Selective laser melting forming Inconel718 alloy and heat treatment method thereof

A technology of laser selective melting and heat treatment, which is applied in the direction of additive manufacturing, process efficiency improvement, additive processing, etc., can solve the problems of unfavorable Nb element release, reduction of precipitation strengthening phase, low solid solution temperature, etc., and achieve good comprehensiveness Effects of improving mechanical properties, room temperature yield strength, and room temperature tensile strength

Inactive Publication Date: 2020-07-03
SOUTH CHINA UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the forming characteristics of rapid cooling and rapid solidification of laser selective melting forming technology make Inconel718 alloy parts after forming generally have large local thermal stress, Nb element segregation causes a large amount of brittle Laves phase to precipitate, γ", γ', δ phase The precipitation is inhibited, and the boundary remelting zone of the melting channel is prone to defects such as microcracks. Through proper heat treatment, the defects of the formed sample can be improved to a certain extent.
[0008] At present, the post-treatment process of Inconel718 alloy formed by laser selective melting mostly follows the standard heat treatment scheme of traditional casting and forging, which cannot effectively solve the unique problems of laser selective melting and forming. Althoug

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  • Selective laser melting forming Inconel718 alloy and heat treatment method thereof
  • Selective laser melting forming Inconel718 alloy and heat treatment method thereof
  • Selective laser melting forming Inconel718 alloy and heat treatment method thereof

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Embodiment 1

[0034] The invention discloses a heat treatment method for improving the performance of Inconel718 alloy formed by laser selective melting, which can be realized through the following process steps:

[0035] Step (1): The Inconel718 sample formed by selective laser melting is subjected to high-temperature hot isostatic pressing heat treatment, and then air is quickly cooled to room temperature;

[0036] The specific process parameters of this step: the heat treatment temperature of hot isostatic pressing is 1050°C-1120°C, the pressure is 1400bar-1480bar, and the holding time is 90min-120min;

[0037] Process parameters of this embodiment: the temperature is 1080°C, the pressure is 1480 bar, and the holding time is 120 min.

[0038] Among them, the heating rate of the hot isostatic pressing equipment is 7°C / min to 8°C / min, and the pressure increase rate is 10bar / min to 11bar / min; the optimal process parameters are set as follows: the temperature increase rate is 8°C / min, The s...

Embodiment 2

[0046] This embodiment is the same as Embodiment 1 except for the following features.

[0047] During the heat treatment in step (2) and step (3), the heating rate of the furnace is the same, that is, 5°C / min to 6°C / min; both are preferably 6°C / min.

[0048] Combine below Figure 1 to Figure 3 , the Inconel718 alloy obtained in the above embodiments of the present invention and its performance improvement will be further described.

[0049] figure 1 It is a 2000 times enlarged microstructure diagram of the sample of the present invention before heat treatment.

[0050] figure 1 It shows the structure of the samples observed by scanning electron microscope after being ground and polished and corroded by corrosive solution. It can be seen that there are obvious overlapping boundaries in the alloy before heat treatment, and there are a large number of dendritic subgrain structures in the arc-shaped molten pool and on the overlapping boundaries, and the white precipitates betw...

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Abstract

The invention belongs to the fields of a metal additive manufacturing technology and a high-temperature alloy heat treatment technology, and particularly relates to a selective laser melting forming Inconel718 alloy and a heat treatment method thereof. The heat treatment method comprises the following process steps of (1) carrying out hot isostatic pressure heat treatment on a formed Inconel718 sample at 1080 DEG C; (2) carrying out solid solution heat treatment on the sample subjected to hot isostatic pressure at 980 DEG C; and (3) sequentially carrying out double-aging heat treatment on thesample subjected to solid solution at 720 DEG C and 620 DEG C. According to the heat treatment method, the high-temperature hot isostatic pressure heat treatment is added before the conventional solidsolution heat treatment, and meanwhile, the heat preservation time for solid solution and double-aging heat treatment is increased, so that a brittleness Laves phase and microscopic porosity existedin the selective laser melting forming Inconel718 alloy sample are eliminated, the precipitation of a strengthening phase is effectively promoted, the ductility of materials is retained to a greater degree while the material strength is remarkably improved, and a favorable comprehensive mechanical property is obtained.

Description

technical field [0001] The invention relates to the technical fields of metal additive manufacturing technology and high-temperature alloy heat treatment, in particular to a laser selective melting forming Inconel718 alloy and a heat treatment method thereof. Background technique [0002] Inconel718 alloy is an important material that can be applied under high temperature and high load. It is widely used in aerospace, nuclear industry and energy fields because of its good high temperature mechanical properties and excellent high temperature corrosion resistance and oxidation resistance. [0003] The Inconel718 alloy mainly uses the γ" (Ni3Nb) phase as the main strengthening phase, and the γ' (Ni3(Al, Ti, Nb)) phase and the δ (Ni3Nb) phase as the auxiliary strengthening phase. Using different forming methods and heat treatment processes, it can be obtained Inconel718 alloy parts with different microstructure and mechanical properties can meet the application standards in diff...

Claims

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Application Information

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IPC IPC(8): B22F3/24C22F1/10B22F3/105B33Y10/00B33Y80/00
CPCB22F3/24C22F1/10B33Y10/00B33Y80/00B22F2003/248B22F10/00B22F10/28B22F10/64Y02P10/25
Inventor 肖志瑜张荣班乐柳中强何文艺陈进
Owner SOUTH CHINA UNIV OF TECH
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