to 458,6 MPa. Moreover hardness value increase proportional with % reduction such as 154 HV; 162 HV; after that decrease to 160 HV While, % elongation decreases inversely proportional with % reduction namely 12,4%; 8,2%; later increase to 11,2 %. It is caused of the partial recrystallization phenomenon as evidenced by the presence micron-sized.


Warm rolling merupakan salah satu metode termomekanik yang mempunyai beberapa keuntungan yaitu salah satunya menghasilkan sifat mekanik yang tinggi, namun tidak mengurunkan nilai keuletan karena adanya fenomena rekristalisasi parsial yang menghasilkan butiran baru berbentuk micron. Paper ini menjelaskan tentang hasil penelitian berupa pengaruh persentase reduksi terhadap sifat mekanis paduan Cu-Zn 70/30. Paduan Cu-Zn 70/30 setelah dilakukan proses homogenisasi dan didinginkan di udara lalu dipanaskan ke suhu 300°C, kemudian masing-masing dilakukan warm rolling dengan persentase reduksi sebesar 25%, 30%, dan 35% kemudian ditahan di suhu 300°C dalam waktu 120 menit. Selanjutnya sampel dilakukan rewarm rolling dengan persentase reduksi sebesar 25%, 30%, dan 35%. Hasil penelitian yang dilakukan antara lain nilai kekuatan tarik (UTS dan YS) yang semakin tinggi sebanding dengan peningkatan % reduksi warm rolling yaitu masing-masing untuk nilai UTS sebesar 501,1 MPa; 599,3 MPa; lalu menurun menjadi 546,5 MPa serta untuk nilai kekuatan luluh sebesar 441,8 MPa; 466,1 MPa; lalu menurun menjadi 458,6 MPa. Selain itu, nilai kekerasan meningkat sebanding dengan peningkatan % reduksi warm rolling masing-masing sebesar 154 HV; 162 HV; lalu menurun menjadi 160 HV. Sedangkan persentase elongasi semakin menurun berbanding terbalik dengan peningkatan % reduksi masing-masing sebesar 12,4%; 8,2%; lalu meningkat menjadi 11,2%. Hal tersebut disebabkan karena adanya fenomena rekristalisasi parsial yang dibuktikan dengan kehadiran butir kecil berukuran mikron.

Keywords : Cu-Zn 70/30 alloy, warm rolling, anneal, % reduction, mechanical properties

Full Text:



William D.Callister Jr., An Introduction : Material Science and Engineering, John Wiley & Son, Inc., 2007, hal.373

Nestorovic, S. and Tancic, D., “Anneal Strengthening Effect in Sintered Copper-Based Alloys”. International Conference on Deformation and Fracture in Structural PM Materials, Slovaki,. (2002), hal.144 – 15

Kouzeli, M. and Mortensen, A.,“Size Dependent Strengthening in Practice Reinforced Aluminum”, Acta Metallurgical., 50 (2002), hal.39 – 51.

Majta, J., Stefanska-Kqdziela, M. and Muszka, K., “Modeling of Strain Rate Effects on Microstructure Evolution and Mechanical Properties of HSLA and IF- Ti Steels”, The 5th International Conference on HSLA Steels, 8 – 10 November, 2005. Sanya, Hainan, China, (2005) hal. 513 – 517.

Hust, J.G. and Lankford, A.B., “Thermal Conductivity of Aluminum, Copper, Iron and Tungsten for Suhues from 1 K to the Melting Point”, National Bureau of Standards: Boulder, CO. NBSIR 84- 3007, (1984)

Nestorovic, S., “Influence of Deformation Degree at Cold-Rolling on the Anneal Hardening Effect in Sintered Copper-Based Alloys”, Journal of Mining and Metallurgy, vol. 40, issue 1, (2004), hal. 101 – 10

Eka Febriyanti, Pengaruh Suhu Warm rolling dan Derajat Deformasi terhadap Sifat Mekanis dan Morfologi Struktur Paduan Cu-Zn 70/30, Tesis, (2015)

Nestrovic, S., “Influence of Time Annealing on Anneal Hardening Effect of A Cast Cu-Zn Alloy”, Journal of Mining and Metallurgy, vol. 39, issue (3-4)B, (2003), hal.489-497

ASTM E8, 2003, “Standard Test

Methods for Tension Testing of Metallic


ASTM E3-01, 2003, “Standard Guide

for Preparation for Metallographic


ASTM E92, 2003, ”Standard Test

Methods for Vickers Hardness of

Metallic Materials”

Krishna Chenna, S.,,“On the

Prediction of Strength from Hardness for Copper Alloys”, Journal of Materials, (2013), article ID 352578, Hindawi Publishing Corporation, hal.1-6

L.J Radovic, “The Influence of Thermomechanical Treatment on Recrystallization of Al Mg4,5Cu0,5 Alloy”, Metallurgija Journal of Metallurgy, Review Paper AMES, hal.83-88.

N.K Tewary, S.K Ghosh,and S. Chtterjee, “Effect of Annealing on Microstructure and Mechanical Behaviour of Cold Rolled Low C, High Mn TWIP Steel, International Journal of Metallurgical Engineering, (2015), vol. 4, issue 1, hal. 12-23

G. Dini, A. Najafizadeh, S. M. Monir- Vaghefi and R. Ueji, “Grain Size Effect on the Martensite Formation in a High- Manganese TWIP Steel by the Rietveld Method”, J. Mater. Sci. Technol, Vol. 26, (2010), hal. 181-186



  • There are currently no refbacks.