Jixie qiangdu (Jan 2022)
EFFECT OF STATIC PRESSURE ON SURFACE INTEGRITY OF BERYLLIUM COPPER ALLOY TREATED BY ULTRASONIC ROLLING
Abstract
To study the effect of static pressure on the surface integrity of beryllium copper alloy during the ultrasonic rolling process, scanning electron microscope, stylus roughness tester, rockwell hardness tester, X-ray diffraction analyzer and metallographic microscope were used to measure and analyze the surface morphology, roughness, surface hardness, residual stress and microstructure of the before and after ultrasonic rolling specimens. The results indicate that the static pressure and the surface roughness show a nonlinear relationship in the range of test parameters. With the increase of static pressure, the surface roughness decreases first and then increases. Moreover, we can obtain better surface quality when the static pressure is 0.2 MPa～0.4 MPa. Work hardening and grain refinement of the material surface caused by the plastic strain generated during the ultrasonic rolling process are the main reasons for the increase in hardness. The surface hardness of the treated specimen can reach 43.3 HRC, which is 18.6% higher than that of the untreated specimen.The ultrasonic rolling treatment can transform the residual tensile stress on the surface of the material into residual compressive stress, which is of great significance for improving the surface mechanical properties of the material.
