Auxiliary gas is right 5A06 aluminium alloy Nd: The influence of YAGLaser Cutting quality

Use Nd of solid of high power pulse: The board of 5A06 aluminium alloy with YAG large to 4mm laser undertakes cut experiments, discuss the effect of auxiliary gas Ar, nitrogen, oxygen to Laser Cutting quality. Through diffraction of ray of measuring instrument of electron microscope of optical microscope, scanning, surface roughness, X appearance analysis is cut seam appearance of the form appearance that reachs section, surface roughness, substance and microstructure. 1 foreword aluminium reachs the wide application of aluminium alloy. Make the cut method of aluminium alloy forward nicety, efficient, quick way develops, but fiber-optic conductive Nd: YAGLaser Cutting technology becomes the most appropriate means. Use CO2 laser the craft of material of successive cut aluminium alloy and mechanism already had document story domestic and internationally, use Nd of solid of high power pulse: The material such as titanium of YAGLaser Cutting other, nickel, stainless steel also has research report, but Nd: The report of YAGLaser Cutting aluminium alloy still is belonged to rarely seen. Nd: The wavelengh of YAG laser is the 1/10 of CO2 laser, aluminium alloy rises greatly to the absorptivity of laser of this wave band, can improve cut quality thereby. Laser Cutting quality suffers the effect of many sided element, auxiliary gas is among them a crucial factor. Above all, it is exclusive with the material that is contacted by cut data phase, affecting the stand or fall of Laser Cutting quality directly; Next, auxiliary gas is easy bad news is tasted in cut process, deciding the cost of Laser Cutting. Research assists gas to have fair theoretical value not only to the influence of material of Laser Cutting aluminium alloy, and can provide certain referenced basis for actual application. The article uses Nd of solid of high power pulse: Aluminium alloy of 5A06 of YAG laser cut, from cut seam width, cut seam appearance of the form appearance that reachs section, surface roughness, substance, microstructure to analyse research to assist aeriform Ar, N2, O2 to be opposite the influence of Laser Cutting quality. 2 tests data and method 2.

The aluminium alloy of 4mm thick 5A06 that 1 test data chooses extruding, rolling to machine board for experiment object, if its chemistry composition expresses 1 to show. Cut parts with auxiliary gas is purity for 99.

The Ar of 99 ％ , N2, O2, with stimulate coaxial of beam of light to output. The chemical composition that expresses 1 5A06 aluminium alloy (％ ) 2.

Test of 2 experiments means uses the pulse solid Nd that equipment is rated power 500W: YAG laser, wavelengh 1.

06 μ M. If the craft parameter of Laser Cutting5A06 aluminium alloy expresses 2 to show. Use Ar, N2, O2 to make auxiliary gas respectively, in other craft parameter changeless circumstance falls, research assists aeriform atmospheric pressure and sort to be opposite the influence of quality of Laser Cutting5A06 aluminium alloy. Express 2 Nd: The craft parameter of YAGLaser Cutting5A06 aluminium alloy controls the sample after cut metallographic test block, the hydrofluoric acid that uses 4 ％ corrodes 5 ～ 7s, its are measured to cut below CMM-20 optical microscope seam width, observe microcosmic organization; Observe appearance of tangent plane form with electron microscope of JEOL JSM-6700 scanning; Measure the surface roughness of tangent plane with measuring instrument of surface roughness of Mahr Perthometer M2; With diffraction of Y-2000 X ray appearance analyses the substance appearance of tangent plane. 3 tests result is analysed 3.

The influence of atmospheric pressure of 1 auxiliary gas assists gas to basically be used at blowing off from cut area slaggy cut in order to form seam. Laser Cutting is the throughput that enters cut to assisting the main demand of air current big, rate is high, so that have enough momentum,give area of melt material eject. Graph 1 it is to cut the relation curve that seams width to change along with auxiliary atmospheric pressure, can see choose why to be planted no matter gas makes auxiliary gas, as baric accretion, cut seam width span not quite, its are very small to cutting the influence that seams width. Graph 1 cut the curve that seams width to change along with auxiliary gas pressure to express 3 it is auxiliary atmospheric pressure the effect that measures to hanging broken bits, atmospheric pressure is 0.

5Mpa or 0.

