CN103203664B - A kind of endoporus finishing method of selective laser melting Prototyping Metal Parts - Google Patents

Abstract

The invention provides a method for polishing the inner hole of a metal part formed by selective laser melting. The method for polishing the inner hole of a metal part formed by selective laser melting is by using SLM technology to manufacture a metal part containing an inner hole. Correspondingly forming the ultrasonic vibrating rod, after the metal parts are formed, continue to form the vibrating rod mounting seat connected to the inner hole ultrasonic vibrating rod, and then connect the vibrating rod mounting seat to the transducer of the ultrasonic equipment, and then use ultrasonic vibration polishing ( Abrasives are added to assist); the invention saves the time for making ultrasonic polishing tools, can polish multiple inner holes at the same time, has low cost, high efficiency, good adaptability to holes, and simple and accurate positioning.

Description

A method for inner hole polishing of metal parts formed by selective laser melting

technical field

The invention belongs to the field of laser processing, and in particular relates to an inner hole polishing method of a metal part formed by selective laser melting.

Background technique

Selective Laser Melting (SLM) technology is a technology that utilizes the metal powder to be completely melted under the heat of the laser beam, and then realize the metallurgical cladding and forming of solid metal through heat dissipation and cooling. SLM formed parts have a wide range of applications, such as tools and molds in the mechanical field (micro-manufactured parts, micro-devices, tool inserts, molds), bio-implanted parts or replacement parts (teeth, vertebrae) in the biomedical field, and in the electronics field. Heat dissipation devices, ultra-light structural parts in the aerospace field, functionally gradient composite material parts, etc. A typical process of using SLM technology to directly form metal parts is: according to the layered slice information of the 3D CAD model of the formed part, the scanning system controls the laser beam to act on the powder in the area to be formed. The piston descends a layer thickness distance; then the powder feeding system delivers a certain amount of powder, and the powder spreading system spreads a layer of powder with a certain thickness to deposit on the formed layer. Then, repeat the above two forming processes until all the slice layers of all 3D CAD models are scanned. In this way, the three-dimensional CAD model is directly formed into metal parts by layer-by-layer accumulation. Finally, the piston is pushed up to remove excess metal powder, and the part is taken out from the forming equipment. At this point, the entire process of SLM metal powder directly forming metal parts is over.

As far as the current technical level is concerned, the surface roughness of the inner hole of metal parts directly formed by SLM technology is generally above 20 μm (depending on process factors such as laser scanning parameters and powder particle size). However, the surface quality of parts has a great influence on the performance, life and reliability of parts, and has a great relationship with the performance and life of the whole product. Polishing is to polish the surface of parts and products. Its main purpose is to remove the processing traces of the previous process, change the surface roughness of the parts, and obtain a bright and smooth surface for the product. Due to the different materials and shapes of the processing objects, the requirements for surface roughness are also different. Therefore, the requirements for polishing technology are complex and changeable. At present, the polishing methods widely used in China include CNC rolling tool polishing, jet polishing, electric spark polishing and ultrasonic polishing.

Ultrasonic polishing is a method of using ultrasonic vibration on the end face of the polishing tool to force the abrasive suspension to machine the surface of hard and brittle materials; The micro-convex part is micro-machined to achieve the purpose of polishing. Ultrasonic polishing is characterized by high polishing efficiency. If the polishing time is long enough, the surface roughness can reach 0.03 μm, but it requires a polishing tool (vibrator) that matches the wall of the polished hole. At present, during ultrasonic polishing, for inner holes of different sizes and shapes, it is necessary to use machining methods to make polishing tools separately, which is time-consuming, laborious, and costly, prolonging the processing time of parts and limiting its large-scale industrial application; at the same time The vibrating rod needs to be assembled with the general ultrasonic transducer components and inserted into the inner hole of the metal part accurately. For metal parts with a large number of inner holes, the vibrating rod mounting plate must be made by machining alone or once Only one hole can be polished and polished in turn, so it is difficult to achieve accurate clamping and positioning of the vibrating rod, and the polishing efficiency is very low.

Contents of the invention

The present invention aims at the deficiencies of the above-mentioned prior art, and provides a method for polishing the inner hole of a metal part formed by selective laser melting; the method for polishing the inner hole of a metal part formed by selective laser melting At the same time as the metal parts, the ultrasonic vibrating rod is correspondingly formed in the inner hole. After the metal parts are formed, the vibrating rod mounting seat connected to the inner hole ultrasonic vibrating rod is continued to be formed, and the vibrating rod mounting seat is subsequently connected to the transducer of the ultrasonic equipment. , can be polished by ultrasonic vibration (adding abrasives to assist); the invention saves the time for making ultrasonic polishing tools, can polish multiple inner holes at the same time, has low cost, high efficiency, good adaptability to holes, and simple and accurate positioning .

