1 AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China 2 Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation, Beijing 100095, China 3 Key Laboratory of Aeronautical Materials Testing and Evaluation, Aero Engine Corporation of China, Beijing 100095, China
GH3536 superalloy samples were made by selective laser melting (SLM) with a parameter combination of laser power and scanning speed. The porosity and defect characteristics within the samples were characterized by μCT technique, and the defect types as well as the morphologies of molten pool were analyzed using optical microscope and scanning electron microscope. The results show that process parameters are closely related with defect characteristics and the morphologies of molten pool. As the laser power and scanning speed are optimized, continuous molten pool with a higher aspect ratio overlaps well with each other. The porosity in the fabricated samples is far less than 0.01%, and with randomly distributed small pores. When the deviation from the optimized process parameters occurs, not only larger voids are formed at the interface of discontinuous molten pool, but also the process instability are increased, resulting in the formation of minor amounts of lamellar lack of fusion. The latter two types of defects present a certain anisotropy. Additionally, smaller micropores and microcracks are beyond the μCT detection ability.
LIU H , WANG X M , LIU D S , et al. Influence of notch on creep properties of GH3536 nickel-based superalloy[J]. Rare Metal Materials and Engineering, 2014, 43 (10): 2473- 2478.
2
KRUTH J P , MERCELIS P , VAERENBERGH J V , et al. Binding mechanisms in selective laser sintering and selective laser melting[J]. Rapid Prototyping Journal, 2005, 11 (1): 26- 36.
doi: 10.1108/13552540510573365
3
CHI C N , SAVALANI M , MAN H C . Fabrication of magnesium using selective laser melting technique[J]. Rapid Prototyping Journal, 2011, 17 (6): 479- 490.
doi: 10.1108/13552541111184206
4
SUN J F , YANG Y Q , WANG D . Mechanical properties of Ti6Al4V octahedral porous material unit formed by selective laser melting[J]. Advances in Mechanical Engineering, 2012, 4 (9): 742- 760.
ZHANG X J , TANG S Y , ZHAO H Y , et al. Research status and key technologies of 3D printing[J]. Journal of Materials Engineering, 2016, 44 (2): 122- 128.
6
VRANCKEN B , THIJS L , KRUTH J , et al. Heat treatment of Ti6Al4V produced by selective laser melting: microstructure and mechanical properties[J]. Journal of Alloys and Compounds, 2012, 541, 177- 185.
doi: 10.1016/j.jallcom.2012.07.022
7
RAFI H K , STARR T L , STUCKER B E . A comparison of the tensile, fatigue and fracture behavior of Ti-6Al-4V and 15-5 PH stainless steel parts made by selective laser melting[J]. The International Journal of Advanced Manufacturing Technology, 2013, 69 (5): 1299- 1309.
8
BRANDL E , HECKENBERGER U , HOLZINGER V , et al. Additive manufactured AlSi10Mg samples using selective laser melting (SLM): microstructure, high cycle fatigue and fracture behavior[J]. Materials & Design, 2012, 34 (1): 159- 169.
doi: 10.3969/j.issn.1006-2890.2012.01.102
9
BEAN G E , MCLOUTH T D , WITKIN D B , et al. Build orientation effects on texture and mechanical properties of selective laser melting inconel 718[J]. Journal of Materials Engineering and Performance, 2019, 28 (4): 1942- 1949.
doi: 10.1007/s11665-019-03980-w
ZHAO Z G , BAI L , LI L , et al. Status and process of selective laser melting forming technology[J]. Aviation Manufacturing Technology, 2014, (19): 46- 49.
doi: 10.3969/j.issn.1671-833X.2014.19.005
GONG S L , LI H X , SUO H B , et al. Application and development of high energy beam manufacturing technology[J]. Aviation Manufacturing Technology, 2009, (14): 34- 39.
doi: 10.3969/j.issn.1671-833X.2009.14.003
12
LEUDERS S , THONE M , RIEMER A , et al. On the mechanical behavior of titanium alloy TiAl6V4 manufactured by selective laser melting: fatigue resistance and crack growth performance[J]. International Journal of Fatigue, 2013, 48, 300- 307.
doi: 10.1016/j.ijfatigue.2012.11.011
13
MEZZETTA J , CHOI J P , MILLIGAN J , et al. Microstructure-properties relationships of Ti-6Al-4V parts fabricated by selective laser melting[J]. International Journal of Precision Engineering and Manufacturing-Green Technology, 2018, 5 (5): 605- 612.
