J. Appl. Cryst.の発刊に際して

Influence of low-plasticity ball burnishing on the high-cycle fatigue strength of medium carbon AISI 1045 steel

Plasma electrolytic oxidation (PEO) coatings have been produced on aluminium substrates using a pulsed unipolar current mode at different duty cycle and frequency, along with reference samples produced using direct current. Residual stresses attributed to the α-Al 2 O 3 constituent of the coating have been evaluated by X-ray diffraction using the Sin 2 ψ method. It is found that compressive normal and shear stresses were present in the coatings, which indicated the existence of stress gradient across the coating thickness. Depending on treatment parameters, internal normal stress in the coatings ranges from − 111 (± 19) MPa to − 818 (± 47) MPa and shear stress ranges from − 45 (± 27) MPa to − 422 (± 24) MPa have been found. Correlations between internal stress and coating thickness, surface morphology and phase composition have been discussed. PEO regimes favourable for the production of coatings with minimal stress, dense morphology and relatively high content of α-Al 2 O 3 phase are recommended.

Residual stresses in plasma electrolytic oxidation coatings on Al alloy produced by pulsed unipolar current

Residual stresses and tetragonal phase fraction characterisation of corrosion tested Zircaloy-4 using energy dispersive synchrotron X-ray diffraction

This paper provides a state-of-the-art review on the investigations into the residual stresses in metallic structural materials generated by grinding. The materials covered include steels, titanium alloys, and nickel-based superalloys. The formation mechanisms of the residual stresses and their impacts are specifically discussed. Some major influential factors on the residual stresses formation in grinding, such as grinding wheel characteristics, dressing techniques, grinding parameters, cooling conditions, and properties of workpiece materials, are analyzed in detail. These include experimental measurement, modeling, simulation, knowledge-based monitoring, and fuzzy analysis. Finally, the paper highlights some important aspects of grinding-induced residual stresses for further investigation.

Review on grinding-induced residual stresses in metallic materials

Chromium–nickel steels are widely used in various fields of the engineering practice because of their increased corrosion resistance. One of the most used chromium–nickel steel is AISI 316Ti. It is known from the engineering practice that processing this steel by cutting creates difficulties and problems. However, there is no information regarding the effectiveness of the slide burnishing (SB) method in terms of quality of the processed surface of this chromium–nickel steel. A comprehensive experimental and FEM study of the surface integrity of slide burnished specimens made of AISI 316Ti austenitic stainless steel has been carried out. The effect of the SB parameters on the obtained roughness, microhardness, residual stress, fatigue strength (life) and wear resistance has been studied. A fully coupled thermal-stress FEM analysis has been conducted to be appreciated the effect of the generated temperature in SB process on the residual stress formation. The SB of AISI 316Ti steel achieves: roughness of Ra = 0.055 μm; micro-hardness increased by more than 32%; significant wear resistance; introduced residual stress with a maximum absolute value, which significantly exceeds the yield limit of the bulk material; increased fatigue strength by 38.9%; fatigue life increasing more than 385 times. The obtained experimental outcomes for the main characteristics of the surface integrity prove that SB can be successfully applied as a mixed burnishing for finishing symmetrical rotational components made of chromium–nickel steels.

Effect of slide burnishing method on the surface integrity of AISI 316Ti chromium–nickel steel

It is well known that apart from compressive residual stresses, smooth surface and microstructuring of the surface and subsurface layers are beneficial for enhancement of fatigue strength and load-carrying capacity of structural and machine components. This complex of properties can be achieved using surface severe plastic deformation. For symmetric rotational components made of high-strength aluminum alloys, slide burnishing is appropriate because of its simplicity and easy realization. The effect of the process parameters on the surface roughness, micro-hardness, and residual stresses obtained in slide burnishing of D16T aircraft aluminum alloy has been analyzed. The optimal values of the basic governing factors, which ensure minimum roughness (up to $$0.05\,\upmu\,{\text{m}}$$
 ), have been established on the basis of a one-factor-at-the-time method, followed by a planned experiment and additional experiments. With the established combination of optimal values, the effect of number of passes and lubricant-cooler on the roughness, micro-hardness, and residual stresses in the surface being treated has been studied for two working schemes. To establish residual stress–depth profiles depending on the tool radius and burnishing force, FEM analysis of the slide burnishing process has been conducted. Thus, an evaluation of the effectiveness of slide burnishing as “mixed burnishing” has been made.

Influence of the process parameters on the surface roughness, micro-hardness, and residual stresses in slide burnishing of high-strength aluminum alloys

The benefit from an adequate finite element simulation of the cold hole expansion process

Effect of slide burnishing basic parameters on fatigue performance of 2024‐Т3 high‐strength aluminium alloy

This paper presents a new method of mechanical surface treatment of external cylindrical surfaces and it is called “Spherical motion burnishing” (SMB). The axes of the workpiece and ring-shaped tool having toroidal acting surface intersect at angle θ =2°. The tool motion is superposition from a spherical motion and rectilinear translation with respect to the workpiece. The contact between the surface treated and its enveloped-tool acting surface is one of sliding friction in the presence of a lubricant. The method can be implemented on conventional machine tools, in particular on lathes by means of a relatively simple device and tool. To evaluate the manufacturing potentials of the SMB method a designed experiment has been carried out. The quality of the treated surfaces of workpieces made of low- and medium-carbon steel has been investigated experimentally. Mathematical models of the roughness and the residual axial normal stresses have been obtained on the basis of a planned experiment. The authenticity of the models has been proved on the basis of four extra tests. The method can be classified as mixed burnishing because it combines the advantages of hardening, dimensional burnishing and smoothing burnishing.

Nikolaj Ganev

Papers

Effect of slide burnishing method on the surface integrity of AISI 316Ti chromium–nickel steel

Influence of the process parameters on the surface roughness, micro-hardness, and residual stresses in slide burnishing of high-strength aluminum alloys

The benefit from an adequate finite element simulation of the cold hole expansion process

Effect of slide burnishing basic parameters on fatigue performance of 2024‐Т3 high‐strength aluminium alloy

Spherical motion burnishing implemented on lathes