The present invention is achieved through the following technical solutions:

A method for polishing the inner hole of a metal part formed by selective laser melting, characterized in that it comprises the following steps:

(1) According to the CAD model of the metal part, design an ultrasonic vibrating rod that is compatible with the inner hole on the metal part;

(2) According to the shape type, size, quantity and position distribution of the ultrasonic vibrating rod designed in step (1), design the vibrating rod mounting seat connected with the ultrasonic vibrating rod;

(3) According to the processing principle of SLM technology, metal parts, ultrasonic vibrating rods and vibrating rod mounts are manufactured in layers.

(4) Connect the ultrasonic polishing equipment, set the polishing process parameters, add abrasives, and perform polishing to obtain the polished inner hole.

Preferably, the number of ultrasonic vibrating rods in step (1) is one or more, and the ultrasonic vibrating rods are in one-to-one correspondence with the inner holes on the metal parts.

Preferably, the number of ultrasonic vibrating rods in step (1) is one or more, and multiple inner holes with the same shape and size on the metal part correspond to the same ultrasonic vibrating rod.

Preferably, the vibrating rod mounting base and the vibrating rod in step (2) are integrally structured.

Preferably, the vibrating rod mounting base and the vibrating rod in step (2) are of a split structure; the vibrating rod mounting base is provided with vibrating rod mounting holes corresponding to all inner holes on the metal parts.

Preferably, in step (4), if the number of ultrasonic vibrating rods is equal to the number of inner holes on the metal parts, the metal parts, all ultrasonic vibrating rods, vibrating rod mounts and ultrasonic equipment are connected for polishing; if the ultrasonic vibrating rods If the number of holes is less than the number of inner holes on the metal parts, first install all the ultrasonic vibrating rods to the corresponding positions of the vibrating rod mounting seats, connect the metal parts, ultrasonic vibrating rods, vibrating rod mounting seats and ultrasonic equipment, and perform a polishing process ; After that, select the next unpolished inner hole, install the ultrasonic vibrating rod corresponding to the inner hole on the corresponding position of the vibrating rod mounting seat, and polish it; so repeated, until all the inner holes are polished.

The inner hole polishing method of selective laser melting forming metal parts according to the present invention has the following beneficial effects:

1. Compared with the ordinary ultrasonic polishing method, the present invention also manufactures the vibrating rod and the vibrating rod mounting seat for ultrasonic polishing while manufacturing metal parts. (Vibrating rod and vibrating rod mounting seat) shortens the polishing cycle, reduces the polishing cost, and greatly reduces the manufacturing time and cost of the inner hole.

2. Compared with the ordinary ultrasonic polishing method, the present invention can conveniently manufacture corresponding ultrasonic polishing vibrating rods for all the inner holes of metal parts. The ultrasonic mounting seat and vibrating rod can be designed and processed in an integrated manner. The relative position, shape and size are accurate, and there is no assembly process, thereby eliminating the problem of positioning errors; and it is suitable for various sizes of inner holes, and there is no special requirement for materials.

Description of drawings

Fig. 1 is the flow chart of the inner hole polishing method of selective laser melting forming metal part of the present invention;

Fig. 2 is a relationship diagram among the metal parts, the vibrating rod and the vibrating rod mounting seat in the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

The invention provides a method for polishing the inner hole of a metal part formed by selective laser melting, as shown in Figures 1 and 2, comprising the following steps:

(1) According to the CAD model of the metal part 1, design the ultrasonic vibrating rod 2 adapted to the inner hole on the metal part 1; the design method is the same as that of the existing ultrasonic vibrating rod, requiring the shape and size of the ultrasonic vibrating rod 2 It should be adapted to the shape and size of the inner hole of the metal part 1 for the ultrasonic polishing process.

The number of the ultrasonic vibrating rod 2 can be multiple, and its quantity and position distribution are determined according to the number and position distribution of the inner holes on the metal part 1, and only one ultrasonic vibrating rod can be designed for multiple inner holes of the same shape type and size. Vibrator 2.

(2) According to the shape type, size, quantity and position distribution of the ultrasonic vibrating rod 2 designed in step (1), design the vibrating rod mount 3 connected to the ultrasonic vibrating rod 2;

For the situation that the number and position distribution of the ultrasonic vibrating rod 2 are consistent with the number and position distribution of the inner holes on the metal part 1, the vibrating rod mounting seat 3 and the vibrating rod 2 can be designed as an integrated structure, or can be designed as a separate structure. Assembly structure. For the case where only one ultrasonic vibrating rod 2 is designed for multiple inner holes of the same shape type and size, the vibrating rod mounting base 3 must be designed to correspond to all inner holes on the metal part 1. Ultrasonic vibrating rod 2 matches the vibrating rod installation hole. The vibrating rod mounting base 3 also needs to be designed with a connecting part 4 matching with the ultrasonic equipment, so as to be connected with the transducer of the ultrasonic equipment during polishing.

