RU2131331C1 - Solid material machining apparatus - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: apparatus is formed as solid body with working part made from hard alloy containing ferromagnetic binder introduced into surface layer of working part of solid body, with concentration of metal cobalt being at least 0.3% by weight, and layer thickness being at least 2.0 microns. Service life of working part of apparatus is increased by 6 times as compared to known construction. EFFECT: increased efficiency and service life, improved quality of worked products. 2 cl, 4 dwg, 2 tbl, 2 ex

Description

 The invention relates to the field of mechanical engineering, mainly to cold and hot machining of metals, in particular to devices, the working part of which is carbide tool.

 A device for machining solid materials is known, which is a solid body, the working part of which is made of a hard alloy based on titanium carbide with an iron binder (carbide steel) [1].

 A device for machining solid materials is known, which is a solid body, the working part of which is made of a hard alloy based on tungsten monocarbide with a nickel binder [2].

 Closest to the claimed device is a device for machining solid materials, which is a solid body, the working part of which is made of a hard alloy based on tungsten monocarbide with a cobalt bond [3].

 The disadvantages of the known devices are: the wear resistance of devices with a working part of a composition of TiC-Fe is lower than that of a working part of a device of a composition WC-Co, the strength, hardness and wear resistance of devices with a working part of a WC-Ni is lower than that of a working part of a device of a composition WC-Co, the distribution of cobalt in the working part of the devices is often very heterogeneous and its content in the surface layer is lower than in the rest of the volume.

 The aim of the present invention is the possibility of obtaining a "wear-resistant coating", embedded in the surface layer of the working part of the device and allowing up to six times to increase its service life.

 This goal is achieved by the fact that the ferromagnetic binder - metal cobalt and solid solutions based on it - is introduced into the surface layer of the working part of the body, and the concentration of metallic cobalt is at least 0.3 mass percent, and the layer thickness is at least 2.0 μm.

 The positive effect of the creation and use of the present invention is manifested in the fact that cobalt metal and solid solutions based on it, introduced into the surface layer of the working hard-alloy part of the device, form, together with the carbides of refractory metals, a "wear-resistant coating", which has a larger compared to the rest of the working partly ductility, in that the "wear-resistant coating" has perfect adhesion, as it is a near-surface area of the working part of carbide material, in that The indicated arrangement of metallic cobalt and solid solutions based on it in the near-surface region of the working carbide part of the device allows the application of known methods of radiation treatment to it, which increase the service life of the device several times.

 The list of graphic images.

FIG. 1 is a depth distribution profile of cobalt concentration in a T15KG carbide cutting insert (sample No. 1); FIG. 2 is a depth distribution profile of cobalt concentration in a T15KG carbide insert (sample No. 2); FIG. 3 - distribution profile of the depth of cobalt concentration in a cutting plate of VK3M carbide (sample N 3). Spraying time t _p = 7 min 21 s; FIG. 4 is a depth distribution profile of cobalt concentration in a carbide cutting insert (sample No. 3). Spray time t _p = 23 min 34 s.

 The essence of the claimed invention is illustrated by the following description.

 The invention is based on an analysis of the results of numerous experiments on radiation hardening of carbide tools that we conducted in recent years. Their essence briefly boils down to the following: radiation treatment (irradiation with fast electrons, protons, α-particles or γ-quanta) increases the wear resistance and service life of carbide products several times only when the method of X-ray diffraction analysis (X-ray diffractometry) records the phase of the metal cobalt in the surface layer of the product. This conclusion directly implies the conclusion about the depth of the surface layer, and in combination with other methods of analysis, information on the value of the threshold concentration of cobalt can be obtained from it.

Глубину проникновения рентгеновского излучения в твердосплавное изделие можно определить, если известны значения массового коэффициента ослабления для компонентов твердого сплава. Массовый коэффициент ослабления твердосплавного изделия можно в общем случае определить по формуле [4]

где μ, μ_i - линейные коэффициенты ослабления рентгеновского излучения в материале изделия и в его компонентах соответственно;
ρ, ρ_i - плотности материала изделия и его компонентов;
a_i - весовая доля компонента.a) the thickness of the surface layer
When studying the phase composition of carbide products based on tungsten monocarbide with a cobalt bond, X-ray diffractometry usually uses radiation

The depth of penetration of x-rays into the carbide product can be determined if the values of the mass attenuation coefficient for the components of the hard alloy are known. The mass attenuation coefficient of the carbide product can in general be determined by the formula [4]

where μ, μ _i are the linear attenuation coefficients of x-ray radiation in the material of the product and in its components, respectively;
ρ, ρ _i - the density of the material of the product and its components;
a _i is the weight fraction of the component.

