Cold Spray법으로 제조된 pure Cu와 Cu-Sn composite 코팅막의 특성
Characteristics of pure Cu and Cu-Sn composite coatings by cold spray process
- 주제(키워드) cold spray
- 발행기관 아주대학교 일반대학원
- 지도교수 고경현
- 발행년도 2012
- 학위수여년월 2012. 2
- 학위명 석사
- 학과 및 전공 일반대학원 재료공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000012387
- 본문언어 한국어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
본 연구에서는 cold spray process를 이용하여 pure Cu와 Cu-Sn composite을 Al 기판 위에 코팅하고 코팅효율, 경도 등의 코팅막 특성과 열처리 시 확산 거동을 분석하는 연구가 진행되었다. 코팅에 사용된 Cu powder는 총 3종류로 각각 Cu 1, 2, 3 powder라 명명하였다. Cu 1 powder는 55μm 급 dendritic type, Cu 2 powder는 50μm 급 dendritic type, Cu 3 powder는 12μm 급 spherical type의 powder이며, Sn powder는 65μm 급 irregular type powder 였다. 코팅은 de Laval type nozzle을 사용하여 진행되었으며, carrier gas는 compressed air를 사용하였다. gas 온도와 압력은 450℃～650℃, 2MPa로 결정되었다. IMC 형성을 위한 열처리는 Cu의 산화 방지를 위하여 질소 분위기에서 진행되었으며, 300℃, 4시간의 조건으로 결정되었다. powder의 상태에 따라 코팅막의 특성이 달라지므로 다양한 분석기기를 이용하여 powder에 대한 분석이 진행되었다. pure Cu powder의 코팅막은 powder shape이나 powder pretreatment에 따라 코팅 효율, 경도 등의 코팅 특성의 변화를 관찰할 수 있었다. 특히 powder pretreatment 조건에 따라 powder surface oxide 함량과 내부 응력 상태를 제어할 수 있었다. Cu-Sn composite 코팅막은 powder shape에 따라 코팅 mechanism이 달라지며 이에 따른 IMC 형성 거동에 차이를 보인다. feedstock ratio에 따라 matrix type을 제어할 수 있으며, matrix에 따른 확산 거동의 확연한 차이를 관찰할 수 있다.
more목차
차 례(Table of Contents)
본문차례(List of Text)
1. 서론 ………………………………………………………………………… 1
2. 이론 고찰 …………………………………………………………………… 2
2.1. Cold spray 역사와 동향 ……………………………………………… 2
2.2. Cold spray 코팅의 원리 ……………………………………………… 3
2.3. Cold spray 코팅의 원리 ……………………………………………… 8
3. 실험 방법 ………………………………………………………………… 10
3.1. 실험 재료 ……………………………………………………………… 11
3.2. 시편 제작 ……………………………………………………………… 16
3.3. 코팅막의 분석 ………………………………………………………… 19
3.3.1. Optical Microscopy(OM) 분석 ………………………………… 19
3.3.2. 코팅 효율(Deposition Efficiency) 분석 ………………………… 19
3.3.3. 경도 시험(Hardness Test) ……………………………………… 19
3.3.4. X-Ray Diffraction(XRD) 분석 ………………………………… 20
3.3.5. Energy Dispersive Spectroscopy(EDS) 분석 ………………… 20
3.3.6. Scanning Electron Microscopy(SEM) 분석 ………………… 20
3.3.7. X-ray photoelectron Spectroscopy(XPS) 분석 ……………… 20
3.3.8. Oxygen Determinator 분석 ……………………………………… 20
4. 결과 및 고찰 ……………………………………………………………… 22
4.1. powder pretreatment에 따른 pure Cu 코팅 ……………………… 22
4.1.1. 코팅막의 OM 분석 ………………………………………………… 23
4.1.2. 코팅효율과 코팅막의 경도 분석 ………………………………… 32
4.1.3. powder의 SEM과 PSA 분석 …………………………………… 39
4.1.4. powder의 XRD 분석 ……………………………………………… 44
4.1.5. powder의 Oxygen Determinator 분석 ………………………… 47
4.2. Cu powder shape에 따른 코팅 특성 ……………………………… 50
4.2.1. 코팅효율과 코팅막의 경도 분석 ………………………………… 50
4.2.2. 코팅막의 SEM 분석 ……………………………………………… 56
4.2.3. powder shape에 따른 pure Cu 코팅 mechanism …………… 58
4.3. Feedstock의 oxide chemistry에 따른 코팅 ……………………… 60
4.3.1. 코팅막의 OM 분석 ………………………………………………… 61
4.3.2. 코팅효율과 코팅막의 경도 측정 ………………………………… 63
4.3.3. powder의 XPS 분석 ……………………………………………… 68
4.3.4. Oxygen determinator 분석 ……………………………………… 72