(3) According to the processing principle of SLM technology, the metal part 1 , the ultrasonic vibrating rod 2 and the vibrating rod mounting seat 3 are manufactured by stacking. This is the prior art, and will not be repeated in the present invention.

(4) Connect the ultrasonic polishing equipment, set the polishing process parameters, add the abrasive material 5, and perform polishing to obtain the polished inner hole.

For the situation that the number and position distribution of the ultrasonic vibrating rod 2 are consistent with the number and position distribution of the inner holes on the metal part 1, it is only necessary to connect the metal part 1, the ultrasonic vibrating rod 2, the vibrating rod mounting seat 3 and the ultrasonic equipment, and carry out The corresponding polishing process is sufficient;

For the situation that only one ultrasonic vibrating rod 2 is designed for multiple inner holes of the same shape type and size, first select a certain unpolished inner hole among the multiple inner holes of the same shape type and size, and apply the ultrasonic wave Install the vibrating rod 2 to the corresponding position of the vibrating rod mounting seat 3, then connect the metal parts 1, the ultrasonic vibrating rod 2 and the vibrating rod mounting seat 3 and the ultrasonic equipment, and perform a polishing process; Among multiple inner holes of different sizes, select the next unpolished inner hole, install the ultrasonic vibrating rod 2 on the corresponding position of the vibrating rod mounting seat 3, and install the metal part 1, the ultrasonic vibrating rod 2 and the vibrating rod After the seat 3 and the ultrasonic equipment are connected, another polishing process is carried out; this is repeated until all inner holes are polished.

Claims (6)

1. an endoporus finishing method for selective laser melting Prototyping Metal Parts, is characterized in that, comprise the following steps:

(1) according to the cad model of metal parts, the ultrasound wave vibrating bar that design adapts with the endoporus on metal parts;

(2) according to the shape type of the ultrasound wave vibrating bar of design in step (1), size, quantity and position distribution, the vibrating head mount pad be connected with ultrasound wave vibrating bar is designed;

(3) according to SLM technology process principle, layered manufacturing goes out metal parts, ultrasound wave vibrating bar and vibrating head mount pad;

(4) connect ultrasonic polissoir, glossing parameter is set, adds abrasive material, carry out polishing, obtain the endoporus after polishing.

2. the endoporus finishing method of selective laser melting Prototyping Metal Parts according to claim 1, it is characterized in that, the quantity of ultrasound wave vibrating bar is one or more in step (1), the endoporus one_to_one corresponding on described ultrasound wave vibrating bar and metal parts.

3. the endoporus finishing method of selective laser melting Prototyping Metal Parts according to claim 1, it is characterized in that, in step (1), the quantity of ultrasound wave vibrating bar is one or more, the corresponding same ultrasound wave vibrating bar of multiple endoporus that on metal parts, geomery is identical.

4. the endoporus finishing method of selective laser melting Prototyping Metal Parts according to claim 1, is characterized in that, described in step (2), vibrating head mount pad and vibrating head are structure as a whole.

5. the endoporus finishing method of selective laser melting Prototyping Metal Parts according to claim 1, is characterized in that, described in step (2), vibrating head mount pad and vibrating head are split-type structural; On described vibrating head mount pad, be provided with vibrating head installing hole with the correspondence position of all endoporus on metal parts.

6. the endoporus finishing method of selective laser melting Prototyping Metal Parts according to claim 1, it is characterized in that, in step (4), if the quantity of ultrasound wave vibrating bar is equal with the quantity of endoporus on metal parts, metal parts, all ultrasound wave vibrating bars are connected with vibrating head mount pad and ultrasonic equipment, carry out polishing; If the quantity of ultrasound wave vibrating bar is less than the quantity of endoporus on metal parts, then first all ultrasound wave vibrating bars are installed on the correspondence position of vibrating head mount pad, metal parts, ultrasound wave vibrating bar are connected with vibrating head mount pad and ultrasonic equipment, carry out stock removal polishing process; Afterwards, more selected next unpolished endoporus, the ultrasound wave vibrating bar corresponding with this endoporus is installed on the correspondence position of vibrating head mount pad, carries out polishing; So repeatedly carry out, until the equal polishing of all endoporus is complete.