, причем получено хорошее совпадение результатов.From formula (1) it follows that for hard alloys of various compositions the ratio μ / ρ takes different values. The 2nd column of Table 1 shows the μ / ρ values calculated by formula (1) for some grades of hard alloys. The values of μ _i / ρ _i were taken from the table of the monograph [4] and checked according to the Ionsson tables [5] and the nomogram given in [5] with allowance for the absorption jumps S _K and

and moreover, a good agreement of the results is obtained.

 To determine the values of μ for hard alloys of various compositions, it is also necessary to know the value of ρ - the density of each hard alloy. Taken from GOST 3882-74 and averaged by us ρ values are given in the 3rd column of the table. 1 (see table. 1, 2 at the end of the description). In the 4th column of the table. 1 shows the values of linear attenuation coefficients for some hard alloys.

 In studies of the phase composition by x-ray diffractometry, the depth of the layer involved in the formation of the diffraction pattern is usually calculated by the formula [4].

где ϑ - угол между плоскостью падения и направлением падения рентгеновских лучей на нее;
K_x - коэффициент, значения которого приведены в монографии [4] для различных значений g_x - части интенсивности рентгеновского излучения, рассеянного в слое толщиной x.

where ϑ is the angle between the plane of incidence and the direction of incidence of x-rays on it;
K _x is the coefficient, the values of which are given in the monograph [4] for various values of g _x - part of the intensity of x-ray radiation scattered in a layer of thickness x.

So, for g _x = 0.50 K _x = 0.69; for g _x = 0.60 K _x = 0.92; for g _x = 0.70 K _x = 1.20; for g _x = 0.80 K _x = 1.61; for g _x = 0.90 K _x = 2.3; for g _x = 0.95 K _x = 3.0; for g _x = 0.97 K _x = 3.5; for g _x = 0.99 K _x = 4.6
In our case, when observing cobalt in hard alloys, the angle is ϑ ≅ 28 ^o and sinϑ = 0.4695. In the table. Figure 2 shows the x values calculated by formula (2) for some g _x values for various hard alloys.

The main experiments, the results of which are partially described below, were carried out with cutting inserts made of hard alloys VK3M, VK8, T15K6, MS 111, MS 321. For g _x = 0.90, the value of x varies from 2.20 μm to 3, 26 microns, for g _x = 0.95 - from 2.86 microns to 4.24 microns. Due to the fact that, firstly, the value of g _x for a particular experiment is known very approximately and, secondly, with a further decrease in the cobalt content in the hard alloy, the value of x will decrease, as threshold values we choose for WC g _x = 0 , 90 and μ _WC = 2600 cm ^-1 (x = 2.08 μm). With an accuracy of 0.08 μm, i.e. 3.8% of the last value is chosen equal to 2.0 microns.

b) The concentration of cobalt
It is possible to determine the concentration of metallic cobalt, starting with which the X-ray diffractometry method does not distinguish it, based on specially set experiments. The description of some experiments below gives only a rough estimate of the analyzed threshold.

 On two T15K6 carbide cutting inserts, the cobalt content in the surface layer was determined by X-ray diffractometry. Cobalt was detected on one of the plates (N 1), but not on the other (N 2). Then, on the grinding machine, the surface layer was removed on both samples. In the depths of the plates, cobalt metal was observed by X-ray diffractometry on both plates and its concentration was approximately the same. Prior to the start of these experiments, the content (integral) of cobalt metal in both plates was determined by an independent method — magnetic measurements — and amounted to 5.21 mass% in sample No. 1. %, in sample N 2 5.17 wt.%. Thus, in this series of experiments, the X-ray diffractometry method confidently recorded the concentration of metallic cobalt in the near-surface layer of at least 5.17 wt. %, and "did not notice" cobalt with a concentration that will be estimated below.