4.4. Cu powder shape에 따른 Cu-Sn composite 코팅 ……………… 73
4.4.1. 코팅막의 OM 분석 ………………………………………………… 73
4.4.2. 코팅막의 XRD 분석 ……………………………………………… 79
4.4.3. 코팅막의 EDS 분석 ……………………………………………… 84
4.4.4. Cu powder shape에 따른 Cu-Sn composite 코팅 mechanism … 89
4.5. feedstock ratio에 따른 Cu-Sn composite 코팅 ………………… 91
4.5.1. 코팅막의 OM 분석 ………………………………………………… 91
4.5.2. 코팅막의 XRD 분석 ……………………………………………… 94
4.5.3. 코팅막의 EDS 분석 ……………………………………………… 96
4.5.4. feedstock ratio에 따른 Cu-Sn composite 코팅 mechanism … 101
5. 결론 ……………………………………………………………………… 103
참고문헌(Reference) ……………………………………………………… 106
그림차례(List of Figures)
Fig. 2-2-1 Influence of impact velocity and particle size on features of the interaction of the cold spray process …………………… 5
Fig. 2-2-2 Schematic diagram of the cold spray coating equipment … 6
Fig. 2-2-3 Coating mechanism of the cold spray process …………… 7
Fig. 3-1-1 SEM image of powder (a) Cu 1 powder (x500), (b) Cu 2 powder (x500), (c) Cu 3 powder (x2000), (d) Sn powder (x500) … 12
Fig. 3-1-2 Size distribution of powder (a) Cu 1 powder, (b) Cu 2 powder, (c) Cu 3 powder, (d) Sn powder ………………………… 14
Fig. 3-2-1 Phase diagram of Cu-Sn system ………………………… 17
Fig. 4-1-1 OM images of as-coated coatings using as-received Cu 1 powder (x500) ………………………………………………… 24
Fig. 4-1-2 OM images of as-coated coatings using (a) Air annealed (50℃ 1h), (b) Air annealed (100℃ 1h), (c) Air annealed (150℃ 1h), (d) Air annealed (200℃ 1h) Cu 1 powder (x500) …… 25
Fig. 4-1-3 OM images of as-coated coatings using (a) Air annealed (50℃ 6h), (b) Air annealed (100℃ 6h), (c) Air annealed (150℃ 6h), (d) Air annealed (200℃ 6h) Cu 1 powder (x500) …… 26
Fig. 4-1-4 OM images of as-coated coatings using (a) Vacuum annealed (50℃ 6h), (b) Vacuum annealed (100℃ 6h), (c) Vacuum annealed (150℃ 6h) Cu 1 powder (x500) ……………… 27
Fig. 4-1-5 OM images of as-coated coatings using as-received Cu 2 powder (x500) ………………………………………………… 28
Fig. 4-1-6 OM images of as-coated coatings using (a) Air annealed (50℃ 1h), (b) Air annealed (100℃ 1h), (c) Air annealed (150℃ 1h), (d) Air annealed (200℃ 1h) Cu 2 powder (x500) …… 29
Fig. 4-1-7 OM images of as-coated coatings using (a) Air annealed (50℃ 6h), (b) Air annealed (100℃ 6h), (c) Air annealed (150℃ 6h), (d) Air annealed (200℃ 6h) Cu 2 powder (x500) …… 30
Fig. 4-1-8 OM images of as-coated coatings using (a) Vacuum annealed (50℃ 6h), (b) Vacuum annealed (100℃ 6h), (c) Vacuum annealed (150℃ 6h) Cu 2 powder (x500) ……………… 31
Fig. 4-1-9 Deposition efficiency and hardness of as-coated coatings using as-received and (a) Air annealed (1h), (b) Air annealed (6h) Cu 1 powder ……………………………………………………… 35
Fig. 4-1-10 Deposition efficiency and hardness of as-coated coatings using as-received and (a) Vacuum annealed (1h), (b) Vacuum annealed (6h), (c) Vacuum annealed (12h) Cu 1 powder … 36
Fig. 4-1-11 Deposition efficiency and hardness of as-coated coatings using as-received and (a) Air annealed (1h), (b) Air annealed (6h) Cu 2 powder ……………………………………………………… 37
