We give thanks to the financial support of the National Natural Science Foundation of China (11076109), the Hong Kong Scholars Program (XJ2014045, G-YZ67), the "1000 Talents Plan" of the Sichuan Province, the Talent Introduction Program of Sichuan University (YJ201410), and the Innovation and Creative Experiment Program of Sichuan University (20171060, 20170133).

1. Preparation of the Raw Materials
<ol>
	<li>Weigh all the required raw materials with an electronic scale by mass percentage (65% electrolytic Mn, 26% electrolytic Cu, 2% industrial pure Fe, 2% electrolytic Ni, 3% electrolytic Al, and 2% electrolytic Zn), as shown in Figure 1. 
	&#8203;NOTE: All these raw materials were commercially available.</li>
</ol>
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57180/57180fig...

<ol>
	<li>Zener, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Elasticity and anelasticity of metals. , (1948).</li><li>Jensen, J. W., Walsh, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manganese-Copper+damping+alloys.">Manganese-Copper damping alloys.</a> Bulletin 624. , (1965).</li><li>Wang, X. Y., Peng, W. Y., Zhang, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Martensitic+twins+and+antiferromagnetic+domains+in+gamma-MnFe(Cu)+alloy.">Martensitic twins and antiferromagnetic domains in gamma-MnFe(Cu) alloy.</a> Materials Science and Engineering A. 438, 194-197 (2006).</li><li>Wang, X. Y., Zhang, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+of+twin+boundaries+in+Mn-based+shape+memory+alloy:+a+HRTEM+study+and+the+strain+energy+driving+force.">Structure of twin boundaries in Mn-based shape memory alloy: a HRTEM study and the strain energy driving force.</a> Acta Materialia. 55 (15), 5169-5176 (2007).</li><li>Yin, F. X., Ohsawa, Y., Sato, A., Kawahara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decomposition+behavior+of+the+gamma(Mn)+solid+solution+in+a+Mn-20Cu-8Ni-2Fe+(at%)+alloy+studied+by+a+magnetic+measurement.">Decomposition behavior of the gamma(Mn) solid solution in a Mn-20Cu-8Ni-2Fe (at%) alloy studied by a magnetic measurement.</a> Materials Transactions,JIM. 40 (5), 451-454 (1999).</li><li>Dean, R. S., Potter, E. V., Long, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+of+transitional+structures+in+Copper-Manganese+alloys.">Properties of transitional structures in Copper-Manganese alloys.</a> Metallurgical and Materials Transactions, ASM. 34, 465-500 (1945).</li><li>Yin, F. X., Ohsawa, Y., Sato, A., Kawahara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+dependent+damping+behavior+in+a+Mn-18Cu-6Ni-2Fe+alloy+continuously+cooled+in+different+rates+from+the+solid+solution+temperature.">Temperature dependent damping behavior in a Mn-18Cu-6Ni-2Fe alloy continuously cooled in different rates from the solid solution temperature.</a> Scripta Materialia. 38 (9), 1314-1346 (1998).</li><li>Findik, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvements+in+spinodal+alloys+from+past+to+present.">Improvements in spinodal alloys from past to present.</a> Materials and Design. 42 (42), 131-146 (2012).</li><li>Yan, J. Z., Li, N., Fu, X., Zhang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+strengthening+effect+of+spinodal+decomposition+and+twinning+structure+in+MnCu-based+alloy.">The strengthening effect of spinodal decomposition and twinning structure in MnCu-based alloy.</a> Materials Science and Engineering A. 618, 205-209 (2014).</li><li>Soriano-Vargas, O., Avila-Davila, E. O., Lopez-Hirata, V. M., Cayetano-Castro, N., Gonzalez-Velazquez, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+spinodal+decomposition+on+the+mechanical+behavior+of+Fe-Cr+alloys.">Effect of spinodal decomposition on the mechanical behavior of Fe-Cr alloys.</a> Materials Science and Engineering A. 527 (12), 2910-2914 (2010).</li><li>Yin, F. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Damping+behavior+characterization+of+the+M2052+alloy+aimed+for+practical+application.">Damping behavior characterization of the M2052 alloy aimed for practical application.</a> Acta Metallurgica Sinica. 39 (11), 1139-1144 (2003).</li><li>Yin, F. X., Ohsawa, Y., Sato, A., Kohji, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decomposition+of+high+temperature+gamma(Mn)+phase+during+continuous+cooling+and+resultant+damping+behavior+in+Mn74.8Cu19.2Ni4.0Fe2.0+and+Mn72.4Cu20.0Ni5.6Fe2.0+alloys.">Decomposition of high temperature gamma(Mn) phase during continuous cooling and resultant damping behavior in Mn74.8Cu19.2Ni4.0Fe2.0 and Mn72.4Cu20.0Ni5.6Fe2.0 alloys.