 In another series of experiments, a different model of the X-ray diffractometer was used, operating in a mode that provided somewhat greater sensitivity. In this series of experiments, the content of metallic cobalt in hard alloys of various compositions was studied by magnetic measurements and X-ray diffractometry. In this case, the X-ray method confidently detected the presence of cobalt metal on the surface of the VK3M alloy, and magnetic measurements confirmed that the integral content of cobalt metal in the sample was 2.99 wt.%.

 However, the cobalt content in the surface layer of the carbide product recorded by the X-ray diffractometer is not at all equal in accuracy to its content in the volume, which is equal to approximately 3 wt.% In the case of VK3M alloy. % In fact, the cobalt content in the surface layer of the carbide product is lower than in volume. The lower cobalt content in this layer is associated with the evaporation of cobalt from the surface of the product during its sintering.

 To estimate the cobalt loss from the surface of the product, one could calculate using the formula given in the monograph [6] giving the number of particles vaporizing per unit time from a unit surface of the material and related to the vapor pressure of chemical elements [7], which depends on the heating temperature. However, the exact time and temperature conditions and conditions (vacuum, hydrogen) of sintering are unknown to us, so we will go a different way.

 For a more rigorous assessment of the concentration of cobalt in the surface layers of samples 1 and 2, we turn to the results of measurements by the SIMS method (Figs. 1 and 2). The SIMS method recorded a sharp (by 3 orders of magnitude) drop in the cobalt concentration in the near-surface layer of sample No. 1 (see Fig. 1). The exact value of those depths at which the concentration of cobalt in the surface layers of the samples becomes equal to the concentration of cobalt in the volume of products is unknown to us. Therefore, we restrict ourselves to approximate estimates below.

и

Ho при облучении ионами кислорода углерода (основного компонента всех карбидов) имеет место так называемое "химическое распыление" [8], для которого коэффициент распыления при E = 7,9 кэВ несколько превышает единицу (S = 1,05 aт.C/O $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ ). Положим, что коэффициент распыления монокарбида вольфрама ионами кислорода также равен 1,05. Согласно данным, представленным на профилях W, Ti, C и Co в приповерхностных слоях образцов 1 и 2, полное время распыления составило t_1р = 22 мин 23 с = 1343 с и t_2р = 16 мин 59 с = 1019 с. Следовательно, за время t_1р распылится N_1WC = 1,44•10¹⁵ 1,05•1,343•10³ молекул WC/см² = 2,035•10¹⁸ WC/см² ≈ 2,04•10¹⁸ WC/см² (считаем, что вместе с каждым распыленным атомом углерода удаляется и атом вольфрама). Соответственно, за время t_2р распылится N_2WC = 1,47•10¹⁸•1,05•1,019 WC/см² = 1,57•10¹⁸ WC/см². Но концентрация молекул WC равна

За время t_р удалено N_WC молекул WC/см². Поэтому толщина распыленного слоя d равна

Оценим теперь реальную величину концентрации кобальта, регистрируемую рентгеновским дифрактометром.First of all, let us estimate the thickness of the surface layer removed during the study in samples 1 and 2 of the cobalt profile by the SIMS method. When studying the profiles of tungsten (W), carbon (C), titanium (Ti) and cobalt (Co) in the T15K6 hard alloy by the SIMS method for atomization, bombardment with oxygen ions with an energy of 7.9 keV was used. The ion current was 144 nA (sample N 1) and 147 nA (sample N 2). A square area with a side of 250 μm was irradiated with ions. A square field with a side of 8 μm was analyzed. Therefore, the ion current density was: j ₁ = J ₁ / S = 1.44 • 10 ^-7 A / 6.25 • 10 ^-4 cm ² = 1.44 • 10 ^-3 / 6.25 A / cm ² and j ₂ = J ₂ / S = 1.47 • 10 ^-3 / 6.25 A / cm ² . These values correspond to certain amounts of oxygen ions O $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ falling in 1 s per unit surface

