PENGUKURAN PENGARUH TEKANAN PERAH PADA TEGANGAN SISA PADUAN AlSi SQUEEZE CASTING DENGAN TEKNIK DIFRAKSI SINAR-X[Measurements of Pressure Die Effects on The Residual Stresses of Squeeze Casting AlSi Alloys using X-Ray Diffraction Techniques]

Abstract

PENGUKURAN PENGARUH TEKANAN PERAH PADA TEGANGAN SISA PADUAN AlSi SQUEEZE
CASTING DENGAN TEKNIK DIFRAKSI SINAR-X.Telah dilakukan pengukuran tegangan sisa bahan
paduan AlSi hasil pengecoran cara perah (squeeze). Tegangan sisa yang diukur dalam daerah intergranular
disekitar batas butiran dengan metode difraksi sinar-X. Tailoring teknik difraksi-metode Rietveld mampu
mendapatkan parameter regangan kisi rata-rata dan full width half maximum (FWHM) setiap fasa dalam paduan.
Grafik memperlihatkan bahwa fasa aluminium mengalami tegangan compressive-tensile sedang fasa silikon
mengalami total tegangan compressive. Dominasi komposisi unsur aluminium mengakibatkan pola distribusi
tegangan sisa dalam paduan AlSi mengikuti pola tegangan sisa dalam fasa aluminium, meskipun peregangan kisi
didominasi fasa silikon yang mengalami regangan negatif. Hasil penelitian memperlihatkan, kurva tegangan sisa
dalam bahan paduan AlSi berfluktuasi antara -800 GPa hingga 400 GPa.

Abstract

The measurements of residual stresses on squeeze casting AlSi alloys has been carried out. The residual
stresses were measured in the inter-granular areas around the grain boundaries of the phases by using X-ray
diffraction techniques. The tailoring of diffraction method and Rietveld analysis could be applied to calculate
the average lattice strains of the phases and the profile parameters (FWHM) in the specimens. The graph
shows that the aluminium phase was in compressive-tensile stresses while the silicon phase was in totally
compressive stresses. The domination of aluminium composition in the specimens tends to affect the residual
stress behaviour of the squeeze casting AlSi alloys. The stress distribution of the alloys follows the profile of
stress curve of aluminium phase, even-though the strains were dominated by silicon phase in negative strains.
The result shows that the hydrostatic residual stresses curve of squeeze casting AlSi alloys fluctuates between
approxiamately -800GPa and 400 GPa.