</a> Materials Transactions, JIM. 39 (8), 841-848 (1998).</li><li>Sakaguchi, T., Yin, F. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Holding+temperature+dependent+variation+of+damping+capacity+in+a+MnCuNiFe+damping+alloy.">Holding temperature dependent variation of damping capacity in a MnCuNiFe damping alloy.</a> Scripta Materialia. 54 (2), 241-246 (2006).</li><li>Tanji, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+damping+performance+of+M2052+alloy+at+cryogenic+temperatures.">Measurement of damping performance of M2052 alloy at cryogenic temperatures.</a> Journal of Alloys and Compounds. 355 (1-2), 207-210 (2003).</li><li>Yin, F. X., Iwasaki, S., Sakaguchi, T., Nagai, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Susceptibility+of+damping+behavior+to+the+solidification+condition+in+the+as-cast+M2052+high-damping+alloy.">Susceptibility of damping behavior to the solidification condition in the as-cast M2052 high-damping alloy.</a> Key Engineering Materials. 319, 67-72 (2006).</li><li>Yin, F. X., Ohsawa, Y., Sato, A., Kawahara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+strain-amplitude+and+frequency+dependent+damping+capacity+in+the+M2052+alloy.">Characterization of the strain-amplitude and frequency dependent damping capacity in the M2052 alloy.</a> Materials Transactions, JIM. 42 (3), 385-388 (2001).</li><li>Zhong, Z. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mn+segregation+dependence+of+damping+capacity+of+as-cast+M2052+alloy.">Mn segregation dependence of damping capacity of as-cast M2052 alloy.</a> Materials Science and Engineering A. 660, 97-101 (2016).</li><li>Liu, W. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+cast-aged+MnCuNiFeZnAl+alloy+with+good+damping+capacity+and+high+service+temperature+toward+engineering+application.">Novel cast-aged MnCuNiFeZnAl alloy with good damping capacity and high service temperature toward engineering application.</a> Materials Design. 106, 45-50 (2016).</li><li>Cowlam, N., Shamah, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+diffraction+study+of+y-Mn-Cu+alloys.">A diffraction study of y-Mn-Cu alloys.</a> Journal of Physics F: Metal Physics. 11 (1), 27-43 (1981).</li><li>Yan, J. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+pre-deformation+and+subsequent+aging+on+the+damping+capacity+of+Mn-20+at.%Cu-5+at.%Ni-2+at.%Fe+alloy.">Effect of pre-deformation and subsequent aging on the damping capacity of Mn-20 at.%Cu-5 at.%Ni-2 at.%Fe alloy.</a> Advanced Engineering Materials. 17 (9), 1332-1337 (2015).</li><li>Zhang, Y., Li, N., Yan, J. Z., Xie, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+the+precipitated+second+phase+during+aging+on+the+damping+capacity+degradation+behavior+of+M2052+alloy.">Effect of the precipitated second phase during aging on the damping capacity degradation behavior of M2052 alloy.</a> Advances in Materials Research. 873, 36-41 (2014).</li><li>Yin, F. X., Ohsawa, Y., Sato, A., Kawahara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-ray+diffraction+characterization+of+the+decomposition+behavior+of+gamma(Mn)+phase+in+a+Mn-30+at.%+Cu+alloy.">X-ray diffraction characterization of the decomposition behavior of gamma(Mn) phase in a Mn-30 at.% Cu alloy.</a> Scripta Materialia. 40 (9), 993-998 (1999).</li><li>Yin, F. X., Ohsawa, Y., Sato, A., Kawahara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase+decomposition+of+the+gamma+phase+in+a+Mn-30+at.%+Cu+alloy+during+aging.">Phase decomposition of the gamma phase in a Mn-30 at.% Cu alloy during aging.</a> Acta Materialia. 48 (6), 1273-1282 (2000).</li><li>Ritchie, I. G., Sprungmann, K. W., Sahoo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Internal-friction+in+Sonoston+-+a+high+damping+Mn/Cu-based+alloy+for+marine+propeller+applications.">Internal-friction in Sonoston - a high damping Mn/Cu-based alloy for marine propeller applications.</a> Journal De Physique. 46 (C-10), 409-412 (1985).</li><li>Kawahara, K., Sakuma, N., Nishizaki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Fourth+Elements+on+Damping+Capacity+of+Mn-20Cu-5Ni+Alloy.">Effect of Fourth Elements on Damping Capacity of Mn-20Cu-5Ni Alloy.</a> Journal of the Japan Institute of Metals. 57 (9), 1097-1100 (1993).</li></ol>

