Controlling the grain size and morphology during fusion-based additive manufacturing remains a challenge for many alloys. This work investigates Titanium diboride (TiB2) nucleant particle addition to the high strength Aluminium 2319 alloy produced during wire arc additive manufacturing (WAAM). Two Cold Metal Transfer (CMT) processing conditions are explored (low heat input CMT and high heat input CMT) and the effectiveness of the grain refiner is studied. The addition of TiB2 is found to refine the average equiaxed grain size by up to 22% compared to the non-inoculated alloy. The Interdependence Model is applied to understand the grain refinement mechanisms occurring in low heat input AM technologies in alloys containing powerful growth restricting solutes such as Al 2319.
ZhangJ, SongB, Wei,Q, A review of selective laser melting of aluminium alloys: processing, microstructure, property and developing trends. J Mater Sci Technol. 2019; 35(2):270–284.
2.
RodriguesTA, DuarteV, MirandaRM, Current status and perspectives on wire and arc additive manufacturing (WAAM). Materials. 2019; 12(7):1121.
3.
DerekarKS.A review of wire arc additive manufacturing and advances in wire arc additive manufacturing of aluminium. Mater Sci Technol. 2018; 34(8):895–916.
EskinDG, KatgermanL.Mechanical properties in the semi-solid state and hot tearing of aluminium alloys. Prog Mater Sci. 2004; 49(5):629–711.
8.
FixterJ, GuJ, DingJ, Preliminary investigation into the suitability of 2xxx alloys for wire-arc additive manufacturing. Mater Sci Forum. 2016; 877:611–616.
9.
CongB, DingJ, WilliamsS.Effect of arc mode in cold metal transfer process on porosity of additively manufactured Al-6.3%Cu alloy. Int J Adv Manuf Technol. 2015; 76:1593–1606.
10.
FangX, ZhangL, HuiL, Microstructure evolution and mechanical behavior of 2219 aluminium alloys additively fabricated by the cold metal transfer process. Materials. 2018; 11(5):812.
11.
GuJ, DingJ, WilliamsSW, The strengthening effect of inter-layer cold working and post-deposition heat treatment on the additively manufactured Al-6.3Cu alloy. Mater Sci Eng A. 2016; 651:18–26.
12.
QiZ, QiB, CongB, Microstructure and mechanical properties of wire + arc additively manufactured 2024 aluminum alloy components: As-deposited and post heat-treated. J Manuf Process. 2019; 40:27–36.
13.
EastonM, StJohnD.Grain refinement of aluminium alloys: Part 1. The nucleant and solute paradigms – a review of the literature. Metall Mater Trans A. 1999; 30(6):1613–1623.
14.
SalesA, RickettsNJ.Effect of scandium on wire arc additive manufacturing of 5 series aluminium alloys. In: ChesonisC, editor. Light metals. The minerals, metals & materials series. Cham: Springer; 2019. p. 1455–1461.
15.
WangL, SuoY, LiangZ, Effect of titanium powder on microstructure and mechanical properties of wire + arc additively manufactured Al-Mg alloy. Mater Lett. 2019; 241:231–234.
16.
MoraisPJ, GomesB, SantosP, Characterization of a high-performance Al-Zn-Mg-Cu alloy designed for wire arc additive manufacturing. Materials. 2020; 13(7):1610.
17.
KleinT, SchnallM, GomesB, Wire-arc additive manufacturing of a novel high-performance Al-Zn-Mg-Cu alloy: processing, characterization and feasibility demonstration. Addit Manuf. 2021; 37:Article ID 101663. doi:10.1016/j.addma.2020.101663.
18.
Easton MSDH.A model of grain refinement incorporating alloy constitution and potency of heterogeneous nucleant particles. Acta Mater. 2001; 49(10):1867–1878.
19.
RamGJ, MitraTK, RajuMK, Use of inoculants to refine weld solidifaction structure and improve weldability in type 2090 Al-Li alloy. Mater Sci Eng A. 2000; 276(1–2):48–57.
20.
EastonM, QianM, PrasadA, Recent advances in grain refinement of light metals and alloys. Curr Opin Solid State Mater Sci. 2016; 20(1):13–24.
21.
BabuN, PanD, SunZ, Effect of titanium-boron additions on grain refinement of AA 2219 gas tungsten arc welds. Sci Technol Weld Joining. 2012; 17(5):386–393.
22.