When 6Mpa, hang broken bits very few. In this experiment, as baric accretion, gas sheds momentum to increase, cuttings pick-up ability rises, the quantity that hang broken bits is little; But if atmospheric pressure spends plenary session,make aeriform efflux appears disorder phenomenon. Form irregular to cut then seam, bring about cut seam quality addle, choose suitable aeriform pressure talent to get relatively good cut quality consequently. The influence that expresses 3 auxiliary atmospheric pressure to be measured to hanging broken bits 3.

The influence of sort of 2 auxiliary gas 3.

2.

1 cut seam reach analysis of appearance of tangent plane form to use different auxiliary gas, of Laser Cutting5A06 aluminium alloy cut seam openly difference not quite, all narrow fine flat, but the reverse side has bigger different, all have different rate hang broken bits, the metal that hanging broken bits is melt is assisted gas from cut seam when be being blown, adhere to of overleaf, if pursue,2 are shown. When use Ar makes auxiliary gas, cut seam the reverse side not to have oxidation almost; When use N2, cut seam rear and slight oxidation; When use O2, cut seam the reverse side relatively before both oxidation is serious, hang broken bits more; But 3 person hang broken bits, grind gently with sand paper drop namely. The reverse side of aluminium alloy of graph 2 Laser Cutting5A06 measures aluminium alloy of Laser Cutting5A06 of 3 kinds of auxiliary gas respectively cut seam width and verticality, if the watch is shown 4 times, make auxiliary gas verticality with O2 among them highest. Ar, N2 makes auxiliary gas, the I level that cuts seamed verticality to achieve GB/Z18462-2001 accuracy class, o2 makes auxiliary gas, the 0 level that cut seamed verticality to achieve GB/Z18462-2001 accuracy class. Those who express aluminium alloy of 4 Laser Cutting5A06 cut seam width to pursue 3 it is to use J to plant respectively the tangent plane graph of aluminium alloy of 5A06 of auxiliary gas cut, (D)(e)(f) is respectively (the SEM enlarge of A)(b)(c) pane area. Can see from inside the graph, 3 person tangent plane is apart from on exterior 1/4 department is slicker, bottom is coarser, and the cut that role entrusts after the area that has different rate is moire. Because pulse energy is higher,the ripple of upside is, make a metal direct vaporization, each ripple is the trace of the vaporization that pulse of a laser makes, because laser pulse energy is reduced somewhat,lower ripple is in, the metal happens to fuse and be poured out of along with high-pressured gas only, be down the lag as a result of fused speed more, what role entrusts after forming is moire, when fused metal cannot be blown completely, bottom is formed hang broken bits. Tangent plane SEM magnifies the graph sees, when Ar makes auxiliary gas, ripple is more shallow; N2 makes the take second place when auxiliary gas; The ripple when O2 makes auxiliary gas is mixed and disorderly, 3 person hang broken bits to estimate ordinal increase. 3 person surface roughness is ordinal for 2.

870 μ M, 3.

554 μ M, 7.

The 0 level that 974 μ M reachs GB/Z18462-2001 accuracy class. The appearance of tangent plane form of aluminium alloy of graph 3 Laser Cutting5A06 3.

2.

The tangent plane of aluminium alloy of the Laser Cutting5A06 when analysis of appearance of substance of 2 tangent plane parts to make auxiliary gas to Ar, N2, O2 undertakes X ray diffraction is analysed, graph 4 it is XRD graph. Al3Mg2 of the compound between the metal that 5A06 aluminium alloy is Mg to be formed in the solid solution of Al and Mg and Al in the photograph composition below room temperature; When Ar makes auxiliary gas, tangent plane basically is Al and Al3Mg2, because Ar is inert gase, do not produce reaction with other material; When N2 makes auxiliary gas, tangent plane basically is Al, Al3Mg2 and AlN, because N element falls to generate AlN with Al reaction in high temperature; And when O2 makes auxiliary gas. Tangent plane basically is Al, Al3Mg2 and Al2O3, because O element is below high temperature,with Al reaction generates Al2O3. 3.

2.