To ensure that this kind of as-cast Mn-Cu-based alloy possesses both&#160;superior damping capacity and excellent mechanical properties, it is necessary to ensure that the castings have a stable chemical composition, a high purity, and an excellent crystal structure. Therefore, strict quality control is necessary for the smelting, pouring, and heat treatment processes.
Firstly, it is necessary to choose the proper ingredients for the alloy. It should be considered that the added alloy elements...

Since the Mn-Cu alloys were found by Zener to have&#160;damping capacity1, they have received widespread attention and research2. The advantages of Mn-Cu alloy are that it has&#160;high damping capacity, especially at low strain amplitudes, and its damping capacity cannot be disturbed by a magnetic field, which is quite different from ferromagnetic damping alloys. The high damping capacity of Mn-Cu-based alloys can be mainly attributed to the movability of the internal boundaries, mainly including twin boundaries and phase boundaries, which are generated in the face-centered-cubic-to-face-centered-tetragonal (f.c.c.-f.c.t.) phase transition under the martensite transformation temperature (Tt)3. It has been found that Tt depends directly on the Mn content in the Mn-Cu-based alloy4,5; that is, the higher the Mn content, the higher the Tt and the better the damping capacity of the material. The alloy, which contains more than 80 at% manganese, was found to have&#160;high damping capacity and optimum strength when quenched from the solid-solution temperature6. However, the higher Mn concentration in the alloy would directly cause the alloy to be more brittle and have a lower elongation, impact toughness, and a worse corrosion resistance, which means the alloy will not meet the engineering requirements. Previous research findings revealed that an aging treatment under suitable conditions is an effective way to reconcile this problem; for instance, Mn-Cu-based damping alloys containing 50 - 80 at% Mn can also obtain a high Tt and&#160;favorable damping capacity by an aging treatment in the appropriate temperature range7. This is due to the decomposition of the &#947;-parent phase into nanoscale Mn-rich regions and nanoscale Cu-rich regions while aging in the temperature range of the miscibility gap8,9,10, which is considered to improve Tt of this alloy along with its damping capacity. Clearly, it is an effectual method which can combine&#160;high damping capacity with excellent workability.
M2052 alloy used for forging forming, a representative Mn-Cu-based high-damping alloy with medium Mn content developed by Kawahara et al.11, has been extensively studied in the last few decades. Researchers found that M2052 alloy has a good sweet spot between damping capacity, yield strength, and workability. Compared with the forging technique, casting has been widely used so far due to the simple molding process, low production costs, and high productivity, etc. The influential factors (e.g., oscillation frequency, strain amplitude, cooling velocity, heat treatment temperature/time, etc.) on the damping capacity, microstructure, and damping mechanism of M2052 alloy have been studied by some researchers12,13,14,15,16,17,18. Nevertheless, the casting performance of M2052 alloy is inferior, for instance, a wide range of crystallization temperature, the occurrence of casting porosity, and concentrated shrinkage, eventually resulting in the unsatisfactory mechanical properties of the castings.
The purpose of this paper is to provide the industrial field with a feasible method of obtaining a cast Mn-Cu based alloy with excellent properties which can be used in machinery and in the precision instruments industry to reduce vibration and ensure the product quality. According to the effect of alloying elements on the phase transformation and the casting performance, Al element is considered to reduce the &#947;-phase region and the stability of the &#947; phase, which can make the &#947; phase more easily transform into a &#947;&#39; phase with micro-twins. Moreover, the solution of Al atoms in the &#947; phase will increase the strength of the alloy, which can improve the mechanical properties. Also, Al element is one of the important elements which can improve the casting properties of Mn-Cu alloy. Zn element is beneficial to improving the casting and damping properties of the alloy. Finally, 2 wt% Zn and 3 wt% Al were added to the MnCuNiFe quaternary alloy in this work and a new cast Mn-26Cu-12Ni-2Fe-2Zn-3Al (wt%) alloy was developed. Furthermore, several different heat treatment methods are used in this work and their distinct effects are discussed as follows. The homogenization treatment was used to reduce dendrite segregation. The solution treatment was used for impurities immobilization. The aging treatment is used for triggering spinodal decomposition; meanwhile, the various aging times are used for seeking out the optimizing parameters for both excellent damping capacity and a high service temperature. Ultimately, a preferable heat treatment method was screened for superior damping capacity, as well as a high service temperature.
It turns out that the maximum internal friction (Q-1) and the highest service temperature can be achieved concurrently by aging the alloy at 435 &#176;C for 2 h. Because of the simplicity and efficiency of this preparation method, a novel as-cast Mn-Cu-based damping alloy with excellent performance can be produced, which is of important practical significance for its engineering application. This method is particularly suitable for the preparation of casting Mn-Cu-based high damping alloy which can be used for vibration reduction.