doi: 10.1007/s40684-018-0062-1
14
CAIN V , THIJS L , HUMBEECK J V , et al. Crack propagation and fracture toughness of Ti6Al4V alloy produced by selective laser melting[J]. Additive Manufacturing, 2015, 5, 68- 76.
doi: 10.1016/j.addma.2014.12.006
15
VILARO T , COLIN C , BARTOUT J D . As-fabricated and heat-treated microstructures of the Ti-6Al-4V alloy processed by selective laser melting[J]. Metallurgical Materials Transactions A, 2011, 42 (10): 3190- 3199.
doi: 10.1007/s11661-011-0731-y
16
ZHANG L , SONG J , WU W H , et al. Effect of processing parameters on thermal behavior and related density in GH3536 alloy manufactured by selective laser melting[J]. Journal of Materials Research, 2019, 34 (8): 1- 10.
SUN S S , TENG Q , CHENG T , et al. Influence of heat treatment on microstructure evolution of GH3536 superalloy fabricated by selective laser melting[J]. Journal of Mechanical Engineering, 2020, 56 (21): 208- 218.
SHI L , LEI L M , WANG W , et al. Effects of hot isostatic pressing and heat treatment process on microstructure and tensile properties of selective laser melting manufactured GH4169 alloy[J]. Journal of Materials Engineering, 2020, 48 (6): 148- 155.
ZONG X W , LIU W J , ZHANG S Z , et al. Microstructure and crystal orientation of nickel-based superalloy GH3536 by selective laser melting[J]. Rare Metal Materials and Engineering, 2020, 49 (9): 3182- 3188.
20
THOMPSON A , MASKERY I , LEACH R K . X-ray computed tomography for additive manufacturing: a review[J]. Measurement Science and Technology, 2016, 27, 1- 16.
21
ZIOLKOWSKI G , CHLEBUS E , SZYMCZYK P , et al. Application of X-ray CT method for discontinuity and porosity detection in 316L stainless steel parts produced with SLM technology[J]. Archives of Civil and Mechanical Engineering, 2014, 14, 608- 614.
doi: 10.1016/j.acme.2014.02.003
22
SIMCHI A , PETZOLDT F , POHL H . On the development of direct metal laser sintering for rapid tooling[J]. Journal of Materials Processing Technology, 2003, 141 (3): 319- 328.
doi: 10.1016/S0924-0136(03)00283-8
23
WANG D , WU S B , FU F , et al. Mechanisms and characteristics of spatter generation in SLM processing and its effect on the properties[J]. Materials & Design, 2017, 117, 121- 130.
24
YADROITSEV I , GUSAROV A , YADROITSAVA I , et al. Single track formation in selective laser melting of metal powders[J]. Journal of Materials Processing Technology, 2010, 210 (12): 1624- 1631.
doi: 10.1016/j.jmatprotec.2010.05.010
25
OSAKADA K , SHIOMI M . Flexible manufacturing of metallic products by selective laser melting of powder[J]. International Journal of Machine Tools and Manufacture, 2006, 46 (11): 1188- 1193.
doi: 10.1016/j.ijmachtools.2006.01.024
ZHANG G H , GUO S Q , HUANG S , et al. Relative density of GH4169 superalloy prepared by selective laser melting[J]. Laser & Optoelectronics Progress, 2020, 57 (3): 1- 7.
27
MASKERY I , ABOULKHAIR N T , CORFIEL M R , et al. Quantification and characterization of porosity in selectively laser melted Al-Si10-Mg using X-ray computed tomography[J]. Materials Characterization, 2016, 111, 193- 204.
doi: 10.1016/j.matchar.2015.12.001
28
TAMMAS-WILLIAMS S , ZHAO H , LEONARD F , et al. XCT analysis of the influence of melt strategies on defect population in Ti-6Al-4V components manufactured by selective electron beam melting[J]. Materials Characterization, 2015, 102, 47- 61.
doi: 10.1016/j.matchar.2015.02.008
LIU K , WANG R , QI H , et al. Microstructure and tensile properties of GH3536 alloy formed by SLM[J]. Physical Testing and Chemical Analysis: Part A, 2019, 55 (1): 15- 18.
2022, Vol. 50 
), 杨平华1,2,3, 乔海燕1,2,3, 张帅1
