Effect of Heat Treatment ZA-27 Alloy On Microstructure &amp; Damping Properties

doi:10.21203/rs.3.rs-970774/v1

Download PDF

Original Article

Effect of Heat Treatment ZA-27 Alloy On Microstructure & Damping Properties

https://doi.org/10.21203/rs.3.rs-970774/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

An objective of this work, investigate effect of heat treatment on microstructure and damping behaviour of ZA-27 alloy, using dynamic mechanical analyzer. ZA-27 alloys were fabricated and solid solution treatment at 120, 240 and 360 °C for 1 hr. Microstructure and physical properties of alloy were studied by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Results observed that microstructure of ZA27 alloy manufactured as_cast was composed of α ، β ، η and ε phases, then decomposed to β phase at 360 ^oC. DMA properties as: Storage modulus, Loss modulus and Damping capacity were studied both of ZA27 alloy as-cast and heat treatment at temperature range from Room Temperature to 300 ^oC. Results indicate that specific damping capacity and loss modulus of both as-cast and heat treatment alloy alloys decreased with increases in temperature, but storage modulus decreased with temperature.

Mechanical Engineering

ZA27 alloys

microstructure

DMA

specific damping

storage modulus

Zinc-aluminum alloys are new family relatively of zinc alloys having low melting point and good casting characteristics [1]. Alloy manufacture requires energy lower than both of Aluminum and Brass and Cast Iron. That's alloys have wide range of freezing temperature, this resulting seen in different behavior of the microstructure of the alloy to each composition [2-3]. ZA27 widely used for making wear resistance parts of engine. It's used also extensively as bearing materials due to excellent castability, high damping capacity, good fluidity, low coefficient friction, its wear resistance highly in both of dry and lubrication conditions and at same time low cost production [4-8]. Thus, ZA27 has obtained more and more applications in more of industries. Finally, too interest has been attracted to investigate the dynamic mechanical analysis of ZA-27 alloy, since alloy has a good mechanical properties and high capacities of damping [9]. Different methods and techniques were used to basically improve the dynamic mechanical analysis of zinc_aluminum alloys without decreasing significantly the mechanical properties of those materials. Studies show that the dynamic mechanical analysis as damping capacities and etc. of Zn–Al alloys may be improved by solid solution heat treatment. Hardness and ductility, strengthening and dimensional shrinkage of the solutionized ZA-27 alloy through aging were studied widely, but the damping capacity variation during the process isn't more studied [10]. Materials damping capacity indicates in specially to its capability of convert mechanical vibration to thermal energy. Negative damping is too important material properties from the viewpoint of vibration adsorption in both of aerospace and submarine [11]. Metal matrix composite ''MMCs'' technology with advent, it became probable to modify damping behaviour of the metals and its alloys by combine them with a lot of phases. Cermet reinforcement metals or alloys may combine ductility, toughness of matrix composite with high strength and high modulus characteristics of the reinforcement while often retaining the same condition of damping capacity [12.13]. Material stiffness or its dynamic modulus under effect of dynamic load is useful studies of internal atomic potentials, creep behaviour and heat expansions [14]. Dynamic modulus mensuration in metal matrix composites predominantly provides more flexible and delicate alternative at standard static test technique[15-17].

Focuses of study, in determination of physical, mechanical properties of ZA27 and effect of heat treatment on storage modulus(E'), loss modulus(E") and finally damping(tan φ) both of as-cast and heat treatment as temperature function and vibration adsorbing.

The present work, selection of alloy material is important based on the survey conducted. Zinc, Aluminium, magnesium, and copper were as the alloying elements as ASTM.

Table1 Chemical Compositions of ZA-27alloy as ASTM B669-82.

Elements	Al	Cu	Mg	Zn
Percentage	25–28	1.0–2.5	0.01–0.02	Balance

Material

The Aluminum used in ZA-27 alloy was from Egyptaluminum Co., with purity 999 and Magnesium was from Alpha Chemicals, copper metal used in produce zinc aluminum alloy ZA-27 was purity 99.9 and characterized by XRD and zinc metal balance used in ZA-27 preparation was 99.99, from Boliden's Kokkola, Finland,

