scholarly journals Monitoring of Thermal Aging of Aluminum Alloy via Nonlinear Propagation of Acoustic Pulses Generated and Detected by Lasers

2019 ◽  
Vol 9 (6) ◽  
pp. 1191 ◽  
Author(s):  
Mengmeng Li ◽  
Alexey Lomonosov ◽  
Zhonghua Shen ◽  
Hogeon Seo ◽  
Kyung-Young Jhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Thermal Aging ◽  
Finite Amplitude ◽  
Quadratic Nonlinearity ◽  
Laser Ultrasonic ◽  
Ultrasonic Techniques ◽  
Non Destructive

Nonlinear acoustic techniques are established tools for the characterization of micro-inhomogeneous materials with higher sensitivity, compared to linear ultrasonic techniques. In particular, the evaluation of material elastic quadratic nonlinearity via the detection of the second harmonic generation by acoustic waves is known to provide an assessment of the state variation of heat treated micro-structured materials. We report on the first application for non-destructive diagnostics of material thermal aging of finite-amplitude longitudinal acoustic pulses generated and detected by lasers. Finite-amplitude longitudinal pulses were launched in aluminum alloy samples by deposited liquid-suspended carbon particles layer irradiated by a nanosecond laser source. An out-of-plane displacement at the epicenter of the opposite sample surface was measured by an interferometer. This laser ultrasonic technique provided an opportunity to study the propagation in aluminum alloys of finite-amplitude acoustic pulses with a strain up to 5 × 10−3. The experiments revealed a signature of the hysteretic quadratic nonlinearity of micro-structured material manifested in an increase of the duration of detected acoustic pulses with an increase of their amplitude. The parameter of the hysteretic quadratic nonlinearity of the aluminum alloy (Al6061) was found to be of the order of 100 and to exhibit more than 50% variations in the process of the alloy thermal aging. By comparing the measured parameter of the hysteretic quadratic nonlinearity in aluminum alloys that were subjected to heat-treatment at 220 °C for different times (0 min, 20 min, 40 min, 1 h, 2 h, 10 h, 100 h, and 1000 h), with measurements of yield strength in same samples, it was established that the extrema in the dependence of the hysteretic nonlinearity and of the yield strength of this alloy on heat treatment time are correlated. This experimental observation provides the background for future research with the application goal of suggested nonlinear laser ultrasonic techniques for non-destructive evaluation of alloys’ strength and rigidity in the process of their heat treatment.

scholarly journals Possibilities of using scanning acoustic microscopy to analyze incompatibilities in braze welded joints

2019 ◽  
Vol 91 (10) ◽  
pp. 7-15
Author(s):  
Tomasz Piwowarczyk ◽  
Marcin Korzeniowski ◽  
Dawid Majewski
Keyword(s):  
Aluminum Alloys ◽  
Welded Joints ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Ultrasonic Techniques ◽  
Titanium Grade ◽  
Non Destructive

This article explores the possibilities of using non-destructive ultrasonic techniques to analyze the quality of lapped braze-welded joints. The tests were performed for 4 material groups (DC03+ZE steel and X5CrNi18-19 steel, aluminum alloys AW-5754 and AW-6061, titanium Grade 2 and copper Cu-ETP). As part of the work, additional materials and joint processes and its parameters were selected (TIG, MIG, laser). The quality of joints was monitored using scanning acoustic microscopy. Based on the A-scan andC-scan images, potential joints imperfections were determined. The possibilities of using advanced ultrasonic techniques to analyze the quality of braze joints was assessed.

scholarly journals EN AW-2024 Wrought Aluminum Alloy Processed by Casting with Crystallization under Pressure

2017 ◽  
Vol 67 (2) ◽  
pp. 109-116
Author(s):  
Branislav Vanko ◽  
Ladislav Stanček ◽  
Roman Moravčík
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Shrinkage Porosity ◽  
Forced Flow ◽  
Heat Treated ◽  
Crystallization Under Pressure ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum

AbstractBy using the wrought aluminum alloys can be created castings with higher mechanical properties than the castings made of standard foundry aluminum alloys, but it is necessary to handle the process of making sound castings without any defects such as hot tears and shrinkage porosity. In experiments, we have been studied of wrought aluminum alloy EN AW-2024 which has been processed by the casting with crystallization under pressure with forced flow. Castings were heat treated by standard T6 heat treatment.

scholarly journals 2D size, position and shape definition of defects by B-scan image analysis

2015 ◽  
Author(s):  
Michele Scafidi ◽  
Donatella Cerniglia ◽  
Tommaso Ingrassia
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Automatic Inspection ◽  
Structural Components ◽  
Laser Ultrasonic ◽  
Non Destructive Evaluation ◽  
Ultrasonic Techniques ◽  
Definition Of ◽  
B Scan Images ◽  
Non Destructive

