CN108372342A - A kind of increasing material manufacturing method of high-strength alusil alloy - Google Patents

Abstract

The invention discloses a high-strength aluminum-silicon alloy additive manufacturing method, comprising the following steps: A. substrate cleaning; B. CMT additive manufacturing: using a CMT welding machine and a welding robot with inert gas protection to perform single-pass welding; C. Hammering between layers: Hammering with a hammering device after each weld is completed, until it is greater than or equal to the set deformation; D. Repeat steps B and C until the additive manufacturing of high-strength aluminum-silicon alloy is completed. The present invention mainly utilizes the preparation technology of CMT, together with an online hammer strengthening device, so that the pores of the weldment after hammering are reduced, the columnar crystals are broken, and the preferred orientation disappears, the tensile strength reaches 180MPa, and the elongation exceeds 25%.

Description

A kind of additive manufacturing method of high-strength aluminum-silicon alloy

technical field

The invention belongs to the technical field of additive manufacturing, in particular to an additive manufacturing method based on a high-strength aluminum-silicon alloy.

Background technique

The additive manufacturing method is different from the traditional equal material or subtractive manufacturing technology. It can directly form complex structural parts, and no mold is needed during the forming process. Its production efficiency is not affected by the complexity of the workpiece, while the electric arc additive manufacturing technology forms High efficiency, up to Kg/h, very suitable for high-efficiency additive manufacturing.

CMT (Cold Metal Transition Technology) is a kind of arc additive manufacturing technology. It is an additive manufacturing technology with flexible manufacturing form, relatively low cost, high forming efficiency and small heat input. Precise control can realize rapid prototyping of complex structural parts.

Aluminum alloy is widely used in aerospace because of its light weight, good plasticity and toughness, and it occupies an important position in the national economy. In order to improve the strength of aluminum alloy, Si, Mg, Cu and other alloying elements are added to industrial pure aluminum. The strengthening phase of aluminum alloy includes: CuAl ₂ , Mg ₂ Si, Al ₂ CuMg, etc. These strengthening phases are relatively rare in aluminum. High solubility, which decreases significantly with decreasing temperature. Therefore, follow-up heat treatment strengthening is required. For large structural parts, on the one hand, the cost is high, it is difficult to find a suitable heat treatment device, and there will be a certain degree of deformation after treatment. On the other hand, the cost will change after adding alloy elements. high.

The process of additive manufacturing is layer-by-layer printing, which is different from traditional subtractive or equal-material manufacturing. Due to the temperature gradient, the prepared materials have a certain texture, resulting in anisotropic materials, which limits the use of materials in some occasions. application.

Contents of the invention

The purpose of the present invention is to provide a method for additive manufacturing of high-strength aluminum-silicon alloys to solve the following technical problems in the prior art: (1) The metal material for additive manufacturing has the characteristics of anisotropy, which limits its application; (2) The traditional casting method for preparing aluminum alloys requires high cost and complex heat treatment process when adding strengthening elements Si, Cu or Mg to improve the strength of aluminum alloys. The method of the invention can improve the strength of the aluminum-silicon alloy manufactured by additive manufacturing, and the anisotropy caused by the preferred orientation disappears.

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for additive manufacturing of high-strength aluminum-silicon alloys, comprising the following steps:

A. Substrate cleaning;

B. CMT additive manufacturing: use CMT welding machine and welding robot with inert gas protection for single-pass welding;

C. Hammering between layers: Hammering with a hammering device after each weld is completed, until it is greater than or equal to the set deformation amount;

D. Repeat steps B and C until the additive manufacturing of high-strength aluminum-silicon alloy is completed.

Further, in step A, the flat substrate with the same composition as the additive manufacturing raw material is cleaned with acetone and alcohol until clean.

Further, the metal wire used for single-pass welding is 4043 aluminum-silicon alloy, and the weight percentage of the metal wire is Si: 4.5-6.0%, Fe: 0.8%, Cu: 0.30%, Mn: 0.05%, Mg: 0.05% , Zn: 0.10%, Ti: 0.20%, and the balance is aluminum.

Further, the diameter of the metal wire is 0.8 to 1.6mm.

Further, during single-pass welding, the metal wire is fed to the CMT excitation component at a speed of 3 to 7m/min, and the CMT additive manufacturing program is executed by scanning along the workpiece at a speed of 300 to 700mm/min.

Further, the set deformation amount is 50%.

Further, during single pass welding in step B, the welding speed is 300-700mm/min, and the welding current is 100A.

Further, step D finally obtains a high-strength aluminum-silicon alloy with a tensile strength greater than or equal to 180Mpa and a Vickers hardness greater than or equal to 62HV.

Further, step D finally obtains the high-strength aluminum-silicon alloy with an elongation rate exceeding 25%.

Compared with the prior art, the present invention has the following beneficial effects:

a. The present invention mainly utilizes the new preparation method of CMT, which can realize the rapid prototyping of aluminum alloy blanks, achieve fast and flexible manufacture of parts with special shapes, and has the characteristics of simple method, low cost and flexible production.

b. The aluminum-silicon alloy prepared by this method can make the Si phase present fine equiaxed crystals, eliminating the coarse dendrite structure obtained by direct welding.

c. Using this method, an aluminum-silicon alloy with a tensile strength of about 180 MPa and an elongation of more than 25% can be obtained.