Experimental Details

Aluminum and copper was melting first in a common graphite crucible and balanced with zinc and finally magnesium added to molten alloy as the composition given in the Table 1. After the mixing, the crucible was placed in the furnace at a temperature range 600 ^oC. Samples cooling in air and other quenched in cold water. Quenched samples were exposed to heat treatment at 120, 240 and 360°C about 1 hr. The samples were grinded and polish for smooth surface finish using of silicon carbide papers. Nitric cid (5 % conc.) used as etching. Both of ZA27 as_cast and heat treatment samples were investigated by scanning electro Microscopy ''SEM'' with Gensis-70 with energy dispersive spectrometer (EDS). Microstructures to all samples were investigated by using X-ray diffraction (XRD), philips D_500 type, operat at 45 mA. 40 kV., characteristically XRD patterns were obtained with diffraction angle (2θ). Tensile strength of investigated samples was measured using uniaxial 350 KN capacity "Instron" machine. The dynamic mechanical analyzers ''DMA'' were instrument based on forced vibration 10 Hz. It consists of an electro-magnetic head to generation vibration waves, thermocable to measurement heat, linear variable differential transform. The specimen dimensions were 70x15x1.5 mm. Processor control unit to automatically keeping strain capacity, temperature and frequency conditions.

Densities of ZA-27 As-cast and heat treatments

The densities depend on microstructure; ZA27 alloy microstructures were acomplex assignment of casting and cooling rate and heat treatment process. Figure 1: shown the theoretical variations in experimental density. in densities differences of as cast and heat treatment samples may be due to change in dimensional of ZA-27 alloy during heat treatment, by change of meta stable phases to stable phase, which retained by non equilibrium solidification

Microstructures investigations

Microstructure of ZA-27 alloy

Microstructure ZA-27 alloy, first, α primary phase was solidified to build dendrites foundation, surround by phase β., η phase and ε phase were solidified closely in dendrite area. Microstructures, indicated dendrite multi-phase structures, like seen in Figure 2-A), a dendrite branch this is a dark contrast (Al, rich phase α), which was encompassed by thereafter solidified (Zn-rich β phase) gray color and light contrasted Zn-rich η and ε phases in the inter dendrite areas, after solid solution treatment at 120^oC for 1.hr. It can be observe the phases and shape as in as cast with out change rather, primary α-Al, despite increase of volume fraction of α phase, as shown in the low magnitude images of figure 2-B)

As ZA-27 solution treatment at 240°C lead to reduce of α-Al dendrites and η phases in to β phase as shown in figure 2c). in generally, diffusion ability of alloying elements improved at higher temperature. When ZA27 alloy heat treatment at 360°C for 1 hr., the matrix was supersaturated with β phase, where α phase appeared as a dark line, this was developed along the grain boundaries in β phase due to precipitation as shown in figure 2D)

XRD analysis of ZA-27 alloy as heat treatment

XRD patterns of ZA-27 alloy as heat treatment at 120 ^oC, 240 ^oC and 360 ^oC for 1 hr are shown in Figure 3. It was observed that the diffraction intensity of phases α, η and ε in solid solution treatment decrease in solution treatment with increase of temperature

Tensile strength and elongation investigation

The tensile strengths test results of ZA27 as_cast and heat-treatment at different temperature seen in Figure 4. It was observe in all the samples, tensile strengths decreases with increase of heat treatment temperature from 424 to 223 MPa., ZA-27 as cast >HT 120 > HT240 > HT 360 ^oC

Dynamic Mechanical Analysis of ZA-27 alloy

The storage modulus(E'), loss modulus(E") and damping(tanφ) were function of temperature, from 30°C to 300°C, for both of ZA_27 alloy ascast and ZA27 heat treatments were given in Figures 5, 6 and 7 respectively, its indicate that storage-modulus was decreases with temperature increased in ascast and treated, its decrease 12760 to 64280 Mpa as cast ZA-27, as cast >HT 120 > HT240 > HT 360 ^oC

Loss modulus was increases with temperature increases in all the cases as in figure 6, its increase from 2230 to 10765 MPa as in cast ZA-27, as cast < HT 120 < HT240 < HT 360 ^oC

Further, damping capacity was increase with increase in temperature also. its increased from 0.01760 to 0.16742 Mpa as cast ZA-27, and as cast >HT 120 > HT240 > HT 360 oC, As shown in Figure 7. Variations were more pronounced at temperatures range 250°C-300°C., this exceptional increase in damping with temperature was indicated of the low temperature volume of grain boundary relaxation, it sufficient to determine alloy plasticity

In research paper, ZA-27 alloy As_cast and heat-treatments have been perform with different physical, mechanical and thermomechanical analysis, following outputs from this study can be indicated:

1): The density of ZA-27 as cast higher than heat treatment ZA-27, may be due to change of dimensional in ZA-27 alloy during solid solution treatment and by convert of meta-stable phase to stable phase.

2): Microstructure of ZA27 as_cast content of large dendrites phase, and η phases, with increased solid solution temperature, α, η phases dissolved and convert into the β phases as seen in 360°C.

3): Tensile strength of ZA27 as cast heat treatment decrease with increase temperature.

