Modifying residual stress and stress gradient in LPCVD Si3N4 film with ion implantation

2006 ◽  
Vol 130-131 ◽  
pp. 352-357 ◽  
Author(s):  
Wendian Shi ◽  
Haixia Zhang ◽  
Guobing Zhang ◽  
Zhihong Li
Keyword(s):  
Residual Stress ◽  
Ion Implantation ◽  
Stress Gradient ◽  
Si3n4 Film

scholarly journals Finite Element Modeling of Residual Stress at Joint Interface of Titanium Alloy and 17-4PH Stainless Steel

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 629
Author(s):  
Nana Kwabena Adomako ◽  
Sung Hoon Kim ◽  
Ji Hong Yoon ◽  
Se-Hwan Lee ◽  
Jeoung Han Kim
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Modeling ◽  
Equivalent Stress ◽  
Stress Gradient ◽  
Joint Interface ◽  
Element Modeling ◽  
Actual Experiment ◽  
Maximum Equivalent Stress

Residual stress is a crucial element in determining the integrity of parts and lifetime of additively manufactured structures. In stainless steel and Ti-6Al-4V fabricated joints, residual stress causes cracking and delamination of the brittle intermetallic joint interface. Knowledge of the degree of residual stress at the joint interface is, therefore, important; however, the available information is limited owing to the joint’s brittle nature and its high failure susceptibility. In this study, the residual stress distribution during the deposition of 17-4PH stainless steel on Ti-6Al-4V alloy was predicted using Simufact additive software based on the finite element modeling technique. A sharp stress gradient was revealed at the joint interface, with compressive stress on the Ti-6Al-4V side and tensile stress on the 17-4PH side. This distribution is attributed to the large difference in the coefficients of thermal expansion of the two metals. The 17-4PH side exhibited maximum equivalent stress of 500 MPa, which was twice that of the Ti-6Al-4V side (240 MPa). This showed good correlation with the thermal residual stress calculations of the alloys. The thermal history predicted via simulation at the joint interface was within the temperature range of 368–477 °C and was highly congruent with that obtained in the actual experiment, approximately 300–450 °C. In the actual experiment, joint delamination occurred, ascribable to the residual stress accumulation and multiple additive manufacturing (AM) thermal cycles on the brittle FeTi and Fe2Ti intermetallic joint interface. The build deflected to the side at an angle of 0.708° after the simulation. This study could serve as a valid reference for engineers to understand the residual stress development in 17-4PH and Ti-6Al-4V joints fabricated with AM.

Effect of Ion Implantation on the Residual Stress, Tribological and Maching Behavior of Cemented Carbide Cutting Tool Inserts Coated with TiN by CVD and PVD Methods

1997 ◽  
Vol 138-140 ◽  
pp. 177-194
Author(s):  
Anthony J. Perry ◽  
James R. Treglio ◽  
Daniel E. Geist ◽  
Deepak G. Bhat ◽  
S. Prasad Boppana ◽  
...  
Keyword(s):  
Residual Stress ◽  
Ion Implantation ◽  
Cutting Tool ◽  
Cemented Carbide ◽  
Carbide Cutting Tool

scholarly journals Evolution of Welding Residual Stresses within Cladding and Substrate during Electroslag Strip Cladding

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4126
Author(s):  
Mu Qin ◽  
Guangxu Cheng ◽  
Qing Li ◽  
Jianxiao Zhang
Keyword(s):  
Residual Stress ◽  
Classical Model ◽  
Stress Gradient ◽  
Welding Process ◽  
Welding Residual Stress ◽  
Oil Refining ◽  
Substrate Thickness ◽  
Preheat Temperature ◽  
Cladding Layer ◽  
Hydrogenation Reactor

Hydrogenation reactors are important oil-refining equipment that operate in high-temperature and high-pressure hydrogen environments and are commonly composed of 2.25Cr–1Mo–0.25V steel. For a hydrogenation reactor with a plate-welding structure, the processes and effects of welding residual stress (WRS) are very complicated due to the complexity of the welding structure. These complex welding residual stress distributions affect the service life of the equipment. This study investigates the evolution of welding residual stress during weld-overlay cladding for hydrogenation reactors using the finite element method (FEM). A blind hole method is applied to verify the proposed model. Unlike the classical model, WRS distribution in a cladding/substrate system in this study was found to be divided into three regions: the cladding layer, the stress-affected layer (SAL), and the substrate in this study. The SAL is defined as region coupling affected by the stresses of the cladding layer and substrate at the same time. The evolution of residual stress in these three regions was thoroughly analyzed in three steps with respect to the plastic-strain state of the SAL. Residual stress was rapidly generated in Stage 1, reaching about −440 MPa compression stress in the SAL region at the end of this stage after 2.5 s. After cooling for 154 s, at the end of Stage 2, the WRS distribution was fundamentally shaped except for in the cladding layer. The interface between the cladding layer and substrate is the most heavily damaged region due to the severe stress gradient and drastic change in WRS during the welding process. The effects of substrate thickness and preheat temperature were evaluated. The final WRS in the cladding layer first increased with the increase in substrate thickness, and then started to decline when substrate thickness reached a large-enough value. WRS magnitudes in the substrate and SAL decreased with the increase in preheat temperature and substrate thickness. Compressive WRS in the cladding layer, on the other hand, increased with the increase in preheat temperature.

