CN102978628A - Method for carrying out anatonosis by adopting laser plasma impact wave in chemical heat treatment process - Google Patents

Abstract

The invention relates to a method for carrying out anatonosis by adopting laser plasma impact waves in a chemical heat treatment process. According to the method, induction to generate plasma impact waves are generated by induction with high-power short-pulse laser, act on materials and are combined with chemical heat treatment, thereby improving the surface property of metal materials and members and enhancing the oxidation resistance, abrasion resistance and corrosion resistance of the metal material and the members, wherein the chemical heat treatment can be alumetizing, carburization, nitridation, aluminum-chromium penetration and the like. The method disclosed by the invention has the beneficial effects that the temperature of the chemical heat treatment in order to obtain identical penetration layer depth, the temperature of the chemical heat treatment can be obviously reduced, and the treatment time is shortened, thereby reducing the deformation of workpieces.

Description

Adopt the method for laser-(produced)plasma shockwave anatonosis in Process of Chemical Thermal Treatment

Technical field

The invention belongs to surface engineering technology and field of laser processing, relate in particular to a kind of method that adopts the anatonosis of laser-(produced)plasma shockwave in Process of Chemical Thermal Treatment.

Background technology

Thermo-chemical treatment can be used for improving the quality of products, and prolonged mechanical product work-ing life, for example, carburizing can be used for the drive disk assemblies such as gear; Metallic cementation can significantly improve anti-oxidant, the corrosion resistance nature of part, guarantees normal operation at high temperature and extends its work-ing life.In general, heat energy is used in thermo-chemical treatment, and required diffusion temperature is higher or diffusion time is long, energy consumption is large.Mechanical energy aided diffusion (ZL01107820.0) technology utilizes penetration enhancer and impinging particle in the cylinder of process furnace, workpiece surface to be impacted, change the heat transfer by conduction mode of thermo-chemical treatment into the particle transmission of heat by convection, increase particle Contact chance, and under the effect of mechanical energy and heat energy, particle kinetic energy activates workpiece surface dot matrix atom, forms the room, thereby realizing helping oozes, ultimate principle of the present invention is all different from the method with implementation process, is a kind of new seepage increasing method.

Summary of the invention

The technical problem that solves

For fear of the deficiencies in the prior art part, the present invention proposes a kind of method that adopts the anatonosis of laser-(produced)plasma shockwave in Process of Chemical Thermal Treatment, reduce the thermo-chemical treatment time, improve quality layer, and form the tissue of stable performance at material or component surface, thereby significantly improve quality layer.

Technical scheme

A kind of method that adopts the anatonosis of laser-(produced)plasma shockwave in Process of Chemical Thermal Treatment is characterized in that step is as follows:

Step 1: on motor system, adopt laser radiation absorbing on supercoat the test specimen clamping, supercoat absorbing laser energy is induced the generation plasma stock wave, acts on workpiece surface; Described optical maser wavelength is 1064/532nm, and pulse width is nanosecond order, laser power density 3-8GW/cm ², hot spot overlapping rate 50-75%;

Step 2: the workpiece after laser blast wave is processed, adopt aluminising, nitriding or carburization process to carry out thermo-chemical treatment.

Beneficial effect

A kind of method that adopts the anatonosis of laser-(produced)plasma shockwave in Process of Chemical Thermal Treatment that the present invention proposes, utilize superpower, short-pulse laser to induce and produce plasma stock wave to material effects, and combine with thermo-chemical treatment, thereby improve metallic substance and component surface performance, improve that it is anti-oxidant, resistance to wear, corrosion resistant method, thermo-chemical treatment can be aluminising, carburizing, nitriding and aluminising chromium etc.Compare with the conventional chemical heat treating method:

1, the method adopts superpower, short-pulse laser to induce and produces the high pressure plasma shockwave, act on material surface, utilize the mechanics effect of shockwave that material is processed, produce high density dislocation, grain refining at material surface, even produce nanocrystalline, thereby reduce diffusion activation energy, increase diffusion admittance, improve diffuser efficiency, form stable infiltration layer.