and

Ho when irradiated with carbon oxygen ions (the main component of all carbides), the so-called “chemical sputtering” takes place [8], for which the sputtering coefficient at E = 7.9 keV is slightly greater than unity (S = 1.05 at. C / O $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ ) Suppose that the sputtering coefficient of tungsten monocarbide by oxygen ions is also equal to 1.05. According to the data presented on the W, Ti, C, and Co profiles in the surface layers of samples 1 and 2, the total spraying time was t _1p = 22 min 23 s = 1343 s and t _2p = 16 min 59 s = 1019 s. Therefore, over a time t _1p, N _1WC = 1.44 • 10 ¹⁵ 1.05 • 1.343 • 10 ³ WC / cm ² molecules is sprayed = 2.035 • 10 ¹⁸ WC / cm ² ≈ 2.04 • 10 ¹⁸ WC / cm ² ( we believe that together with each atomized carbon atom, the tungsten atom is also removed). Accordingly, over a time t _2p, N _2WC = 1.47 • 10 ¹⁸ • 1.05 • 1.019 WC / cm ² = 1.57 • 10 ¹⁸ WC / cm ^{2 is} sprayed. But the concentration of WC molecules is

During time t _p N _WC molecules WC / cm ^{2 were} removed. Therefore, the thickness of the sprayed layer d is

Let us now evaluate the real value of the cobalt concentration recorded by an X-ray diffractometer.

где n((x,τ) - концентрация атомов кобальта в приповерхностном слое;
x - расстояние, отсчитываемое от поверхности в глубину слоя;
τ - время испарения;
N - концентрация атомов кобальта в объеме;
D - коэффициент диффузии атомов кобальта;
ν = n(0,τ) = const - концентрация атомов кобальта на поверхности изделия из твердого сплава

где

характеристическая длина;
Ф(z) - функция ошибок.The profile of the concentration of cobalt atoms in sample No. 1, obtained by SIMS, corresponds to the case [9] of the final rate of evaporation of Co atoms from the surface. Suppose that the sintering process proceeds so that the density of Co atoms on the surface remains constant, i.e. diffusion of Co atoms to the surface compensates for the loss of Co atoms due to evaporation. Then, according to [9],

where n ((x, τ) is the concentration of cobalt atoms in the surface layer;
x is the distance measured from the surface into the depth of the layer;
τ is the evaporation time;
N is the concentration of cobalt atoms in the volume;
D is the diffusion coefficient of cobalt atoms;
ν = n (0, τ) = const is the concentration of cobalt atoms on the surface of the hard alloy product

Where

characteristic length;
Φ (z) is the error function.

Analyzing the distribution profile of Co atoms obtained by the SIMS method, in sample No. 1 we found, firstly, that ν = 2.3 • 10 ^-3 N and, secondly, that L = 0.267 μm, i.e., on this depth xz = 1. Therefore, the maximum value of z, which coincides with the depth of the layer analyzed in sample No. 1 by X-rays, is Z _a = 14.1 (see Table 2, where X _a = 3.76 μm for g _x = 0 , 95).

Заметим, что физический смысл интеграла в (7) - поверхностная концентрация - количество частиц на единицу поверхности с размерностью см^-2.So, if the concentration of cobalt near the surface of sample N 1 of T15K6 hard alloy and in its volume coincided and equaled N = const, then

Note that the physical meaning of the integral in (7) is the surface concentration - the number of particles per unit surface with a dimension of cm ^-2 .

где Ф^*(z) = 1 - Ф(z) (9)
Пользуясь приложением 2 монографии [10], в котором изложены свойства функции ошибок и родственных ей функций, получаем, что

при выбранных значениях Z_a не зависит от Z_a с точностью до бесконечно малых высших порядков и равен 0,5642.In fact

where Φ ^* (z) = 1 - Φ (z) (9)
Using Appendix 2 of the monograph [10], which sets out the properties of the error function and related functions, we obtain

at the chosen values of Z _a does not depend on Z _a up to infinitely small higher orders and is equal to 0.5642.

Итак, для z_a = 14,1 интеграл (10) равен 13,537 NL, а отношение

Поэтому мы полагаем, что при исследовании образца N 1, изготовленного из твердого сплава Т15К6, рентгеновским дифрактометром он регистрировал не значение концентрации кобальта в объеме, равное 5,21 мас.%, а меньшую величину, равную 0,961 5,21 = 5,00 мас.%.Hence

So, for z _a = 14.1, integral (10) is 13.537 NL, and the ratio

Therefore, we believe that when examining sample No. 1 made of T15K6 hard alloy with an X-ray diffractometer, he recorded not a value of cobalt concentration in the volume equal to 5.21 wt.%, But a smaller value equal to 0.961 5.21 = 5.00 wt. .%.

