Processing conditions affecting residual stresses and fatigue properties of cold spray deposits

2015 ◽  
Vol 81 (9-12) ◽  
pp. 1857-1862 ◽  
Author(s):  
P. Cavaliere ◽  
A. Silvello
Keyword(s):  
Residual Stresses ◽  
Cold Spray ◽  
Fatigue Properties ◽  
Processing Conditions

Crystal Plasticity Modeling of Laser Peening Effects on Tensile and High Cycle Fatigue Properties of 2024-T351 Aluminum Alloy

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Maziar Toursangsaraki ◽  
Huamiao Wang ◽  
Yongxiang Hu ◽  
Dhandapanik Karthik
Keyword(s):  
Residual Stresses ◽  
Crystal Plasticity ◽  
High Cycle Fatigue ◽  
Driving Forces ◽  
Crack Nucleation ◽  
Fatigue Properties ◽  
Laser Peening ◽  
Cycle Fatigue ◽  
Fatigue Crack Nucleation ◽  
Near Surface

Abstract This study aims to model the effects of multiple laser peening (LP) on the mechanical properties of AA2024-T351 by including the material microstructure and residual stresses using the crystal plasticity finite element method (CPFEM). In this approach, the LP-induced compressive residual stress distribution is modeled through the insertion of the Eigenstrains as a function of depth, which is calibrated by the X-ray measured residual stresses. The simulated enhancement in the tensile properties after LP, caused by the formation of a near-surface work-hardened layer, fits the experimentally obtained tensile curves. The model calculated fatigue indicator parameters (FIPs) under the following cyclic loading application show a decrease in the near-surface driving forces for the crystal slip deformation after the insertion of the Eigenstrains. This leads to a higher high cycle fatigue (HCF) resistance and the possible transformation of sensitive locations for fatigue failure further to the depth after LP. Experimental observations on the enhancement in the HCF life, along with the relocation of fatigue crack nucleation sites further to the depth, reveal the improvement in the HCF properties due to the LP process and validate the numerical approach.

Response of Cold Sprayed Ti6Al4V Coatings to Solid Particle Erosion and Micro-Scratch Wear Processes

2018 ◽  
Vol 941 ◽  
pp. 1680-1685 ◽  
Author(s):  
Miguel Ángel Garrido ◽  
Paloma Sirvent ◽  
Daniel Elvira ◽  
Álvaro Rico ◽  
Claudio J. Múnez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Solid Particle ◽  
Cold Spray ◽  
Mechanical Response ◽  
Operating Time ◽  
Wear Behaviour ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Spray Technique

Ti6Al4V alloy is widely used for aeronautical components due to a special combination of high mechanical properties, low density and good corrosion resistance at high temperature. These components are usually damaged by particles impacts during their operating time. When the reliability of these components is compromised, they are replaced with the consequent cost of material and time. Spraying coatings on the damaged surface could reveal as an alternative process to repair these components, increasing their operating life. Traditionally, thermal spray processes are used to repair the aeronautical components. However, the coatings produced by these processes are characterized by high residual stresses, porosity and oxidation. The cold spray technique is revealed as a promising spraying alternative due to the characteristic low temperature of the process. Consequently, residual stresses, oxidation, crack formation, phase transformations and microstructural changes are minimized. In this work, a cold spray technique was used to generate Ti6Al4V coatings onto a bulk of the same material. Three different spraying conditions were studied: Ti6Al4V coatings sprayed at 800oC; Ti6Al4V coatings sprayed at 1100oC; and Ti6Al4V coatings sprayed at 1100oC with a subsequent heat treatment: The wear resistance of these coatings was investigated by solid particle erosion and micro-scratch tests. The wear behaviour was determined under several wear tests conditions. Additionally, instrumented indentation tests were carried out on the coatings to determine their mechanical response. The wear mechanisms of the coatings were identified and compared to their microstructure and mechanical properties.

Theoretical prediction of residual stresses induced by cold spray with experimental validation

2019 ◽  
Vol 15 (3) ◽  
pp. 599-616 ◽  
Author(s):  
Dibakor Boruah ◽  
Xiang Zhang ◽  
Matthew Doré
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Cold Spray ◽  
Residual Stress Distribution ◽  
Thermal Mismatch ◽  
Individual Layer ◽  
Content Type ◽  
Layer Height ◽  
Proposed Model

PurposeThe purpose of this paper is to develop a simple analytical model for predicting the through-thickness distribution of residual stresses in a cold spray (CS) deposit-substrate assembly.Design/methodology/approachLayer-by-layer build-up of residual stresses induced by both the peening dominant and thermal mismatch dominant CS processes, taking into account the force and moment equilibrium requirements. The proposed model has been validated with the neutron diffraction measurements, taken from the published literature for different combinations of deposit-substrate assemblies comprising Cu, Mg, Ti, Al and Al alloys.FindingsThrough a parametric study, the influence of geometrical variables (number of layers, substrate height and individual layer height) on the through-thickness residual stress distribution and magnitude are elucidated. Both the number of deposited layers and substrate height affect residual stress magnitude, whereas the individual layer height has little effect. A good agreement has been achieved between the experimentally measured stress distributions and predictions by the proposed model.Originality/valueThe proposed model provides a more thorough explanation of residual stress development mechanisms by the CS process along with mathematical representation. Comparing to existing analytical and finite element methods, it provides a quicker estimation of the residual stress distribution and magnitude. This paper provides comparisons and contrast of the two different residual stress mechanisms: the peening dominant and the thermal mismatch dominant. The proposed model allows parametric studies of geometric variables, and can potentially contribute to CS process optimisation aiming at residual stress control.

