Analisis Intensitas Dan Coverage Proses Shot Peening Terhadap Tegangan Sisa Dan Kekerasan Paduan Al 7075 T7351

Abstract

AbstrakShot peening merupakan metode pengerjaan dingin dengan menumbukkan permukaan logam menggunakan partikel-partikel bulat yang berukuran kecil dan berkecepatan tinggi. Dengan proses shot peening dapat dikurangi inisiasi dan propagasi retak yang menyebabkan terjadinya kegagalan terhadap logam. Tujuan penelitian ini adalah untuk mengetahui pengaruh intensitas dan coverage shot peening terhadap tegangan sisa dan kekerasan pada permukaan Al 7075 T7351. Penelitian dilaksanakan dengan menembakkan permukaan logam dengan intensitas 0,0062 A dan 0,0091 A, serta coverage masing-masing 100% dan 200%, kemudian dilakukan pengujian kekerasan permukaan dan tegangan sisa. Hasil penelitian menunjukkan bahwa shot peening menyebabkan terjadinya perubahan tegangan sisa, yaitu 92,5021 MPa pada keadaan tanpa shot peening menjadi -111,8726 sampai -170,5675 MPa setelah dilakukan dishot peening. Selain itu kekerasan pada permukaan meningkat antara 23,4% sampai dengan 44,7%. Meningkatnya kekerasan menunjukkan bahwa terjadi pengerjaan dingin yang besar pada permukaan logam. Pengaruh pelapisan (coverage) 200% ternyata meningkatkan besarnya tegangan sisa dan kekerasan permukaan walaupun belum melampaui intensitas yang lebih besar. Kata kunci : shot peening, intensitas, coverage, kekerasan permukaan, tegangan sisa AbstractShot peening is a cold working method by striking metal surfaces using small, high-speed and round particles. Shot peening can reduce the initiation and propagation of cracks that cause metal failure. The purpose of this analysis is to determine the effect of shot peening intensity and coverage on residual stress and hardness on the surface of Al 7075 T7351. The research was carried out by firing metal surfaces with intensities of 0.0062 A and 0.0091 A, and coverage of 100% and 200%, respectively, then testing surface hardness and residual stress. The results showed that shot peening caused a residual stress change, which was 92.5021 MPa in the state without shot peening to -111.8726 to -170.5675 MPa after it was shot peening. In addition, surface hardness increased from 23.4% to 44.7%. Increased hardness indicates that there is large cold working on the metal surface. The effect of 200% coverage apparently increases the amount of residual stress and surface hardness even though it has not exceeded the greater intensity. Keywords: shot peening, intensity, coverage, surface hardness, residual stress

Analysis of the Effect of Time on Tensile Strength and Hardness of Electroplating Method Using Nickel on Aluminum 7075

“…The use of aluminum material in the aircraft industry is profoundly common. Aluminum alloy 7075 series is frequently used in this industry for its strength, corrosion resistance, damage tolerance, and lightweight [7].…”