Kinetics of Growth of Gas-Saturated (Embrittled) Layers on Titanium during Vacuum Annealing

The influence of the parameters of the vacuum annealing mode on the thickness of the embrittled layers, formed on the surface of titanium as a result of its interaction with the residual gases of the vacuumed space, is studied. The thickness and structure of the layers were determined on samples made of VT6 alloy obtained from sheet metal with a thickness of 3 mm. Annealing of samples in the temperature range of 500-750 °C was performed with air dilution from 10 to 3∙10-2 PA. The dimensions of the embrittled layers were determined by measuring the zone of brittle crack propagation in the fracture of the samples, and measuring the distance between the surface cracks in the embrittled layers, formed during bending deformation. To quantify the effect of vacuum annealing modes of sheet titanium alloy VT6 on the depth of the embrittled part of the formed oxide layer, it is proposed to use a parabolic relationship, characterized by the degree of growth and the constant of the embrittled layer. By processing experimental data, the effect of annealing time, temperature, and air dilution on the growth kinetics of the embrittled layers was established. Based on the obtained kinetic regularities of the growth of the embrittled layers, nomograms are constructed, to determine the size of the embrittled layer formed at the heating stage at different speeds up to the specified annealing temperature.

Influence of Recrystallization Annealing Modes on the Mechanical Properties of Copper Pipes After Large Plastic Deformation

This paper presents the influence of heat treatment modes on product quality parameters. The experiments were carried out on Cu-DHP pipes at various annealing temperature and time. Grain size and mechanical properties dependence on annealing mode were plotted for phosphorus-containing copper. Laboratory results were taken into account for setting process parameters and were industrially tested.

The influence of the annealing mode on stress elimination in the foam glass structure

The purpose of this work is to establish the influence of the features of the annealing mode on the value of residual stresses in the structure of porous inorganic materials using the example of foam glass. A single-stage uniform cooling mode of foam glass with three different speeds is considered. The study was carried out using a mathematical model, the algorithm for analyzing the stress-strain state of the foam glass sample consists in solving the system of equations by the finite element method. The calculation results are presented in graphic form. The graphics show the changes in stress in the foam glass upon cooling at speeds of 100, 10 and 1 ?C min-1. The temperature difference and the viscosity values of the foam glass subsurface and central layers as a dependency of the different temperatures of the cooling onset are presented. It is concluded that it is necessary to carry out the annealing mode of foam glass in three stages: initial, glass transition step and stabilization step, meaning different cooling rates have to be applied in different stages.

Использование импульсного лазерного отжига для формирования омических контактов Mo/Ti к алмазу

The effect of pulsed laser annealing on the formation of ohmic Mo/Ti contacts to diamond is studied. Using the method of secondary-ion mass spectrometry, it was shown that laser annealing of the contacts leads to effective diffusion of carbon atoms into the titanium layer and the formation of titanium carbide in the transition region with a diamond with a thickness of 15-20 nm. Rapid thermal annealing of the same contact system is accompanied by a sharp increase in the oxygen content in the titanium layer and in the transition layer with diamond and the formation of titanium oxide. In this case, the titanium carbide phase is not formed in the Ti-C transition layer. It was also shown that, in the used laser annealing mode, graphitization of the contact layer of diamond does not occur, which could drastically reduce the mechanical strength and adhesion of the contacts.

Changing the structure and properties of hot-dip zinc coatings using diffusion annealing

Zinc coatings are widely used to protect steel goods from corrosion. The physics of methods of zinc applying to steel determines the coating morphology. Hot-dip zinc and thermodiffusion coatings are produced on steel by a diffusion mechanism and contain intermetallic phases according to the Fe-Zn diagram; however, they have different phase morphology, corrosion resistance, and consequently, different operating corrosive media. Thermodiffusion coatings have the highest corrosion resistance. However, their applying technique imposes a restraint on the dimensions of goods due to the small size of a chamber, and it requires much more time (several hours) compared to hot-dip zinc coatings applying for several minutes. In this respect, the authors suggest using the diffusion annealing of hot-dip galvanized goods to produce the entire intermetallic structure of the coating. The goal of the paper was to study the influence of the diffusion annealing modes on the microstructure and properties of hot-dip zinc coatings. The study showed the changes in the microstructure and elemental composition of the zinc coating phases as the result of soaking at the temperatures of 500 and 600 °С for 5 and 10 minutes. The authors researched the influence of annealing modes on the porosity of a coating and its microhardness. The coatings were quickly tested for corrosion resistance in the initial state and after thermal treatment. As a result of diffusion annealing, zinc coating becomes completely intermetallic, more homogeneous; its chemical composition becomes uniform. The study identified that to obtain the balance of physical-mechanical and technological properties, it is recommended to use the diffusion annealing mode with a temperature of 500 °С and soaking in a furnace for 5 minutes.

Study of the effect of local photon annealing on stress in silicon wafers

The effect of photon annealing on deformation in the crystal structure of boron doped Cz-Si wafers has been studied using triple crystal X-ray diffraction. Conventional annealing of the entire surface of double-side polished silicon wafers with halogen lamps (photon annealing mode) and rapid thermal annealing produce compression deformation. Annealing with special phototemplate providing for local annealing of multiple separated wafer areas (local photon annealing mode) at relatively low wafer temperatures (less than 55 °C) produces tensile deformation. This effect however is not observed if the reverse side of the annealed wafer contains a mechanical gettering layer. A mechanism explaining the experimental results has been suggested and can be used for the synthesis of charge pumps in photoelectric converter structures.

The Study of Ingots and Deformed Semi-Finished Products of Al-Mg-Sc and Al-Cu-Li Alloys Using Diffraction Methods

The influence of Al-Mg-Sc ingots and Al-Cu-Li semi-finished products heat treatment modes on structure, phase composition, and crystal structure was studied. Based on EBSD and EDS data, the difference of the sample microstructures was detected and the most favorable annealing mode for further deformation was presumed.

Effect of Black Plate on Growth Action and Corrosion Resistance of Sn-Fe Alloy Film

Effect of black plate on growth action and corrosion resistance of Sn-Fe alloy film was investigated by means of metallurgical microscope, scanning electron microscopy (SEM), salt spray corrosion test and electrochemistry methods. The results show that the different modes of annealing and rolling have a remarkably effects on the surface morphology and grain size of Sn-Fe alloys. Crystalline grain of Sn-Fe alloy film for T4-CA or T2.5-BA is relatively continues, homogeneous and denser, but that for DR materials exists obviously surface inhomogeneity sizes and even void space of interweave. Rust spot easily generate on discontinuous alloy films or void space of interweave growth and gradually cover on the surface of Sn-Fe alloy films without corrosion damage. Corrosion resistance of BA materials is better than that of CA materials. Under the same annealing mode, corrosion resistance of DR materials is worse.