Fig. 4-1-12 Deposition efficiency and hardness of as-coated coatings using as-received and (a) Vacuum annealed (1h), (b) Vacuum annealed (6h), (c) Vacuum annealed (12h) Cu 2 powder … 38
Fig. 4-1-13 SEM image of annealed Cu 1 powder (a) Air annealed (100℃ 6h), (b) Air annealed (200℃ 6h), (c) Vacuum annealed (100℃ 1h), (d) Vacuum annealed (150℃ 6h) ………………………………… 40
Fig. 4-1-14 Size distribution of Cu 1 powder ………………………… 41
Fig. 4-1-15 SEM image of annealed Cu 2 powder (a) Air annealed (100℃ 6h), (b) Air annealed (200℃ 6h), (c) Vacuum annealed (100℃ 1h), (d) Vacuum annealed (150℃ 6h) ………………………………… 42
Fig. 4-1-16 Size distribution of Cu 2 powder ………………………… 43
Fig. 4-1-17 XRD data of Cu 1 powder ………………………………… 45
Fig. 4-1-18 XRD data of Cu 2 powder ………………………………… 46
Fig. 4-1-19 Oxygen contents of Cu 1 powder and deposition efficiency of coatings (a) Air annealed (1h), (b) Air annealed (6h), (c) Vacuum annealed (6h) …………………………………………………… 48
Fig. 4-1-20 Oxygen contents of Cu 2 powder and deposition efficiency of coatings (a) Air annealed (1h), (b) Air annealed (6h), (c) Vacuum annealed (6h) …………………………………………………… 49
Fig. 4-2-1 Deposition efficiency and Vickers hardness of as-coated and heat-treated Cu 1 coatings with (a) as-received powder, (b) vacuum annealed powder ………………………………… 54
Fig. 4-2-2 Deposition efficiency and Vickers hardness of as-coated and heat-treated Cu 3 coatings with (a) as-received powder, (b) vacuum annealed powder ………………………………… 55
Fig. 4-2-3 SEM image of as-coated coatings with (a) Cu 1 powder (x2000), (b) Cu 3 powder (x3000) ………………………………… 57
Fig. 4-2-4 Schematic diagram of coating mechanism (a) Cu 1 powder, (b) Cu 3 powder ………………………………………………… 59
Fig. 4-3-1 OM images of as-coated Cu coatings with vacuum annealed powder (x500) ………………………………………………… 62
Fig. 4-3-2 OM images of as-coated Cu coatings with aged (air exposed during 6 weeks after vacuum annealing) powder (x500) … 62
Fig. 4-3-3 Deposition efficiency and Vickers hardness of as-coated Cu coatings with vacuum annealed (0 week) and aged (1～6 weeks) powder ……………………………………………… 65
Fig. 4-3-4 Deposition efficiency and Vickers hardness of as-coated Cu coatings with vacuum annealed, aged, vacuum reannealed and reaged powder ……………………………………………… 66
Fig. 4-3-5 Deposition efficiency of as-coated Cu coatings with vacuum annealed, aged(air-exposed) and air unexposed powder … 67
Fig. 4-3-6 XPS data of vacuum annealed Cu powder (a) Cu 2p3/2, (b) O 1s ………………………………………………………………………… 69
Fig. 4-3-7 XPS data of aged (air exposed during 6 weeks) Cu powder (a) Cu 2p3/2, (b) O 1s …………………………………………… 70
Fig. 4-3-8 XPS data of vacuum reannealed Cu powder (a) Cu 2p3/2, (b) O 1s ……………………………………………………………… 71
Fig. 4-4-1 OM images of as-coated Cu-Sn composite coatings using Cu 1-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature (x500) ………………………………………… 75