 Let us now evaluate the cobalt concentration recorded by an X-ray diffractometer in sample No. 2 from a T15K6 hard alloy (see Fig. 2).

Let us assume that in the range 0.33 μm – 3.76 μm greater than the interval 0–0.33 μm studied by SIMS, the cobalt concentration is constant and equal to n ₀ (n ₀ = 2 • 10 ⁴ pulses / sec in units of FIG. . 2). This statement is by no means groundless, as evidenced by the data of FIG. 4 (see below). For comparison with Fig. 1, we use the same notation: we again introduce the value z, which is 1 for a length equal to L = 0.267 μm. Then the point x = 0.33 μm corresponds to z = 1.24, the interval 0.33 - 3.76 μm Δz = 14.1-1.24 = 12.86. Therefore, the surface concentration of cobalt atoms in the range Δz is 12.86 • n ₀ L.

В интервале x = 0,138 мкм - 0,33 мкм (или z = 0,516 - 1,24) поверхностная концентрация кобальта равна

Итак, поверхностная концентрация кобальта, измеренная рентгеновским дифрактометром в образце N 2, равна:
L(12,86n₀ + 1,032n₀ + 1,06n₀ = 14,952n₀L
Выше показано, что эта же величина в образце N 1 равна 13,537 NL. Величина N, рассчитанная нами по профилю фиг. 1, равна N = 1,275•10⁵. Таким образом, отношение

равно

Итак, в этой серии опытов рентгеновский дифрактометр "не замечал" в образце N 2 из твердого сплава Т15К6 концентрацию кобальта, равную

Обратимся теперь к анализу профилей W, C и Cо в образце из твердого сплава ВК3М (фиг. 3 и 4). В данном случае энергия ионов кислорода составляла 8,1 кэВ. Ионный ток равнялся 654 нА (фиг. 3) и 548 нА (фиг. 4). Площади облучаемой ионами и анализируемой поверхностей не изменялись по сравнению с образцами 1 и 2 и равнялись, соответственно 6,25•10^-4 см² и 6,4•10^-7 см². Плотность ионного тока составляла: j₃ = 6,54•10^-3 /6,25 А/см² и j₄ = 5,48•10^-3/6,25 А/см². Количества ионов O $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ , падающих в 1 с на единицу поверхности, равнялись

Положим, как и ранее, что коэффициент распыления составляет S = 1,05 WC/O $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ . Время распыления равнялось: t_3р = 7 мин 21 с = 441 с и t_4р = 23 мин 34 с = 1414 с. Следовательно, за время t_3р распылится N_3WC = 6,54•10¹⁵•1,05•441 = 3,03•10¹⁸ молекул WC/см², а за время t_4р - N_4WC = 5,48•10¹⁵•1,05•1414 = 8,14•10¹⁸ WC/см².Let us now consider the interval investigated by the SIMS method: x = 0 - 0.33 μm or z = 0 - 1.24. We approximate the cobalt profile in this interval by a piecewise linear function x. In the range x = 0 - 0.138 μm (or z = 0 - 0.516), the surface concentration of cobalt is

In the range x = 0.138 μm - 0.33 μm (or z = 0.516 - 1.24), the surface concentration of cobalt is

So, the surface concentration of cobalt, measured by x-ray diffractometer in sample No. 2, is equal to:
L (12.86n ₀ + 1.032n ₀ + 1.06n ₀ = 14.952n ₀ L
It was shown above that the same value in sample No. 1 is 13.537 NL. The value N calculated by us according to the profile of FIG. 1 is equal to N = 1.275 • 10 ⁵ . Thus, the ratio

equally

So, in this series of experiments, the X-ray diffractometer “did not notice” a cobalt concentration equal to T15K6 in sample N 2 from the T15K6 hard alloy