Description of drawings

Figure 1 is a comparison diagram of aluminum-silicon alloy pores before and after hammering; Figure 1(a) is a front view of hammering, and Figure 1(b) is a rear view of hammering;

Figure 2 is a comparative diagram of the longitudinal structure of Al-Si alloy after CMT welding and the structure after hammering; among them, Figure 2(a) is the longitudinal structure of Al-Si alloy before hammering; Figure 2(b) is the Al-Si alloy after hammering vertical organization.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments, which are explanations of the present invention rather than limitations.

Example

An additive manufacturing method for high-strength aluminum-silicon alloy, the welding raw material is aluminum alloy welding wire with a diameter of 0.8-1.6 mm. The specific process is as follows:

A. First clean the aluminum alloy substrate with the same composition as the welding wire with acetone and alcohol in sequence;

B. Install the welding wire, turn on the Ar shielding gas, and check that the wire feeding and cooling systems are not faulty; the welding wire is 4043 aluminum-silicon alloy, and the mass percentage of the metal wire is Si: 4.5-6.0%, Fe: 0.8%, Cu: 0.30 %, Mn: 0.05%, Mg: 0.05%, Zn: 0.10%, Ti: 0.20%, the balance is aluminum;

C. After step B, use CMT equipment to weld according to the corresponding parameters:

a. Set the TCP point and write the corresponding welding program;

b. Welding process parameters are: welding speed 300-700mm/min, welding current about 100A, and waiting time for each pass is about 10s. During single-pass welding, the metal wire is fed to the CMT excitation component at a speed of 3 to 7m/min, and the CMT additive welding program is executed by scanning along the workpiece at a speed of 300 to 700mm/min.

D. Hammering: Use the air hammer strengthening device to repeatedly hammer the single-pass sample after welding until the deformation exceeds 50%.

E. Repeat steps C and D until the desired height of the sample is obtained.

It can be seen from Figure 1 that the porosity of the aluminum-silicon alloy weldment after hammering is significantly reduced, which is beneficial to the improvement of the fatigue life of the material.

It can be seen from Figure 2 that the longitudinal columnar grains of the aluminum-silicon alloy weldment after hammering are broken, and the grains are obviously refined. Due to the deformation and breakage of the columnar grains, the problem of obvious preferred orientation of the additive manufacturing weldment is eliminated.

The hammering device may be an air hammer, electromagnetic hammer, hydraulic hammer or other hammering devices capable of deforming the aluminum-silicon alloy.

After the single-pass welding is completed, after the formed weld bead drops to the temperature that can be hammered, adjust the center of the hammer head to coincide with the center of the weld bead, and perform hammering layer by layer according to the established path; the deformation is controlled at 50% or above; After setting the amount of deformation, repeat the process of welding and hammering until the predetermined thickness is reached.

It can be seen from Table 1 that the tensile strength of the aluminum-silicon weldment after hammering is significantly improved, which proves that online hammering strengthening is an effective means to improve the strength of aluminum-silicon alloys:

Table 1 Strength comparison of Al-Si alloy before and after hammering

sample Raw Al-Si Alloy Weldments Al-Si alloy weldment after hammering Tensile strength (MPa) 153 MPa 180MPa Vickers Hardness (HV) 43HV 62HV

Claims (9)

1. a kind of increasing material manufacturing method of high-strength alusil alloy, which is characterized in that include the following steps：

A. base-plate cleaning；

B.CMT increasing material manufacturings：Using CMT welding machines and welding robot with inert gas shielding, single track welding is carried out；

C. interlayer hammers：It is often soldered and is just hammered together with hammering device, until more than or equal to setting deflection；

D. B, step C are recycled, until completing the increasing material manufacturing of high-strength alusil alloy.

2. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that will in step A Ingredient planarizing substrate acetone identical with increasing material manufacturing raw material and alcohol are cleaned to clean.

3. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that single track welds institute It is 4043 alusil alloys with metal wire material, it is Si which, which forms mass percent,：4.5~6.0%, Fe：0.8%, Cu： 0.30%, Mn：0.05%, Mg：0.05%, Zn：0.10%, Ti:0.20%, surplus is aluminium.

4. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 2, which is characterized in that metal wire material A diameter of 0.8 to 1.6mm.

5. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that single track welds When, metal wire material is supplied to CMT driver units with 3 to 7m/min speed, is swept along workpiece with 300 to 700mm/min speed It retouches and executes CMT increasing material manufacturing programs.

6. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that the setting becomes Shape amount is 50%.

7. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that single in step B When road welds, 300~700mm/min of speed of welding, welding current 100A.

8. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that step D is final The tensile strength for obtaining high-strength alusil alloy is greater than or equal to 180Mpa, and Vickers hardness is greater than or equal to 62HV.

9. a kind of increasing material manufacturing method of high-strength alusil alloy according to claim 1, which is characterized in that step D is final It is more than 25% to obtain high-strength alusil alloy elongation percentage.