Fig. 4-4-2 OM images of annealed Cu-Sn composite coatings using Cu 1-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature (x500) ………………………………………… 76
Fig. 4-4-3 OM images of as-coated Cu-Sn composite coatings using Cu 3-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature (x500) ………………………………………… 77
Fig. 4-4-4 OM images of as-coated Cu-Sn composite coatings using Cu 3-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature (x500) ………………………………………… 78
Fig. 4-4-5 XRD data of as-coated coatings using Cu 1-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 80
Fig. 4-4-6 XRD data of annealed coatings using Cu 1-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 81
Fig. 4-4-7 XRD data of as-coated coatings using Cu 3-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 82
Fig. 4-4-8 XRD data of annealed coatings using Cu 3-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 83
Fig. 4-4-9 EDS data of as-coated coatings using Cu 1-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 85
Fig. 4-4-10 EDS data of annealed coatings using Cu 1-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 86
Fig. 4-4-11 EDS data of as-coated coatings using Cu 3-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 87
Fig. 4-4-12 EDS data of annealed coatings using Cu 3-Sn composite under (a) 450℃, (b) 550℃, (c) 650℃ gas temperature ……… 88
Fig. 4-4-13 Coating mechanism of coatings using Cu-Sn composite by powder shape (a) Cu 1-Sn composite, (b) Cu 3-Sn composite ………………………………………………………………………… 90
Fig. 4-5-1 OM images of (a) as-coated, (b) annealed Cu matrix coatings (x500) ………………………………………………………… 93
Fig. 4-5-2 OM images of (a) as-coated, (b) annealed Sn matrix coatings (x500) ………………………………………………………… 93
Fig. 4-5-3 XRD data of (a) as-coated, (b) annealed Cu matrix coatings…95
Fig. 4-5-4 EDS data of as-coated Cu matrix coatings …………… 98
Fig. 4-5-5 EDS data of annealed Cu matrix coatings ……………… 99
Fig. 4-5-6 EDS data with line scanning of (a) as-coated, (b) annealed Cu matrix coatings ……………………………………………… 99
Fig. 4-5-7 EDS data of annealed Sn matrix coatings ………… 100
Fig. 4-5-8 Coating mechanism of Cu matrix coatings using Cu-Sn composite by feedstock ratio …………………………… 102
Fig. 4-5-9 Coating mechanism of Sn matrix coatings using Cu-Sn composite by feedstock ratio …………………………… 102
표차례(List of Table)
Table 2-3-1 Results of Vickers hardness measurements (GPa) …… 9
Table 2-3-2 Oxygen concentration in cold spray coatings and powders 9
Table 3-1-1 Chemical composition of Cu powder …………………… 15
Table 3-2-1 processing parameters of cold spray process ………… 17
Table 3-2-2 annealing parameters of powder pretreatment ……… 17
Table 3-2-3 post annealing parameters for IMC formation ………… 17
Table 4-3-1 Oxygen determinator data of vacuum annealed, aged, vacuum reannealed and reaged Cu powder ……………………… 72