We now turn to the analysis of the profiles of W, C, and Co in a sample of VK3M carbide (Figs. 3 and 4). In this case, the energy of oxygen ions was 8.1 keV. The ion current was 654 nA (Fig. 3) and 548 nA (Fig. 4). The areas irradiated by ions and the analyzed surfaces did not change compared to samples 1 and 2 and were equal, respectively, to 6.25 • 10 ^-4 cm ² and 6.4 • 10 ^-7 cm ² . The ion current density was: j ₃ = 6.54 • 10 ^-3 / 6.25 A / cm ² and j ₄ = 5.48 • 10 ^-3 / 6.25 A / cm ² . The number of O ions $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ falling in 1 s per unit surface were

Assume, as before, that the atomization coefficient is S = 1.05 WC / O $\genfrac{}{}{0ex}{}{\text{+}}{\text{2}}$ . The spraying time was: t _3p = 7 min 21 s = 441 s and t _4p = 23 min 34 s = 1414 s. Consequently, during the time t _3p Spray N _3WC = 6,54 • ^{15 October} • 1,05 • 441 = 3,03 • ^{18 October} molecules WC / cm ² and a time t _4p - N _4WC = 5,48 • ^{15 October} • 1.05 • 1414 = 8.14 • 10 ¹⁸ WC / cm ² .

Как видно из фиг. 3 и 4, профили кобальта на них отличаются между собой лишь толщиной распыленного слоя. Рассмотрим далее только более глубокий профиль кобальта, изображенный на фиг. 4. Аппроксимируем реальный ход профиля ломаной линии, для чего разобьем его на 11 участков. Элементарный расчет, который мы не приводим в описании, показывает, что суммарная площадь ограниченная ломаной, осью абсцисс и ординатами, проходящими через начало и конец профиля, составляет

При расчете мы вновь положили, что z = 1 соответствует L = 0,267 мкм, а n₀ = 2•10⁴ импульсов/с. Экстраполируя профиль на большую глубину до точки z_a = 10,7 (x_a = 2,86 мкм) и проводя аналогичные расчеты, получаем S₁₂ = 5,875n₀L. Итак, для образца 3 поверхностная концентрация равна

Сопоставим теперь концентрации, измеренные рентгеновским дифрактометром, в образцах 2 и 3. Напомним, что в образце 2, S = 14,952n₀L для Δz = 14,1. Положим, что для Δz = 10,7

По оси ординат на фиг. 1-4 отложены величины, имеющие размерность - количество импульсов за секунду. Чтобы правильно сопоставлять данные фиг. 2 и фиг. 4, надо отнести их к количеству распыленного вещества за 1 секунду. На фиг. 2 за 1 с распылялось 0,33 мкм : 1019 с = 3,24

а на фиг. 4 1,69 мкм : 1414 с = 11,94

Поэтому одна и та же величина n₀ = 2•10⁴ импульсов/с соответствует на фиг. 2 3,24

анализируемого слоя, а на фиг. 4 11,94

Итак, истинная концентрация Co в образце N 3 была в 11,94/3,24 = 3,7 раза меньше, чем в образце N 2. Поэтому величина

мас.%
должна быть уменьшена в 3,7 раза. Она составит 0,344 мас.% ≈ 0,3 мас.%.The thickness of the sprayed layer is

As can be seen from FIG. 3 and 4, the cobalt profiles on them differ only in the thickness of the sprayed layer. Further, we consider only the deeper cobalt profile shown in FIG. 4. We approximate the real course of the broken line profile, for which we divide it into 11 sections. An elementary calculation, which we do not give in the description, shows that the total area bounded by the broken line, abscissa, and ordinates passing through the beginning and end of the profile is

In the calculation, we again assumed that z = 1 corresponds to L = 0.267 μm, and n ₀ = 2 • 10 ⁴ pulses / s. Extrapolating the profile to a great depth to the point z _a = 10.7 (x _a = 2.86 μm) and performing similar calculations, we obtain S ₁₂ = 5.875n ₀ L. So, for sample 3, the surface concentration is

Now we compare the concentrations measured by the X-ray diffractometer in samples 2 and 3. Recall that in sample 2, S = 14.952n ₀ L for Δz = 14.1. Assume that for Δz = 10.7