The non-destructive evaluation of defects by automatic procedures is of great importance for structural components. Thanks to the developments of the non-contact ultrasonic techniques, the automation of the inspections is gaining a progressively important role. In this work, an automatic inspection technique for the evaluation of defects by the analysis of B-scan images obtained by a laser ultrasonic system is presented. The data are extracted directly from a B-scan map obtained for a panel with internal defects, and are used to build an image of the cross section of the panel. The proposed automatic procedure allows the definition of size, position and shape of defects in panels of known thickness.

scholarly journals Improving of Surface Quality of Metal Reflector Mirrors Machined by Single Point Diamond Turning

2021 ◽  
Vol 12 (2) ◽  
pp. 139-145
Author(s):  
G. A. Gusakov ◽  
G. V. Sharonov
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Surface Treatment ◽  
Radiation Resistance ◽  
Single Point ◽  
Diamond Turning ◽  
Laser Damage Threshold ◽  
Complete Disappearance

Improving the technology of diamond turning of aluminum alloys is of great importance for expanding the application areas of metal-optical products based on aluminum in aerospace technology. The aim of this work was to study the effect of surface inhomogeneities of the initial aluminum alloy substrates on their optical and mechanical characteristics and to determine ways of improving the quality of aluminum reflector mirrors manufactured using nanoscale single point diamond turning. The investigated reflector mirrors were made from AMg2 aluminum alloy. The optical surface treatment was carried out on a precision turning lathe with an air bearing spindle using a special diamond cutter with a blade radius of ≤ 0.05 μm. The analysis of the surface structure of the AMg2 alloy substrates was carried out by scanning electron microscopy / electron microprobe. The quality control of the surface treatment of the manufactured reflector mirrors was carried out by atomic force microscopy. The reflectivity and radiation resistance of these samples were also investigated.It is shown that an important problem in the manufacture of optical elements from aluminum alloys is the inhomogeneity of the structure of the initial material, associated with the presence of intermetallic inclusions. Heat treatment of the AMg2 alloy substrates at T ≥ 380 °C makes it possible to improve the quality of surface and the radiation resistance of aluminum mirrors both by removing mechanical stresses and by partially homogenizing the starting material. The optimum is heat treatment at the maximum allowable temperature for the AMg2 alloy T = 540 ºС, as a result of which there is a complete disappearance of intermetallic inclusions with an increased magnesium content. The use of high-temperature heat treatment of AMg2 alloy substrates allows, in comparison with unannealed samples, to reduce the surface roughness from 1.5 to 0.55 nm, to increase the reflectivity of mirrors at a wavelength of 1064 nm from 0.89 to 0.92, and to increase the laser damage threshold from 3.5 to 5 J / cm2.

Yield Strength Prediction for Rapid Age-Hardening Heat Treatment of Aluminum Alloys

2013 ◽  
pp. 87-94
Author(s):  
Hebi Yin ◽  
Adrian S. Sabau ◽  
Gerard M. Ludtka ◽  
Timothy W. Skszek ◽  
Xiaoping Niu
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Age Hardening ◽  
Strength Prediction ◽  
Hardening Heat Treatment

Wrought Aluminum Alloy: Reinforcement, Alloy Addition, and Deformation Effects on Mechanical Responses

2019 ◽  
Author(s):  
Samson Oluropo Adeosun ◽  
E. I. Akpan ◽  
S. A. Balogun
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Silicon Carbide ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Good Prospect ◽  
Reinforcing Particles ◽  
Alloy Addition ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum

This article discusses the effects of various modifications on the properties of aluminum alloys for structural applications. The effect of reinforcing particles on the mechanical properties of wrought 6063 aluminum alloy arising from our previous works is extensively discussed to identify the most promising reinforcing particles. It also discusses the improvement in mechanical properties of 1200 aluminum alloy using silicon carbide particulates. The effect of micro-alloy additions on the mechanical properties is also outlined in this article based on the results from our previous experimental works. Effect of combining heat treatment and deformation on the mechanical properties of wrought aluminum alloys is also presented. Results presented show that particle reinforcement, deformation, and microelemental additions to aluminum alloy result in significant improvement in mechanical properties of the alloys considered. Addition of reinforcing particles of barite, silicon carbide, iron fillings, and electric arc furnace dust are found to impart improved tensile strength to aluminum alloy. The most outstanding finding is that synergy between particle addition, deformation, and heat treatment has a good prospect in the production of improved aluminum alloy materials for automotive applications.

Effect of Heat Treatment Conditions on Tube Hydroforming Characteristics of Aluminum Alloy

2013 ◽  
Vol 535-536 ◽  
pp. 275-278
Author(s):  
Myeong Han Lee ◽  
Young Chul Shin ◽  
Duk Jae Yoon
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Treatment Processes ◽  
Forming Technology ◽  
Treatment Conditions ◽  
Compressive Loads ◽  
Hydroforming Process

Tube hydroforming is a metal forming technology that utilizes internal pressure and axial compressive loads to generate designed product shapes with complex sections from tubular materials. The tube hydroforming process has been used in the automotive, aircraft, and bicycle industries for many years. With the pursuit of lighter bicycles, aluminum alloys have been utilized as an alternative to steel. To obtain adequate strength, the aluminum alloys should undergo heat treatment processes before being used. However, the mechanical properties of the alloys vary with the tempering conditions. This paper aims to evaluate the effects of tube hydroforming characteristics on different kinds of tempered aluminum alloys. Based on numerical simulations, suitable tube hydroforming processing conditions for each tempered aluminum alloy are suggested.