Xi LWP, PrashanthKG, LiH, Effect of TiB2 particles on microstructure and crystallographic texture of Al-12Si fabricated by selective laser melting. J Alloys Compd. 2019; 786:551–556.
23.
Winterkorn RPA, RethmeierM.Wire arc additive manufacturing with novel Al-Mg-Si filler wire – assessment of weld quality and mechanical properties. Metals. 2021; 11(8):Article ID 1243. doi:10.3390/met11081243.
24.
BerminghamM, KentD, ZhanH, Controlling the microstructure and properties of wire arc additive manufactured Ti-6Al-4V with trace boron additions. Acta Mater. 2015; 91:289–303.
25.
TongH, UeyamaT, TanakaM, Observations of the phenomenon of abnormal arc voltage occurring in pulsed metal inert gas welding of aluminium alloy. Sci Technol Weld Joining. 2005; 10(6):695–700.
26.
XiaoP, GaoY, XuF, An investigation on grain refinement mechanism of TiB2 particulate reinforced AZ91 composites and its effect on mechanical properties. J Alloys Compd. 2019; 780:237–244.
27.
ZhangL, SongY, YangL, Synergistic effect of La and TiB(2) particles on grain refinement in aluminum alloy. Materials.2022; 15(2):600.
28.
ZhouY, LinX, KangN, Influence of travel speed on microstructure and mechanical properties of wire + arc additively manufactured 2219 aluminum alloy. J Mater Sci Technol. 2020; 37:143–153.
29.
ZhouY, LinX, KangN, Mechanical properties and precipitation behavior of the heat-treated wire + arc additively manufactured 2219 aluminium alloy. Mater Charact. 2021; 171:110735.
30.
McCartneyDG.Grain refining of aluminium and its alloys using inoculants. Int Mater Rev. 1989; 34(1):247–260.
31.
GreerA, CooperPS, MeredithMW, Grain refinement of aluminium alloys by inoculation. Adv Eng Mater. 2003; 5(12):81–91.
32.
EastonM, StJohnD.An analysis of the relationship between grain size, solute content, and the potency and number density of nucleant particles. Metall Mater Trans A. 2005; 36(7):1911–1920.
33.
YaoX, McDonaldSD, DahleAK, Modeling of grain refinement: part II. Effect of nucleant particles – TiB2 additions for aluminum. J Mater Res.2008; 23(5):1292–1300.
34.
GreerA, BunnAM, TroncheA, Modelling of inoculation of metallic melts: application to grain refinement of aluminium by Al-Ti-B. Acta Mater. 2000; 48(11):2823–2835.
35.
SpittleJA, SadliS.Effect of alloy variables on grain refinement of binary aluminium alloys with Al–Ti–B. Mater Sci Technol. 1995; 11(6):533–537.
36.
SpittleJA, BrownSGR.Computer simulation of the effects of alloy variables on the grain structures of castings. Acta Metall. 1989; 37(7):1803–1810.
37.
TanQ, ZhangJ, MoN, A novel method to 3D-print fine-grained AlSi10Mg alloy with isotropic properties via inoculation with LaB6 nanoparticles. Addit Manuf. 2020; 32:101034.
38.
MartinJH, YahataBD, HundleyJM, 3D printing of high-strength aluminium alloys. Nature. 2017; 549(7672):365–369.
39.
CongB, QiZ, QiB, A comparative study of additively manufactured thin wall and block structure with Al-6.3%Cu alloy using cold metal transfer process. Appl Sci. 2017; 7(3):275.
40.
StJohnDH, QianM, EastonMA, The interdependence theory: the relationship between grain formation and nucleant selection. Acta Mater. 2011; 59(12):4907–4921.
41.
ShuD, SunB, MiJ, A quantitative study of solute diffusion field effects on heterogeneous nucleation and the grain size of alloys. Acta Mater. 2011; 59(5):2135–2144.
42.
PatelMN, QiuD, WangG, Understanding the refinement of grains in laser surface remelted Al–Cu alloys. Scr Mater. 2020; 178:447–451.
43.
ZhangK, TianX, BerminghamM, Effects of boron addition on microstructures and mechanical properties of Ti-6Al-4V manufactured by direct laser deposition. Mater Des. 2019; 184:108191.
44.
JiaY, HuangH, FuY, An in situ investigation of the solute suppressed nucleation zone in an Al-15%wt% Cu alloy inoculated by Al-Ti-B. Scr Mater. 2019; 167:6–10.