2, under the effect of high-pressure shocking wave, high strain rate dynamic response occurs in material, makes that the material surface dislocation increases, grain refining even produces nanocrystalline.The increase of dislocation desity and crystal boundary, for the atomic diffusion in the subsequent chemistry heat treatment process provides passage, the diffusion activation energy of atom reduces, and is conducive to diffusion and the reaction of element.

Description of drawings

Fig. 1: the conventional carburizing SEM figure of 12CrNi3A steel;

Fig. 2: carburizing SEM figure after 12CrNi3A steel laser-(produced)plasma shock wave;

In figure: 1, compound layer, 2, the cementation zone of carbide-containing, 3, cementation zone.

Embodiment

Now in conjunction with the embodiments, the invention will be further described for accompanying drawing:

The laser parameter of the embodiment of the present invention requires: optical maser wavelength is 1064/532nm, and pulse width is nanosecond order, laser power density 3-8GW/cm ², hot spot overlapping rate 50-75%, spot size and shape are according to the Workpiece structure feature selection.Chemical heat treatment process can be aluminising, carburizing, nitriding or aluminising chromium etc.

The technical solution adopted in the present invention step is:

(a) with the test specimen clamping on motor system, adopt high power density 3-8GW/cm ², ns level short pulse laser radiation absorbing on protective layer, coating absorbing laser energy, and induce the generation plasma stock wave acts on workpiece surface; Plasma stock wave is according to the pending zone of effect, certain path, and the area overlapping rate between hot spot is 50-75%; Under induced with laser plasma shock wave, high strain rate dynamic response occurs in the workpiece surface material, produces high density dislocation, and makes grain refining;

(b) to the workpiece after the laser blast wave processing, carry out corresponding thermo-chemical treatment (as aluminising, nitriding or carburizing etc.).

In concrete enforcement: 12CrNi3A converted steel commonly used is carried out the anatonosis of laser-(produced)plasma shockwave process, the concrete technology step is:

(a) optical maser wavelength 1064nm is set, pulsewidth 20ns, power density is 3.2GW/cm ²(laser energy 8J, light spot shape is circular, spot diameter 4mm), hot spot overlapping rate 60%.

(b) adopt adhesive tape for absorbing supercoat, stick on 12CrNi3A steel surface;

The workpiece that (c) will be pasted with absorber coatings installs on motor system, adopts superpower, short-pulse laser to carry out shock treatment to 12CrNi3A steel surface.

(d) with the 12CrNi3A steel after shock wave, carry out carburizing treatment, obtain one deck cementation zone on its surface, concrete technology is: adopt pit carburizing furnace, under the atmosphere of 880 ℃ ± 10 ℃ temperature and toluene medium dripping type, be incubated 3-5 hour.

By above example, can see that effect of the present invention is: at the plasma stock wave treatment zone of gear, because super-refinement crystal grain and the high density dislocation tissue on top layer has very high free energy, and defective sharply increases, for the diffusion of atom provides passage, the depth of penetration that forms is deepened, diffusion layer organization fine and close (as shown in Figure 2), with compare than common process carburizing (as shown in Figure 1), the surface carbonation thing is evenly distributed, tiny, be conducive to the raising of surface abrasion resistance, tissue, the performance of base material do not have to change substantially simultaneously.Therefore, in order to obtain identical depth of penetration, can significantly reduce the thermo-chemical treatment temperature, shorten the treatment time, thereby can reduce the distortion of workpiece.Carry out cut resistance test on the SJ-Tribometer wear tester, test conditions is as follows: load 14.7 newton, linear velocity 100mm/s, 45000 weeks of running.After the anatonosis of laser-(produced)plasma shockwave is processed, the specific wear rate of test specimen has reduced more than 40%.

Claims (1)

1. method that adopts the anatonosis of laser-(produced)plasma shockwave in Process of Chemical Thermal Treatment is characterized in that step is as follows:

Step 1: on motor system, adopt laser radiation absorbing on supercoat the test specimen clamping, supercoat absorbing laser energy is induced the generation plasma stock wave, acts on workpiece surface; Described optical maser wavelength is 1064/532nm, and pulse width is nanosecond order, laser power density 3-8GW/cm ², hot spot overlapping rate 50-75%;

Step 2: the workpiece after laser blast wave is processed, adopt aluminising, nitriding or carburization process to carry out thermo-chemical treatment.

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