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In this paper, the theoretical models of the surface topography and residual stress (RS) were proposed, and the abrasive water jet sequential peening (AWJSP) finite element models were established by using ABAQUS. Then, the formation mechanism of the surface topography in multiple passes AWJSP process and the coupling mechanism of RS in a single and multiple passes AWJSP process were analyzed. After that, the influence of the number of shots (i.e. N), the distance between the center of adjacent shots Dc, shot velocity v, and shot radius R on the surface topography and residual stress field (RSF) of the target were investigated. Results show that successive dimples were formed by single-pass AWJSP, the RSF formed by the impact of each shot will influence the previous RSF, and that will be coupled with it. In multiple passes AWJSP process, decreasing Dc can decrease the surface roughness, the surface smoothness of the target material will gradually become better, and the RSF will also be uniform. Under full coverage condition, the surface roughness Rt and mean width of the profile Rsm will gradually decrease with the decrease of Dc, while the change of Dc has little influence on the RSF. Increasing the v can increase Rt and Rsm, and it is beneficial to induce a large and deep compressive RS layer. Increasing the R can decrease Rt, Rsm remains unchanged, and it is beneficial to induce a deep compressive RS layer. [ABSTRACT FROM AUTHOR]

A new method for fabricating CCMPMPs, namely multi-cutter milling, is proposed and the fabrication principle is discussed. Then, a study of three microchannel parameters, the microchannel depthHc, widthWc, and intervalWs, and two CCMPMP parameters, the porosityPand the total surface area per unit volumeSV, is presented. Furthermore, 3D FEM has been adopted to study the effective stress distribution, the metal flow velocity distribution, and the cutting forces. The results show that CCMPMPs can be successfully machined.Hc,Wc, andWscan be controlled by the radial depth of cutae, the slotting cutter thicknessEt, and the gasket thicknessEg, whilePandSVcan be changed by adjustingHc,Wc, andWs. Moreover, asaeincreases, the average resultant force increases, and the friction between chip and the side face of the machined microchannel, and between chip and the rake face, plays an increasingly important role in it. [ABSTRACT FROM PUBLISHER]

The water jet peening (WJP) technology can induce compressive residual stress (RS) in metal surfaces and, thus, improve the fatigue life of components. In this paper, a mathematical model is proposed for calculating the RS induced by WJP. To validate the proposed mathematical model, experimental and finite element simulation verifications were carried out on Al6061-T6. The distribution of RS along the depth direction, the maximum compressive RS, and the depth of the compressive RS layer were also investigated based on the mathematical model. Results showed that the error of maximum compressive RS between the mathematical model and experiment was within 9% under a jet pressure of 60 MPa, and the error of depth of the compressive RS layer between the mathematical model and experiment was within 13% under a jet diameter of 0.3 mm. Hence, the mathematical model is reliable and accurate. The maximum compressive RS increases with the increase in jet pressure, and the depth of the compressive RS layer approximately linearly increases with the increase in jet diameter. [ABSTRACT FROM AUTHOR]