The y-axis in FIG. Figures 1–4 show the quantities having the dimension — the number of pulses per second. In order to correctly match the data of FIG. 2 and FIG. 4, it is necessary to attribute them to the amount of atomized substance in 1 second. In FIG. 2 for 1 s sprayed 0.33 μm: 1019 s = 3.24

and in FIG. 4 1.69 μm: 1414 s = 11.94

Therefore, the same value n ₀ = 2 • 10 ⁴ pulses / s corresponds to FIG. 2 3.24

the analyzed layer, and in FIG. 4 11.94

So, the true concentration of Co in sample N 3 was 11.94 / 3.24 = 3.7 times less than in sample N 2. Therefore, the value

wt.%
should be reduced by 3.7 times. It will be 0.344 wt.% ≈ 0.3 wt.%.

 So, the cobalt concentration recorded by an X-ray diffractometer in sample No. 3 is 0.344 wt.% ≈ 0.3 wt.%. This value is taken by us as a threshold for achieving a positive effect when irradiating carbide products with ionizing radiation.

 Thus, the above experiments and estimated calculations allow us to choose as threshold: the concentration of metallic cobalt is not less than 0.3 wt. % and the thickness of the surface layer in which it is located, not less than 2.0 microns.

 Examples of achieving a positive effect - increasing the wear resistance and service life of the working parts of the cutters - carbide cutting inserts - are given below. It must be emphasized that X-ray studies of the content of cobalt metal in carbide cutting inserts, referred to in these examples, were carried out on the same diffractometer and in the same mode as the studies of the content of cobalt in the VK3M carbide. Therefore, the above conclusions about the threshold value of the concentration of cobalt, determined by him, are fully applicable to the data presented in the following examples.

 Example 1. Cutting inserts made of hard alloy MC 111 containing 9.5 wt. % of cobalt and subjected to radiation treatment was investigated by X-ray diffractometry and by laboratory tests for wear resistance at the Moscow plant of hard alloys (MKTS) and production tests for service life at the Lyubertsy production association "Plant named after Ukhtomsky." In all studied cutting inserts, X-ray measurements recorded a high concentration of cobalt metal.

 Laboratory tests were performed on a 1 M 63 machine under the following conditions: the material to be processed is steel 50, cutting mode: cutting speed v = 220 m / min, feed s = 0.20 mm / rev, cutting depth t = 1.0 mm. The maximum value of the resistance coefficient after irradiation with γ-quanta was 4.5, and after irradiation with α-particles it was 5.0.

 Production tests were carried out in workshop No. 21 on a model 473-4 hydrocopy machine. The workpiece is КРН03604, the workpiece material is 45G2 steel. Cutting mode: cutting speed v = 70 m / min, speed n = 400 rpm, feed s = 0.53 mm / rev, cutting depth t = 2.5 mm. The maximum value of the coefficient of resistance after irradiation with protons was 1.8; after irradiation with α-particles - 2.2; after irradiation with γ-rays 3.1 - 5.2.

 Example 2. Cutting inserts made of hard alloy MS 321, containing 6 wt.% Cobalt and irradiated with γ-quanta, were investigated by X-ray diffractometry and by conducting production tests for the service life at AOOT "VMP Chernyshev MMP". The tests were carried out when processing the part "Cheek" N 16110892 of steel 18 x 2H4A in the workshop N 5 in two operations.

 In operation N 020 (“turning”), the sole was grooved with an allowance of 2 mm. The tests were performed on a CNC lathe model SPR 16 NC. Tested 4-sided non-rotatable carbide inserts with mechanical fastening 2008 - 1865 grade MS 321-1865. Cutting modes: cutting speed v = 229 m / min, speed n = 900 rpm, feed s = 0.05 mm / rev, cutting depth: at 1 transition t = 3.5 mm, at 2 transition t = 2 , 0 mm, cooling - emulsion. Tests have shown: the resistance of plates without irradiation (serial) is 10 - 15 parts per face, the resistance of plates after irradiation was 55 - 60 parts per face. So, the minimum value of the coefficient of resistance is equal to 3.7; the average value is 4.6; the maximum value is 6.0.

