CN110360948B - Laser cladding layer and molten pool shape characterization method - Google Patents

Abstract

The invention discloses a laser cladding layer and a molten pool shape characterization method, belongs to the technical field of laser cladding remanufacturing, and relates to a laser cladding layer and a molten pool shape characterization method. Firstly, cutting a cladded substrate sample along a direction vertical to a cladding layer scanning path by using a wire cutting machine; then, grinding the cut matrix sample on abrasive paper with different grain sizes according to a metallographic sample preparation method in the order from small grain size to large grain size; then, taking a picture of the polished substrate sample with super depth of field; then, drawing the appearance profiles of the cladding layer and the molten pool in the super-depth-of-field photo by utilizing the arc extensions with different curvature radiuses, and recording the curvature radius of each section of arc; and finally, measuring the width and the height of the whole profile and an included angle between the cladding layer and the molten pool. The method can rapidly and accurately represent the appearance profiles of the cladding layer and the molten pool.

Description

A method for characterizing the morphology of laser cladding layer and molten pool

technical field

The invention belongs to the technical field of laser cladding and remanufacturing, and relates to a method for characterizing the morphology of a laser cladding layer and a molten pool.

Background technique

Laser cladding technology is an advanced remanufacturing technology. It is widely used in the field of rapid prototyping and repair of parts due to its advantages of small heat-affected zone, small workpiece deformation and high bonding strength. However, in the process of rapid prototyping and repair of parts, the process parameters of laser cladding have a crucial impact on the quality of forming and repairing, and the geometry of the cladding layer affects the overlap ratio and Z-axis of laser cladding. Process parameters such as lifting amount have a direct impact, so the characterization of laser cladding layer and molten pool morphology plays a crucial role in the rapid prototyping and repair quality of parts. For the characterization of the geometry of the laser cladding layer, the patent "A method for automatically controlling the geometry of the laser-induction composite cladding coating" (CN103060798 U) by Dai Xiaoqin et al. A method to characterize the geometry of cladding coatings. For the characterization of the geometry of the laser molten pool, Sun Jun et al.'s patent "A method for determining the morphology of the electroslag remelting metal molten pool" (CN105675513 A) provides a method to characterize the geometry of the molten pool by the depth of the metal molten pool morphological method. However, neither of these two methods can fully characterize the topography of the cladding layer and the molten pool, especially when the laser cladding of the inclined base plane is performed, due to the influence of gravity on the tension of the cladding layer and the molten pool, the cladding is caused. The topography of the cladding layer and the molten pool is no longer symmetrical, so the original characterization method of the cladding layer and the molten pool cannot express the influence of gravity on the topography of the cladding layer and the molten pool. The impact of rapid prototyping and repair quality of parts. Therefore, in order to more fully characterize the cladding layer and the topography of the molten pool, so as to realize the purpose of rapid prototyping and repair quality of the inclined base surface by gravity, it is necessary to invent a laser cladding layer and the topography of the molten pool. Characterization method.

SUMMARY OF THE INVENTION

The present invention overcomes the defects of the prior art, especially when the laser cladding of the inclined base surface is performed, due to the influence of gravity on the tension of the cladding layer and the molten pool, the topography and contour of the cladding layer and the molten pool are no longer any longer. Therefore, the existing characterization methods of cladding layer and molten pool morphology cannot express the influence of gravity on the cladding layer and molten pool morphology profile, and thus cannot study the effect of gravity on the rapid prototyping and repair quality of parts; especially It is the characterization of the cladding layer and the morphology of the molten pool on the surface of the inclined substrate. A method for characterizing the morphology of a laser cladding layer and a molten pool is invented. The method firstly uses a wire cutting machine to cut the cladding substrate sample. Then, the cut substrate samples were polished on sandpapers of different particle sizes according to the method of metallographic sample preparation; the polished substrate samples were then photographed with super depth of field. Then, arcs with different curvature radii are used to rub the topography of the cladding layer and the molten pool in the super-depth-of-field photos. Finally, the width and height of the entire topographical profile and the angle between the cladding layer and the molten pool are measured. In this way, the purpose of fully characterizing the cladding layer and the shape and profile of the molten pool can be achieved, and the purpose of studying the effect of gravity on the rapid prototyping and repairing quality of the inclined base surface can be achieved.

The technical scheme adopted in the present invention is a method for characterizing the morphology of a laser cladding layer and a molten pool, which is characterized in that the method firstly uses a wire cutting machine to cut the cladding substrate sample along the direction of the vertical scanning path of the cladding layer. Cut; then grind the cut substrate samples on sandpapers of different particle sizes according to the method of metallographic sample preparation, in order of particle size number from small to large; then take the polished substrate samples for super depth of field photography ; Next, use arcs with different curvature radii to draw the topography of the cladding layer and the molten pool in the super depth of field photo, and record the curvature radius of each arc; finally measure the width, height and cladding layer of the entire topographic profile. and the angle between the molten pool. The specific steps of the method are as follows:

Step 1 Cut the cladding matrix sample

Use the wire cutting machine to cut the cladding substrate sample along the direction of the vertical scanning path of the cladding layer;

Step 2 Grinding the cut substrate sample

Grind the cut substrate samples on sandpapers of different particle sizes according to the method of metallographic sample preparation, in the order of particle size numbers from small to large;

Step 3 Take photos with super depth of field

Take photos of the polished substrate sample with a super-depth-of-field instrument;

Step 4 Draw the outline of the cladding layer and the molten pool

Use arcs with different curvature radii to draw the topography of the cladding layer and molten pool in the super-depth of field photos, and record the curvature radius of each arc;

Step 5: Measure the topography of the cladding layer and the molten pool

Measure the width, height and angle between the cladding layer and the molten pool of the entire topographic outline drawn by the super-depth of field photo.