<table border="0" cellpadding="0" cellspacing="0" style="width:747px;" width="747">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:163px;">manganese</td>
			<td style="width:299px;">Daye Nonferrous Metals Group Holdings Co., Ltd.</td>
			<td style="width:119px;">DJMnB</td>
			<td style="width:167px;">produced by electrolysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:163px;">copper</td>
			<td>Daye Nonferrous Metals Group Holdings Co., Ltd.</td>
			<td style="width:119px;">Cu-CATH-2</td>
			<td>produced by electrolysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:163px;">Nickel</td>
			<td>Daye Nonferrous Metals Group Holdings Co., Ltd.</td>
			<td>Ni99.99</td>
			<td>produced by electrolysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Iron</td>
			<td style="width:299px;">Ningbo Jiasheng Metal Materials Co., Ltd.</td>
			<td>YT01</td>
			<td>industrial pure Fe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Zinc</td>
			<td>Daye Nonferrous Metals Group Holdings Co., Ltd.</td>
			<td>0#</td>
			<td>produced by electrolysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Aluminum</td>
			<td>Daye Nonferrous Metals Group Holdings Co., Ltd.</td>
			<td>Al99.90</td>
			<td>produced by electrolysis</td>
		</tr>
	</tbody>
</table>

an available technique for preparation of new cast mncunifeznal alloy with superior damping capacity and high service temperature

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. M2052 (Mn-20Cu-5Ni-2Fe, at%) is an important branch of Mn-Cu-based alloys, which possesses both excellent damping capacity and processability. In recent decades, lots of studies have been carried out on the performance optimization of M2052, improving the damping capacity, mechanical properties, corrosion resistance, and service temperature, etc. The major methods of performance optimization are alloying, heat treatment, pretreatment, and different ways of molding etc., among which alloying, as well as adopting a reasonable heat treatment, is the simplest and most effective method to obtain perfect and comprehensive performance. To obtain the M2052 alloy with excellent performance for casting molding, we propose to add Zn and Al to the MnCuNiFe alloy matrix and use a variety of heat treatment methods for a comparison in the microstructure, damping capacity, and service temperature. Thus, a new type of cast-aged Mn-22.68Cu-1.89Ni-1.99Fe-1.70Zn-6.16Al (at.%) alloy with&#160;superior damping capacity and high service temperature is obtained by an optimized heat treatment method. Compared with the forging technique, cast molding is simpler and more efficient, and the damping capacity of this as-cast alloy is excellent. Therefore, there is a suitable reason to think that it is a good choice for engineering applications.

Figure 7&#160;shows the dependency of the damping capacity on the strain amplitude for the as-cast MnCuNiFeZnAl alloy specimens #1 - #7 and as-cast M2052. The results show that the damping capacity of specimen #1 is higher than that of cast M2052 alloy (as shown in Figure 7a) and the traditional forged M2052 high-damping alloy mentioned in previous articles20,21. Moreover...