 In operation N 025 ("turning"), a groove of the shank and a groove of the inner end of the cheek were performed. The tests were carried out on a CNC lathe model 16K20 T1. We tested 3-sided non-rotatable carbide inserts with mechanical fastening 2008-0388 of the brand MS 321-261. Cutting modes: cutting speed: at 1 transition v = 92 m / min, at 2 transition v = 189 m / min; number of revolutions: at 1 transition n = 1400 rpm, at 2 transition n = 900 rpm; feed: at 1 transition s = 0.2 mm / rev, at 2 transition s = 0.05 mm / rev; cutting depth t = 2.5 mm, cooling - emulsion. Tests have shown: the resistance of plates without irradiation (serial) is 10 parts per face, the resistance of plates after irradiation was 40 parts per face. So, the value of the resistance coefficient was 4.0.

 To confirm the results obtained, production tests of an industrial batch (100 pieces) of cutting inserts of each standard size were carried out under the same conditions. The tests confirmed the data above, but revealed a new pattern. In cases where x-ray measurements of the plates before γ-irradiation confidently detected the presence of cobalt metal in them, after γ-irradiation the resistance of tetrahedral plates amounted to 55 parts per face, the resistance of trihedral plates was 42 parts per face. In the same cases when X-ray measurements indicated the absence of cobalt metal in the surface layer of the plates, γ-radiation worsened the resistance of the plates: it amounted to only 4-5 parts per face. Thus, it was shown that only plates with a high content of metallic cobalt in the near-surface layer should be exposed to γ-radiation.

The device is made as follows:
1. Flat working carbide parts of the device are alloyed with cobalt using one of the following well-known methods: by ion implantation followed by stationary or pulsed photon annealing, sputtering (for example, electron-beam) cobalt in vacuum, followed by acceleration, cathode sputtering followed by acceleration .

 2. Working carbide parts of a complex shape device (non-flat) are alloyed with cobalt using one of the following known methods: ion-plasma spraying followed by acceleration, galvanic deposition followed by acceleration.

 3. Working carbide parts of a device of any shape are also alloyed with cobalt using one of the following methods, some of which are known for choosing stationary sintering modes, pulsed sintering, and sintering of a sintered product in vacuum.

 The role of cobalt metal is shown above by the example of cutting inserts made of hard alloys based on tungsten monocarbide with a cobalt bond. However, due to the fact that the physical and mechanical properties of cobalt do not change in other hard alloys and in combination with other ferromagnetic bonds (iron, nickel), these bonds can also be used in the proposed device.

Sources of information
1. Gurevich Yu.G., Narva V.K. Carbide steel. - M .: Metallurgy, 1989 .-- 25 p.

 2. Tretyakov V.I. Fundamentals of metal science and technology for the production of sintered hard alloys. - M .: Metallurgy, 1976 .-- S. 96-113.

 3. Tretyakov V.I. Fundamentals of metal science and technology for the production of sintered hard alloys. - M .: Metallurgy, 1976. - S. 125-205 (prototype).

 4. Mirkin L.I. Handbook of X-ray diffraction analysis of polycrystals. - M.: GIFFL. - 1961. - 84 p.

 5. Blokhin M. A. Physics of X-rays. - M.: Gostekhizdat, 1953.- 456 p.

 6. Dashman S. Scientific foundations of vacuum technology. - M.: IL, 1950 .-- 696 p.

 7. Nesmeyanov A. N. The vapor pressure of chemical elements. - M.: Publishing House of the USSR Academy of Sciences, 1961. - 396 p.

 8. Mouth I. Chemical spraying // Spraying solids by ion bombardment. Vol. II. - M .: Mir, 1986. - S. 134-204.

 9. The effect of evaporation of a volatile component on the electrical properties of CdSb / L.I. Anatychuk, V.M. Kondratenko, O.Ya. Luste, I.T. Havrunyak // Inorganic materials. - 1972. - T. VIII, N 4. - S. 653-658.

 10. Karslow G., Jaeger D. Thermal conductivity of solids. - M.: Nauka, 1964. - 488 p.

Claims (1)

 A device for machining solid materials, which is a solid body, the working part of which is made of a hard alloy with a ferromagnetic binder, characterized in that the ferromagnetic binder - metallic cobalt and solid solutions based on it - is introduced into the surface layer of the working part of the body, and the concentration of metallic cobalt is at least 0.3 wt.%, and the layer thickness is at least 2.0 microns.

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