Investigation of Residual Stresses in a Sleeve Coldworked Lug Specimen by Neutron and X-ray Diffraction

1994 ◽  
Vol 38 ◽  
pp. 455-461
Author(s):  
R. Lin ◽  
B. Jaensson ◽  
T. M. Holden ◽  
R. B. Rogge ◽  
J. H. Root
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Cracks ◽  
Fatigue Properties ◽  
Aircraft Industry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initiation And Propagation ◽  
Structural Parts ◽  
Compressive Residual Stresses

Sleeve coldworking (SCW) is a mechanical process used in the aircraft industry to strengthen fastener holes of structural parts. By cold-expanding the holes, compressive residual stresses and a high dislocation density are introduced around the holes, the effect of which is to counteract the initiation and propagation of fatigue cracks and thus increase the fatigue life of the parts. The knowledge of residual stress due to SCW is therefore crucial for assessing the fatigue properties of a treated part. In this study, residual stresses were investigated, by employing neutron and X-ray diffraction methods, in a lug specimen that was sleeve coldworked and fatigued. The specimen had been used for testing the influence of the SCW process on fatigue life and crack propagation behaviour under constant amplitude or variable amplitude cyclic loading.

Residual Stresses in Cold Spray Additively Manufactured Hollow Titanium Cylinders

2020 ◽  
Vol 29 (6) ◽  
pp. 1508-1524
Author(s):  
Alejandro Vargas-Uscategui ◽  
Peter C. King ◽  
Mark J. Styles ◽  
Michael Saleh ◽  
Vladimir Luzin ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Cold Spray

FATIGUE PROPERTIES OF AUTOMOBILE HIGH-STRENGTH BOLTS

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5539-5544 ◽  
Author(s):  
CONGLING ZHOU ◽  
SHIN-ICHI NISHIDA ◽  
NOBUSUKE HATTORI
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Stress Level ◽  
High Strength ◽  
Fatigue Properties ◽  
Screw Thread ◽  
Mean Stress ◽  
Stress Levels ◽  
The Mean

This study is focused on the fatigue properties of automobile high-strength bolts, including the effect of mean stress level, pre-processing schedule and the residual stresses. And the mean stress levels are 0.3, 0.5 and 0.7 times to the tensile strength (σ B ) of the material respectively. The main results obtained are as follows: 1) the fatigue strength increases under the mean stress loading, but the differences between the loading levels are not so evident; 2) most of the cases in this study are broken from the bottom of the screw thread, and the crack initiated from the impurities.

scholarly journals Mechanical and Fatigue Properties of Diamond Reinforced Cu and Al Metal Matrix Composites Prepared by Cold Spray

2021 ◽  
Author(s):  
O. Kovarik ◽  
J. Cizek ◽  
S. Yin ◽  
R. Lupoi ◽  
M. Janovska ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Cold Spray ◽  
Pure Metal ◽  
Crack Growth Resistance ◽  
Fatigue Properties ◽  
Matrix Composites ◽  
Fatigue Crack Growth Resistance

Abstract Diamond-reinforced composites prepared by cold spray are emerging materials simultaneously featuring outstanding thermal conductivity and wear resistance. Their mechanical and fatigue properties relevant to perspective engineering applications were investigated using miniature bending specimens. Cold sprayed specimens with two different mass concentrations of diamond 20% and 50% in two metallic matrices (Al – lighter than diamond; Cu – heavier than diamond) were compared with the respective pure metal deposits. These pure metal coatings showed rather limited ductility. The diamond addition slightly improved ductility and fracture toughness of the Cu-based composites; having a small effect also on the fatigue crack growth resistance. In case of the Al composites; the ductility as well as fatigue crack growth resistance and fracture toughness have improved significantly. The static and fatigue failure mechanisms were fractographically analyzed and related to the microstructure of the coatings; observing that particle decohesion is the primary failure mechanism for both static and fatigue fracture.

scholarly journals Powder Properties and Processing Conditions Affecting Cold Spray Deposition

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 91 ◽  
Author(s):  
Alessio Silvello ◽  
Pasquale Daniele Cavaliere ◽  
Vicente Albaladejo ◽  
Ana Martos ◽  
Sergi Dosta ◽  
...  
Keyword(s):  
Cold Spray ◽  
Spray Deposition ◽  
Spray Coating ◽  
Processing Parameters ◽  
Processing Conditions ◽  
Coating Properties ◽  
Spraying Parameters ◽  
Cold Spray Coating ◽  
Process Output ◽  
Powder Properties

The cold spray coating properties and performances are largely affected by feedstock characteristics and the employed processing parameters. Starting from experimental results obtained from the bibliographic data, the relationships between starting particles, processing conditions, and coating properties obtained by cold gas spray were analyzed. The relationships among these properties and particle velocity were described for various material systems. The effect on particle flattening, hardness, and porosity were largely described. Finally, the influence of the different parameters on the process output and on the coating properties was analytically defined through the employment of the multi-objective simulation tool modeFRONTIER. The analysis of data from the bibliography is a new trend that can also be applied to cold spray in order to analyze the effect of powder properties and spraying parameters on the cold spray (CS) process.

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