Watch this Scientific Journal Video about An Available Technique for Preparation of New Cast MnCuNiFeZnAl Alloy with Superior Damping Capacity and High Service Temperature at JoVE.com

An Available Technique for Preparation of New Cast MnCuNiFeZnAl Alloy with Superior Damping Capacity and High Service Temperature

Here we present a protocol to obtain a novel Mn-Cu-based alloy with excellent comprehensive performances by a high-quality smelting technology and reasonable heat treatment methods.

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. ...

The purpose of this work is to design and develop a noble cast age manganese-copper-nickel-iron-zinc-aluminum alloy with superior damping capacity and high usage temperature, which can act as a promising candidate towards engineering applications. The brief preparation process is as follows. The first step is to prepare raw materials.The second is to melt these pure metals in a vacuum induction melting furnace and desert atmosphere. The third is to get the alloy castings by custom molten alloy liquid into silica sand mold smoothly. The fourth is to remove the castings by breaking up the sand mold when the temperature of the mold drops to a low level.The fifth is to make the specimens from alloy castings subject to different heat treatments. Finally, thin microstructure, damping capacity, and usage temperature are investigated systematically by a series of characterization and test methods. Manganese-copper based alloys have been found to have damping capacity to reduce noise and vibration, which can be mainly attributed to the lattice distortion induced twin boundaries produced by face centered cubic, two faced centered tetragonal face transformation below the face transformation point.While the face transformation temperature is directly dependent on the manganese content in manganese copper based alloys. That is to say, the higher the manganese concentration, the greater the lattice distortion is. The higher the Martensitic transformation temperature is, the more the FCT phase microtests damping saws obtained at room temperature is.Thus, the better the damping capacity is. Among these manganese-copper based alloys, forged manganese-copper-nickel-iron alloy have been widely studied and used in the past decades. The researchers found that this kind of alloy can reach good damping capacity by aging treatment in appropriate temperature range, which is mainly due to the decomposition of gamma parent phase into nanoscale manganese rich ridges and nanoscale copper rich ridges, resulting in the improvement of damping capacity.Compared with forge and forming, casting has been widely used so far, due to the simple manufacturing process, low integrated cost, and high production efficiency, etc. The research group and other lead researchers have investigated the influence factors on damping capacity and microstructure of S cast of M2052 alloy. However, the M2052 alloy was defective in castability.For example, a wide range of crystallization temperature, the up risk of casting porosity, concentrated shrinkage, and so on, eventually leading to the unsatisfactory mechanical practice. Therefore, in order to resolve these problems, zinc and aluminum elements are added in the manganese-copper-nickel-iron alloy metrics in this work to improve its casting performance, and the preferable heat treatment process is screened for both good damping capacity and high usage temperature. Finally, a new type of manganese-copper-nickel-iron-zinc-aluminum casting aged alloy, with excellent damping capacity and high usage temperature, were obtained by alloy design and heat treatment optimization.Therefore, there's a suitable reason to think that it is a good choice for engineering applications. Prepare raw materials. Prepare the new alloy by 65%electrolytic manganese, 26%electrolytic copper, 2%industrial pure iron, 2%electrolytic deco, 3%electrolytic aluminum, and 2%electrolytic zinc.The raw materials were commercially available. Melting and casting process. Use a medium frequency vacuum induction melting furnace in the experiment.Firstly, prepare patterns. Use two wood patterns in this work. Make sure that the size of the pattern is slightly enlarged to account for shrinkage, and machining allows this.Secondly, prepare molding sand. Mix 4%to 8%sodium silicate and quartz sand together. Then, make the mold by hand.Put two patterns in the molding flask. Then, roll over the flask after ramming the molding sand around the patterns and withdraw the patterns from sand. Brush the surface of the sand mold with coating for sand casting to improve casting surface quality and reduce casting defects.At last, to obtain a dry sand mold, put the sand mold in an oven to bake it at 180 degrees for more than eight hours. Thirdly, fit in raw materials. Open the furnace lid, put manganese, copper nickel, iron, zinc, and aluminum materials in the crucible.Cover the materials with dry light at last. Fourthly, take out the casting mold from the oven and put it in the furnace. Adjust its position for successful pouring.Close the lid, vacuum the furnace, and open the heat