Aluminium alloy of Laser Cutting5A06 of analysis of organization of 3 cut area is process of a hot-working. When laser action arrives on material, much heat makes material fused, vaporization, at the same time as coaxial as laser auxiliary gas takes away much quantity of heat, action of the rest quantity of heat arrives on base material and make the micromechanism of interface produces a change. As the shift that stimulates beam of light, because assist the action that aeriform action and base material heat conduct, the material that contacts with laser gets fast refrigeration. The X ray of tangent plane of aluminium alloy of graph 4 Laser Cutting5A06 analyses a scheme 5 it is to use Ar, N2, O2 respectively, when making auxiliary gas, the cut area of Laser Cutting5A06 aluminium alloy metallograph. Can see from inside the graph, 3 person there all is layer of a remelting on tangent plane, because laser illuminate arrives when aluminium alloy,the formation of remelting layer is, interior of data of illuminate point point evaporates form hole, absorb a person to shoot energy of beam of light to make the aluminium alloy all round fuses quickly as boldface, high pressure assists gas to fuse one much the metal is blown, and the fused metal that another part has not enough time to be blown stays in tangent plane surface caky formed layer of a remelting, the pulse as a result of laser is additionally removed, in cut process, fused metal classics for many times caky formed layer of layer shape remelting. But 3 person remelting layer ply is different, when Ar makes auxiliary gas, remelting layer ply is 70 μ M; When N2 makes auxiliary gas, when remelting layer ply makes auxiliary gas for 100 μ M; O2, remelting layer ply is 200 μ M. (A) Ar makes auxiliary gas (B) N2 makes auxiliary gas (C) O2 makes aluminium alloy of 5 Laser Cutting5A06 of auxiliary gas graph cut seam all round when action of energy of golden phasor laser arrives on material of 5A06 aluminium alloy, make material fused or vaporization, make the micromechanism of interface produces a change, form heat to affect an area thereby (HAZ) O pursues 5 show, when Ar makes auxiliary gas, the width of HAZ is 90 μ M; When N2 makes auxiliary gas, the width of HAZ is 100 μ M; 02 when making auxiliary gas, base material and remelting change without apparent grain between the layer, HAZ is not apparent. Because Ar or N2 make auxiliary gas,this is when, al or AlN basically are respectively on tangent plane, the hot conductivity of these two kinds of material is taller, when laser energy action arrives on material of 5A06 aluminium alloy, because assist the action that gas and heat conduct, energy by deliver mother capable person very quickly to go up, form HAZ thereby; And when O2 makes auxiliary gas, al2O3 basically is on tangent plane, its thermal conductivity is poor, make quantity of heat basically is centered in remelting layer thereby, only a few quantity of heat conducts mother capable person, reason HAZ is not apparent. From the graph 5 in still can see, when making auxiliary gas rest with Ar, N2, O2 respectively, micro-crack all exists on tangent plane. Person crackle traceable remelting layer, because melt metal cooling rate is rapid,this is, tangent plane produces heat build-up stress easily, bring about crackle to form. Additional, the content of the hot tearing tendency of the aluminium alloy that 5xxx fastens and Mg is reduced relevant, when Laser Cutting of 5A06 aluminium alloy, the energy that stimulates beam of light is very high, those who cause Mg element burn caustic, make Mg content drops, cause crackle very easily on remelting layer so. Before both, the crackle of traceable remelting layer, expand HAZ, stop crack at mother capable person, because HAZ grain is bulky,this is make crackle easily patulous, and grain of mother capable person is lesser tenacity is bigger, block up of crackle patulous. Latter, because HAZ is not apparent, the crackle at remelting layer was cracked to expand in mother capable person 50 μ M stops to expand namely since. 3 kinds of gas make 4 conclusion Ar, N2, O2 aluminium alloy of 5A06 of auxiliary gas cut, cut seam the front all narrow fine flat, the reverse side hangs broken bits to estimate ordinal increase; Cut seam verticality to be respectively 0.

08mm, 0.

08mm and 0.

05mm; Tangent plane surface roughness is respectively 2.

870 μ M, 3.

554 μ M, 7.

974 μ M; The effect that assists aeriform pressure to seam width to cutting is not apparent. The photograph composition of matrix of 5A06 aluminium alloy is Al+Al3Mg2, ar makes aluminium alloy of auxiliary gas Laser Cutting5A06, tangent plane is formed without new look; And N2 makes auxiliary gas, new look AlN was formed on tangent plane; O2 makes auxiliary gas, al2O3 photograph appears on tangent plane. Laser Cutting5A06 aluminium alloy, tangent plane forms remelting layer, with Ar, N2, O2, make auxiliary gas, remelting layer ply is 70 μ M, 100 μ M, 200 μ M respectively; Tangent plane all is put in micro-crack; HAZ width is 90 μ respectively not M, 100 μ M, apparent. CNC Milling