The beneficial effect of the present invention is to provide a characterization method for the cladding layer on the surface of the inclined substrate and the topography profile of the molten pool. The cladding layer and the morphological profile of the molten pool on the surface of the inclined substrate can be characterized by the curvature radii of different arcs, the width and height of the entire morphological profile, and the angle between the cladding layer and the molten pool, which can not only fully characterize the cladding layer It can also achieve the purpose of studying the effect of gravity on the rapid prototyping and repair quality of inclined base surfaces. The method is simple and direct, and realizes the rapid and accurate characterization of the cladding layer and the morphology of the molten pool.

Description of drawings

Fig. 1 is a schematic diagram of the position of the inclined substrate by laser cladding, Fig. 2 is a schematic diagram of the position of the substrate to be cut,

Figure 3 is a super-depth-of-field photograph of the substrate sample.

Fig. 4 is a schematic diagram of the arc numbering of the topography of the topography of the cladding layer and the molten pool. Among them, the outline of the cladding layer is enclosed by the No. 1 arc, the No. 2 arc, the No. 3 arc and the No. 4 arc, and the outline of the molten pool is enclosed by the No. 5 arc, the No. 6 arc, the No. 7 arc, the No. 8 arc Arc No. 9, Arc No. 9, Arc No. 10, and Arc No. 11 are enclosed.

Figure 5 is a schematic diagram of the overall morphology of the cladding layer and the molten pool. Among them, W-width, h-height, α-cladding layer and the left angle of the molten pool, β-cladding layer and the right angle of the molten pool.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and technical solutions.

The base material used in this example is 17CrNiMo6, and the cladding layer material is Ni60. The tilt angle of the substrate is 60°, the laser power is 2000W, the scanning speed is 0.003m/s, and the powder feeding rate is 20r/min. The specific steps of the method are as follows:

Step 1 Cut the cladding matrix sample

Use the wire cutting machine to cut the cladding substrate sample along the direction of the vertical scanning path of the cladding layer, that is, cut along the position marked with the cutting line in Figure 2;

Step 2 Grinding the cut substrate sample

Grind one of the cut substrate samples on sandpapers with particle sizes of 80, 120, 400, 800, 1500, 2000 and 2500 according to the method of metallographic sample preparation, and then polish the polished substrate samples. to polish;

Step 3 Take photos with super depth of field

Use the ultra-depth-of-field instrument to take pictures of the polished substrate sample, as shown in Figure 3;

Step 4 Draw the outline of the cladding layer and the molten pool

The topography of the cladding layer and molten pool in the super-depth-of-field photo shown in Figure 3 is drawn using arcs with different curvature radii, and the curvature radius of each arc is recorded. As shown in Figure 4, the contour of the cladding layer can be enveloped by four arcs: No. 1 arc, No. 2 arc, No. 3 arc and No. 4 arc, among which the curvature radii of No. 1 arc and No. 4 arc It is 27.8mm, the radius of curvature of the No. 2 arc is 13.9mm, and the radius of curvature of the No. 3 arc is 4.7mm; The arc, the No. 10 arc and the No. 11 arc are enveloped in seven segments, of which the radius of curvature of the No. 5 arc is 0.4mm, the radius of curvature of the No. 6 arc is 7.5mm, the radius of curvature of the No. 7 arc is 1.5mm, The radius of curvature of the No. 8 arc is 5mm, the radius of curvature of the No. 9 arc is 4.2mm, the radius of curvature of the No. 10 arc is 0.4mm, and the radius of curvature of the No. 11 arc is 5mm;

Step 5: Measure the topography of the cladding layer and the molten pool

Measure the width, height and angle between the cladding layer and the molten pool of the entire topographic outline drawn by the super-depth of field photo. As shown in Figure 5, the width W of the entire topography profile is 5.9 mm, the height h is 1.9 mm, and the angle α between the cladding layer and the molten pool is 42° and β is 41°.

This method realizes the rapid and accurate characterization of the cladding layer and molten pool topography.

Claims (1)

1. A laser cladding layer and molten pool shape characterization method is characterized in that a linear cutting machine is used for cutting a cladded substrate sample along a direction vertical to a cladding layer scanning path; then, grinding the cut matrix sample on abrasive paper with different grain sizes according to a metallographic sample preparation method in the order from small grain size to large grain size; then, taking a picture of the polished substrate sample with super depth of field; then, drawing the appearance profiles of the cladding layer and the molten pool in the super-depth-of-field photo by utilizing the arc extensions with different curvature radiuses, and recording the curvature radius of each section of arc; and finally, measuring the width and the height of the whole profile and an included angle between the cladding layer and a molten pool, wherein the method comprises the following specific steps:

step 1, cutting a cladded matrix sample

Cutting the clad matrix sample along the direction vertical to the cladding layer scanning path by using a wire cutting machine;

step 2, polishing the cut substrate sample

Grinding the cut matrix sample on abrasive paper with different grain sizes according to a metallographic sample preparation method in the order from small grain size to large grain size;

step 3, ultra-depth-of-field photographing

Photographing the polished substrate sample by using a super depth-of-field instrument;

step 4, drawing the shape and contour of the cladding layer and the molten pool

Drawing the appearance profiles of a cladding layer and a molten pool in the super-depth-of-field photo by utilizing the circular arcs with different curvature radiuses, and recording the curvature radius of each section of circular arc;

step 5, measuring the shape and the profile of the cladding layer and the molten pool

And measuring the width and the height of the whole shape profile developed by the super-depth-of-field photo and the included angle between the cladding layer and the molten pool.

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