distribution system to start melting alloy. Pour the molten metal smoothly into the casting mold after the refining process. Finally, after molten metal is completely solidified, take out the casting mold.Remove the castings from the casting mold when the temperature of the mold drops to a low level. Pretreatment of castings. Cut specimens from the casting using linear cutting machine.The specimens for XRD measurements and metallographic observation are in size of ten times ten times one millimeter. The specimens for DNA measurement possess a dimension of 0.8 times ten times thirty-five millimeter. Heat treatment.Divide the polishing specimens into seven groups, among which specimens one were free of treatment. Maintaining a cast state for commemoration and put others in a box type resistance oven for different heat treatments. The purpose of homogenization treatment is to reduce dendritic segregation.The purpose of solution treatment is to immobilize impurities, as well as different aging times are used to find out the optimal parameters for excellent damping capacity and usage temperature. Test damping capacity. Use dynamic mechanical analysis for damping capacity measurement of specimens.During the test, detect the face angle data between the stress applied to the specimen and the strain produced on the specimen. Then, characterize the damping capacity by q to the power of minus one. Which is determined by the formula q to the power of minus one equal to tangent delta.The larger the delta value, the better the damping capacity. Simple characterization. For dendrites microstructure observation, etch all specimens for about one minute in a mixed solution of perchloric acid and alcohol after mechanical polishing.Then, clean the specimens with acetone. Dry the sample with a blower and observe the dendritic structure with a metallographic microscope. Figure seven shows the strength amplitude dependency of q to the power of minus one for its cast manganese-copper-nickel-iron-zinc-aluminum alloy specimens, number one to number seven, and its cast M2052.These curves show that subsequently carrying out homogenization aging, solution aging, and aging further improved the damping capacity of the S cast manganese-copper-nickel-iron-zinc-aluminum alloy respectively. In which, aging for two hours, result in the highest damping capacity among them. Figure eight shows the effect of heat treatment on microscopic manganese dendrite segregation.Compared with the microstructure of specimen one, the manganese dendrite segregations of specimen five and six are weakened to some extent, while the counterpart of specimen seven has no distinctive difference. These results indicate that the homogenization aging and solution aging treatments weaken the microscopic manganese segregation, but the direct aging treatment has no obvious effect on it. According to the temperature dependent damping capacity curve, the damping capacity decreases rapidly and the temperature rises.The surface temperature of specimen one, five through seven, are listed in Table 2. It can be seen clearly that aging at 435 degrees for two hours can call the optimal usage temperature. Figure nine shows the relationship among lattice distortion, q to the power of minus one, and usage temperature of S cast manganese-copper-nickel-iron-zinc-aluminum alloys subject to different heat treatments.Evidently, the lattice distortion is positively related to the q to the power of minus one and usage temperature. Namely, the larger the lattice distortion, the better the damping capacity and usage temperature. All the results indicate that the optimal damping capacity of the highest usage temperature are achieved by aging at 435 degrees for two hours of S cast manganese-copper-nickel-iron-zinc-aluminum alloy, mainly due to the greatest nanoscale manganese segregation, resulting in the maximum lattice distortion in the alloy.And noble S cast manganese-copper-nickel-iron-zinc-aluminum alloy, with superior damping capacity and high usage temperature, has been obtained by alloy design and heat treatment optimization in this work. The optimum heat treatment process is aging at 435 degrees for two hours, which can lead to the greatest nanoscale manganese segregation, thus significantly improving damping capacity and usage temperature compared with the original S cast alloy. This work will be of great significance in the design and preparation of new manganese-copper based damping alloys with excellent properties for practical industrial applications.

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Research

JoVE Journal

Engineering

6.8K visualizações.  Sichuan University. O objetivo deste trabalho é projetar e desenvolver uma nobre liga de manganese-cobre-níquel-ferro-zinco-alumínio com maior capacidade de amortecimento e alta temperatura de uso, que pode atuar como um candidato promissor para aplicações de engenharia. O breve processo de preparação é o seguinte. O primeiro passo é preparar matérias-primas.A segunda é derreter esses metais puros em um forno de fusão por vácuo e atmosfera do deserto. A terceira é obter as fundições de aç...