Intermediate Heat Treatment – A New Proceeding for Aluminum Alloys Using Forming Limit Diagrams

2011 ◽  
Vol 473 ◽  
pp. 428-435 ◽  
Author(s):  
Kathleen Siefert ◽  
Marion Merklein ◽  
Almut Töpperwien ◽  
Winfried Nester ◽  
Martin Grünbaum
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Strain Hardening ◽  
Room Temperature ◽  
Forming Limit ◽  
Cold Forming ◽  
Intermediate Heat Treatment ◽  
Heat Treated ◽  
Strain Paths

This paper presents a new procedure for a heat treatment embedded between two cold forming steps. A first cold forming step induces a defined strain hardening in the material. The following step is the heat treatment which takes place in a furnace at various temperatures and for certain durations. The application of such an intermediate heat treatment reduces the strain hardening of the material and enhances the elongation. This allows a higher degree of deformation in the second cold forming operation. The achievable properties of the aluminum alloy AlMg4.5Mn (AA5182) were discussed in detail. Further investigations using Nakajima test setup revealed an increased formability of the material. First the Nakajima samples were pre-strained along different linear strain paths to a predefined strain value. Afterwards the samples were heat treated without allowing the aluminum alloy to recrystallize. After cooling down the samples to room temperature, the tests are continued until the material’s fracture. As a result heat treatment dependent forming limit curves (FLC) are obtained. In comparison with a measured FLC at room temperature the support of the intermediate heat treatment on enhanced formability were shown. Furthermore the method is not restricted to AA5182 aluminum alloys.

Mechanical and Fatigue Performance Tests of Cast Aluminum Alloy ZL111 Adopted in Structure

2010 ◽  
Vol 168-170 ◽  
pp. 1961-1969 ◽  
Author(s):  
Yuan Qing Wang ◽  
Huan Xin Yuan ◽  
Yong Jiu Shi
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Carbon Steel ◽  
Aluminum Alloys ◽  
Low Temperatures ◽  
Room Temperature ◽  
Raw Materials ◽  
High Strength ◽  
Fatigue Performance

Characteristics of aluminum alloys such as light weight, high strength-to-weight ratio and favorable corrosion resistance have brought about a bright application prospect in building structures. Wrought alloys are applicable to common beams and columns, while casting alloys can be fabricated as connectors in point-supported glass curtain wall and joints in spatial latticed structures on account of easy implement of moulding. Because of high strength, outstanding castability and remarkable mechanical properties after heat treatment, ZL111 in aluminum-silicon alloys is regarded as a desirable option. However, aluminum alloys are non-linear materials and their properties vary with casting and heat treatment modes. It is the well-marked distinction between aluminum alloy and ordinary carbon steel that special study on mechanical and fatigue performance is required. ZL111 raw materials were selected, with alloying agent and fabrication processes meeting the requirement of GB/T 1173-1995 standard. After T6 heat treatment process, test coupons were obtained by machining from raw materials. By utilization of electronic universal testing machine and cryogenic box, tensile tests at room temperature and low temperatures were performed. High-circle fatigue tests were carried out to obtain the fatigue performance of the material. Scanning electron microscope (SEM) was introduced to observe morphology of tensile and fatigue fractures. The tests revealed the relationship between mechanical property index and temperature, which indicated that the ZL111-T6 would increase in strength and plasticity. The microstructure of fractures validated and explained the macroscopic results. Furthermore, material strength at room temperature or low temperatures, stiffness and fatigue performance could satisfy bearing and normal serviceability requirement. Because of non existence of ductile-brittle transition temperature, superior corrosion resistance and outstanding castability, ZL111-T6 material is prone to fabricate complicated elements and joints withstanding cryogenic environment instead of carbon steel.

NORAL C77S

Alloy Digest ◽  
1953 ◽  
Vol 2 (11) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Precipitation Hardening ◽  
High Strength ◽  
Heat Treating ◽  
Bearing Strength ◽  
Wrought Aluminum ◽  
Hardening Heat Treatment

Abstract NORAL C77S is a high strength, heat treatable, wrought aluminum alloy that is recommended for highly stressed components. It responds to the precipitation hardening heat treatment, producing tensile strengths in excess of all other aluminum alloys. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as fracture toughness and fatigue. It also includes information on as well as forming, heat treating, machining, and joining. Filing Code: Al-10. Producer or source: Northern Aluminium Company Ltd.

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