scholarly journals Stress Gradient Analysis by Noncomplanar x-Ray Diffraction and Corresponding Refraction Correction

2014 ◽  
Vol 996 ◽  
pp. 162-168 ◽  
Author(s):  
Andrei Benediktovitch ◽  
Tatjana Ulyanenkova ◽  
Jozef Keckes ◽  
Alex Ulyanenkov
Keyword(s):  
Residual Stress ◽  
Gradient Analysis ◽  
Stress Gradient ◽  
X Ray Diffraction ◽  
Large Area ◽  
Present Contribution ◽  
Nondestructive Technique ◽  
X Ray ◽  
Tin Coatings ◽  
Measurement Geometry

X-ray residual stress analysis is a widespread nondestructive technique to investigate the residual stress and residual stress gradient in thin films and protective coatings.In the present contribution we introduce a new method based on the noncomplanar measurement geometry that allow to span large area of sin2ψ and penetration depth values without sample inclination. The refraction correction and absorption is considered in details for the noncomplanar measurements. The proposed technique is applied to determine stress gradients of blasted hard TiN coatings.

Residual stress gradient analysis with GIXRD on ZrO2 thin films deposited by MOCVD

2011 ◽  
Vol 206 (2-3) ◽  
pp. 405-410 ◽  
Author(s):  
Zhe Chen ◽  
Nathalie Prud'homme ◽  
Bin Wang ◽  
Vincent Ji
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Gradient Analysis ◽  
Stress Gradient ◽  
Residual Stress Gradient

scholarly journals Influence of Welding Defects on Residual Stresses: Numerical Study

2014 ◽  
Vol 996 ◽  
pp. 506-511
Author(s):  
Intissar Frih ◽  
Pierre Antoine Adragna ◽  
Guillaume Montay
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Numerical Study ◽  
Stress Gradient ◽  
Residual Stress Distribution ◽  
Welded Structure ◽  
Critical Defect ◽  
Welding Defects ◽  
Residual Stress Gradient

This paper presents a study on the application of the finite element methods to predict the influence of a defect on the residual stress distribution in a T-welded structure. A defect is introduced in a numerical model firstly without residual stress to see its impact (size and position) on the stress distribution. Secondly the most critical defect (determined previously) is simulated with a residual stress gradient. The obtained results are useful for computation stress concentration factor due to weld residual stresses.

Influence of Surface Roughness on the Quality of Data Obtained by Pseudo-Grazing Incidence X-Ray Diffraction

2006 ◽  
Vol 514-516 ◽  
pp. 1618-1622 ◽  
Author(s):  
Maria José Marques ◽  
J.C.P. Pina ◽  
A. Morão Dias
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Stress Gradient ◽  
Roughness Parameter ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
Residual Surface Stress ◽  
X Ray

The conventional Bragg diffraction geometry, normally used to characterize the residual surface stress state, it is not suitable to evaluate surface treated materials and thin films. The X-ray path lengths through a surface layer or thin film are too short to produce adequate diffraction intensities in relation to the bulk or the substrate. Another limitation of the conventional technique appears when a residual stress gradient is present in the irradiated surface. The technique only enables the evaluation of the mean value of this gradient. In these cases, a recently proposed Pseudo-Grazing Incident X-ray Diffraction method would be better applicable. In this study, the Pseudo-Grazing Incidence X-ray Diffraction is applied to characterize the residual stress depth profiles of several AISI 4140 samples, which were prepared, by mechanical polishing and grinding, in order to present different surface roughness parameters, Ra. The experimental results lead to the conclusion that the surface roughness limits the application of the Pseudo-Grazing Incidence methodology to a minimum X-ray incident angle. This angle is the one that enables a mean X-ray penetration depth with the same order of magnitude of the sample surface roughness parameter, Ra.

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