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.

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.

Evaluation on Microstructure of Aluminum Alloys Dedicated to Plasma Etcher

2011 ◽  
Vol 689 ◽  
pp. 343-349
Author(s):  
Zhi Hui Zhang ◽  
Shu Feng Liu ◽  
Ze Ming Sun ◽  
Xiao Dong Yan
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Anodic Oxidation ◽  
Scientific Basis ◽  
Secondary Phases ◽  
6061 Aluminum Alloy ◽  
Close Relationship ◽  
The Matrix ◽  
Hole Defects

The relationship between microstructure and anodic oxidation film on 6061 aluminum alloy dedicated to plasma etcher were mainly studied by OM, SEM and TEM. The results show that the quality of anodic oxidation film has close relationship with the microstructure of materials, the distribution of element and the morphology of secondary phases. The microstructure of foreign 6061 aluminum alloy is uniform, and there are not obviously segregation and cavity. Two kinds of secondary phases disperse over the grain, one is rich-Fe phase, and the other is Mg2Si. Certainly there are also few secondary phases distributing along the grain boundary. The sizes of all secondary phases are almost below 5mm. The size of rich-Fe phases in homemade aluminum alloys are about from 2mm to 15mm, these big-size phases will bring pin-hole defects, which form some channels sending F+ etc. into the matrix of aluminum alloy, then not only the equipment will be destroyed at last, but also products will be polluted. The evaluation on microstructure of aluminum alloy will provide scientific basis for nationalization of plasma etcher.

A Study of Cutting Strategy in Single-Point Diamond Turning of Micro V-Groove Patterns on Precision Roller Drums

2014 ◽  
Vol 625 ◽  
pp. 742-747
Author(s):  
C.H. Mak ◽  
C.F. Cheung ◽  
M.J. Ren ◽  
L.B. Kong ◽  
S. To
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Cutting Parameters ◽  
Diamond Turning ◽  
Surface Generation ◽  
Depth Of Cut ◽  
Tool Paths ◽  
Cutting Strategy ◽  
Groove Pattern

This paper presents a study of cutting strategies on the surface generation in single-point diamond turning of micro V-groove patterns on precision roller drums. An aluminium precision roller drum with a diameter 250mm and 100 long was diamond turned with a V-groove pattern. A series of cutting experiments were designed to study the effect of the variation of various cutting parameters and cutting tool paths on the surface quality in diamond turning of the precision roller drum. The parameters under investigation included the depth of cut, number of steps and the depth for each cut when diamond turning V-grooves on the cylindrical surface of a workpiece. The measurement result indicates that the surface quality of V-grooves machined on the precision roller drums is affected by cutting strategies. The optimal cutting strategy for machining a V-groove pattern on a precision drum with 5µm depth was obtained.

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 Change in the surface structure and the oxide layer of the Ti6Al4V ELI alloy as a result of mechanical and heat treatment

2021 ◽  
pp. 12-21
Author(s):  
Michał SZOTA
Keyword(s):  
Heat Treatment ◽  
Surface Treatment ◽  
Oxide Layer ◽  
Mechanical Treatment ◽  
Optical Microscope ◽  
Pure Metal ◽  
Test Results ◽  
Roughness Parameters ◽  
Surface Development

Surface treatment, both mechanical, chemical and thermal causes a number of changes to the external structure of meterial details. The obtained properties are intended to improve the quality of material details made of a given alloy or pure metal. This paper presents the results of mechanical surface treatment to the thickness of the oxide layer after heat treatment of the TU6Al14V ELI alloy. The experiments were performed for a rod with a diameter of 5 mm cut into semicircular slices. The samples were mechanically activated by mechanical treatment of the surface: sandblasting with glass balls for 5 minutes, sanded with 40, 180, 220 and 800 grit sandpaper for 7.5 and 15 minutes.Using an optical microscope, the microstructure of the samples etched with Kroll's solution was assessed and the surface roughness parameters were measured.The next step was to carry out the heat treatment (at the temperature of 550 oC, for 5 hours), and then the roughness parameters and the thickness of the oxide layer were measured using a scanning microscope.The conducted research has shown that mechanical treatment of the surface resulting in an increase in surface development causes an increase in the thickness of the oxide layer formed during heat treatment. However, machining to reduce surface development, such as polishing, reduces the thickness of the oxide layer.The test results can be used to obtain the desired thickness of the oxide layer in the production of elements requiring increased resistance to wear or corrosion.

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.

Ultra-Precision Turning Technology of Gold Cone in Fast Ignition

2013 ◽  
Vol 562-565 ◽  
pp. 147-151
Author(s):  
Guo Li ◽  
Yan Hua Huang ◽  
Wei Chao Tong ◽  
Guang Hui Yuan ◽  
Yang Tao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wall Thickness ◽  
Single Point ◽  
Fast Ignition ◽  
Diamond Turning ◽  
End Effect ◽  
Processing Parameter ◽  
Ultra Precision ◽  
Cone Surface

Fast Ignition (FI) attracts much attention owing to its advantages. The fabrication of fast ignition targets is one of the key technologies in FI study. Based on the single point diamond turning (SPDT) technology, Diamond post-turning method is adopted in this paper for the fabrication of gold cone. It not only helps to reduce the end-effect of cone mandrel and consequently improve the coaxiality of internal and external cone surface, but also helps to improve the quality of cone surface and the wall thickness consistency. Besides, the processing parameter of diamond post-turning is experimentally studied in this paper for its effect on the cone surface roughness. According to results, the cone surface roughness is Ra 9.21nm, the wall thickness consistency is 3μm and the cone end surface roughness is Ra5.72nm。

scholarly journals PRODUCTION OF ROTARY ENGINES’ PARTS FROM ALUMINUM ALLOYS USING LOST FOAM CASTING PROCESS

2018 ◽  
pp. 16-21
Author(s):  
E. I. Marukovich ◽  
A. M. Branovitskiy ◽  
A. A. Kruglov ◽  
V. A. Dement’ev ◽  
N. P. Sadovskiy
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Production Technology ◽  
Casting Process ◽  
Expanded Polystyrene ◽  
Lost Foam Casting ◽  
Rotary Engine ◽  
Rotary Engines ◽  
Lost Foam

The production technology of casting details for rotary engine from the aluminum alloy АК12М2 is developed. The bulk density of expanded polystyrene to ensure the best quality of the surface of castings has been experimentally established. The lost foam casting shop was organized in the experimental department of the Institute.

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