4): Storage modulus(E') indicate to following diminishing trend: ZA27, as-cast >HT120 > HT240 > HT360, in general, storage modulus decrease with increases heat temperature

5): loss modulus(E'') increases with temperature increased of ZA27 as cast or heat treatments alloy

6): Damping capacity of ZA-27 as cast or heat treatments were also increase with temperature increase

---------------------------------------------------------------

Availability of data and materials

The materials for the experiments were purchased and the costs of the tests were paid from Self-financing

Competing Interests

The authors declare no competing financial interests.

Funding

No funding, Self-financing

Authors’ Contributions

El sayed Maree, was applied experimental and take samples to investigations, both of Amr kandil and hamdy wasly ware supervisions', and All authors read and approved the final manuscript.

Acknowledgements

Not applicable

Author Details

1: Faculty of Engineering, Mining and Metallurgy & Petroleum Department, Al-Azhar University, P.O. Box: 5043, Qena, Egypt

2: Faculty of Engineering, Mining and Metallurgy & Petroleum Department, Al-Azhar University, P.O.Box 11884, Cairo, Egypt

3: Faculty of Engineering, Mining and Metallurgy & Petroleum Department, Al-Azhar University, P.O. Box: 5043, Qena, Egypt

Corresponding author: [email protected], ORCID ID: 0000-0002-6716-7716, phone: +20 1129487720

Shanta Sastry, M. Krishna, and Jayagopal Uchil, Effect of Thermal Stresses on the Thermal Expansion and Damping Behavior of ZA-27/Aluminite Metal Matrix Composites, Journal of Materials Engineering and Performance, Volume 10, 2001
E. Gervais, R.J. Barnhurst, and C.A. Loong: J. Met., 1985, vol. 37, pp. 43–47,
H. Le Huy and G.L. Esperance: Jour Mater. Sci., 1991, vol. 26, pp. 559–68.
Mao F, Chen F, Yan G, et al. Effect of strontium addition on silicon phases and mechanical properties of Zn–27Al–3Si alloy. J Alloys Compd 2015; 622: 871–879.
Zhao C, Yu X, Huang Q, et al. Analysis on the load characteristics and coefficient of friction of angular contact ball bearing at high speed. Tribol Int 2015; 87:50–56.
Fernandez LE, Borrell A, Salvador MD, et al. Sliding wear behavior of WC-Co-Cr3C2-VC composite fabricated by conventional and non-conventional techniques. Wear 2013; 307: 60–67.
Ejiofo JU, Okorie BA and Reddy RG. Powder pressing and properties of zircon reinforced Al-13.5Si-2.5Mg alloy composites. J Mater Eng Perform 1997
A.H. Sajeeb Rahiman, D.S. Robinson Smart, Damping Characteristics of Aluminium Matrix Composites – A Review
Seah KHW, Sharma SC, Girish BM. Mechanical properties of as-cast and heattreated ZA-27/graphite particulate composites. Mater Des 1997
Wang J, Zhang Z, Yang G. The dependence of damping capacity of PMMCs on strain amplitude. Compos Mater Sci 2000;18:205–11
Joseph E. Bishop and Vikram K.Kinra, "Analysis of elastothermodynamic damping in particle reinforced metal-matrix composites", Metall. Trans., 26A, 2773-2782 (1995).
G.J.C. Carpenter and S.H.J. Lo; "Characterization of graphite-aluminium composites using analytical electron microscopy", J. Mater. Sei., 27, 1827–1841 (1992).
I. A. Ibrahim, F. A. Mohamed and E.J. Lavernia, "Particulate reinforced metal matrix composites – A review" J Mater. Sei., (1991). 137
Α. Wolfenden and J.M.Wolla, in: Metal Matrix Composites Mechanisms and Properties, R.K. Everett and R.J. Arsenault, (eds.), Academic Press, Boston, MA., 1991; pp. 287–328.
G. Ranganath, S.C. Sharma and M. Krishna, Effect of garnet particle on. the mechanical and microstrural properties of ZA-27 alloy composites, J. mechanical Behaviour of Materials, 12 (4), 240–254 (2001).
Liu Yongzhang, Yang Liushuan, Yang Gencang, Lü Yili, Damping Capacities and Discussion of Micro-mechanical Model of High Silicon ZA27 Alloy, Powder Metallurgy Technology, 1996, 14(3): 163-167,

Download PDF

Version 1

posted

You are reading this latest preprint version

Effect of Heat Treatment ZA-27 Alloy On Microstructure & Damping Properties

Status:

Version 1

Abstract

Figures

Introduction

Methods And Materials

Material

Experimental Details

Results And Discussion

Microstructures investigations

Tensile strength and elongation investigation

Dynamic Mechanical Analysis of ZA-27 alloy

Conclusions

Declarations

References

Status:

Version 1