通過砂鑄壓鑄和離心鑄造技術對Al C355.0的力學表征和顯微組織分析【中文2700字】【PDF+中文WORD】,中文2700字,PDF+中文WORD,通過砂鑄,壓鑄和離心鑄造技術對Al,C355.0的力學表征和顯微組織分析【中文2700字】【PDF+中文WORD】,通過,壓鑄,離心,鑄造,技術,Al,C355,力學 【中文2762字】 AMMMT 2016 通過砂鑄，壓鑄和離心鑄造技術對Al C355.0的力學表征和顯微組織分析 Santosh M V *，Suresh K R，Kiran Aithal S 印度卡納塔克邦班加羅爾NMIT機械工程系 摘要 在這項研究中，研究了鋁合金C355.0的力學性能用于砂鑄，壓鑄和離心鑄造技術。采用PC2000軟件進行拉伸試驗等力學性能測試，并進行布氏硬度試驗。觀察到壓鑄與砂和離心鑄件相比具有良好的拉伸和硬度性能。使用具有Clemax圖像分析儀的Nikon Microscope LV150進行微結構分析。從觀察壓鑄件的硅分布均勻。使用滑動磨損試驗研究的合金的磨損行為。在所有鑄件中發(fā)現(xiàn)了良好的磨損比磨損率，但在20N負荷下的壓鑄中觀察到了最好的磨損率。 關鍵詞：壓鑄;砂模鑄造;離心鑄造;機械和滑動磨損性能。 1.簡介 鋁質輕，強度高，是汽車和航空航天工業(yè)中的重要金屬。一般純鋁不符合行業(yè)標準，因此，它們與硅，銅，鎂等許多金屬合金化，以提高鋁的強度等性能，其中Al-Si-Cu-Mg合金系統(tǒng)就是其中之一。 Al-Si-Cu-Mg系由于具有優(yōu)異的鑄造性和機械性能，是工業(yè)中使用最多的合金族。應用從航空航天到汽車到家庭工業(yè)。所以這個合金系在其中一個合金C355.0是非常重要的。主要的合金成分是硅和銅，硅含量的增加會增加合金的硬度系統(tǒng)和增加銅強度（產量和最終）增加[1-10,13]。隨著載荷和滑動距離的增加，體積損失增加，但滑動距離的摩擦系數不變，而摩擦系數隨著滑動距離的增加而減小[11,12]。 在本文中，試圖比較一般在重力鑄造，砂鑄等行業(yè)中使用的不同鑄造技術的機械特性。另外，由于在汽車工業(yè)中摩擦磨損起著重要作用，滑動磨損行為也被分析。 2.材料 表1中示出了鋁合金C355.0的化學成分。鋁的特性如表2所示。鋁具有FCC晶體結構，晶格參數a = 0.405nm，原子半徑R = 0.143nm。鋁C355.0是一種亞共晶合金，因為％wt。的硅小于12％。 表1 C355.0合金的化學組成，％wt。 元素 ％wt。 銅 1.32 鎂 0.34 硅 5.05 鐵 0.15 錳 0.01 倪 0.02 鋅 0.01 鉛 0.01 錫 0.01 銻 <0.01 其他（合計） 0.05 鋁 93.05 表2鋁的性質 屬性 值 密度 2.67克/CC3 熔點 557-613℃ 彈性模量 72.4GPa 泊松比 0.33 3.方法 3.1鑄造技術 合金的制造是在三種鑄造技術中進行的，即重力鑄造，砂鑄和離心鑄造。在石墨坩堝中將合金熔化至800℃。對于重力鑄造，使用直徑12mm高度為25mm的模具。在直徑12mm，高度15mm的砂型鑄造模具中澆注熔融金屬，得到鑄件。在離心鑄造中，獲得外徑60mm和高度120mm的圓柱體。 3.2 微觀結構研究 通過使用220,400,600和1000級紙對表面進行蝕刻，并用Keller's溶液（即50％H 2 O中的0.5％HF）進一步拋光來制備用于顯微結構研究的表面。使用具有Clemex圖像分析儀的Nikon Microscope LV150觀察。 3.3拉伸測試 使用的張力計由直流伺服電機運行，并配有PC2000軟件。根據ASTM E8標準，從所獲得的鑄件拉伸樣品進行加工。尺寸為直徑6.25mm，標距25mm，總長50mm。 3.4耐磨測試 根據ASTM G99標準加工磨損試樣。干滑動磨損試驗在室溫下進行不同的負荷條件。直徑為10毫米，長度為30毫米。表面用600等級的紙進行蝕刻以符合調查中使用的銷盤裝置的標準。 3.5 硬度測試 使用負荷250kg-f，壓痕球直徑10mm的布氏硬度設備進行硬度測試30秒。在行進顯微鏡和BHN測量的表面上進行壓痕，通過測量的壓痕計算。 4.結果和討論 4.1微觀結構評估 4.1.1鑄造 在壓鑄中，硅顆粒在主相中均勻分布并且發(fā)現(xiàn)α-Al基體。圖1顯示了所獲得的鑄態(tài)的未蝕刻表面。由于冷卻速度較快且均勻，所以枝晶尺寸和枝晶臂間距較小，如圖2所示。 圖1 100X時壓鑄件的未腐蝕表面 圖2在100X下壓鑄的Keller蝕刻表面。 4.1.2砂模鑄造 圖3顯示了砂鑄技術的未蝕刻表面。從圖4的觀察，黑點是鑄造過程中存在的孔隙和雜質。從圖。從圖4可以看出，樹枝狀和樹枝狀間距很小。無花果的調查。圖4時發(fā)現(xiàn)α-Al基體的固溶體和β-Si的金屬間二次相。對于Cu濃度的變化，觀察到β-Si相為大片狀，針狀和纖維狀析出物。由于存在硅針，所以會出現(xiàn)切口，從而降低機械性能。 圖3砂型鑄件在100X時的未腐蝕表面。 圖4在100X的沙子鑄件的Keller's蝕刻表面。 4.1.3離心鑄造 圖中顯示了離心鑄造的孔隙率。5.硅在主相中分布不均勻。與α-Al基體一起在第二相中形成大量的。由于存在硅針，所以會出現(xiàn)切口，從而降低機械性能。圖6中的黑點顯示散落的鎂。 圖5 100X離心鑄造的未腐蝕表面。 圖6在100X離心鑄造的Keller刻蝕表面。 4.2硬度測試 圖7硬度測試 通過測量在表面上制造的壓痕直徑來計算BHN。平均采取了三個縮進，并顯示圖。 圖7.離心鑄造具有高的硬度，因為與4.3節(jié)所示的具有良好延展性的硬度最低的壓鑄相比，發(fā)現(xiàn)它具有延性 4.3拉伸測試 圖8顯示了制造的鑄件強度的變化。最好的強度是在重力鑄造中獲得，在離心鑄造中最差。硅的均勻分布和較少的雜質和良好的鑄造工藝增加了強度，而孔隙度，離心鑄造中存在的氣孔強度最低。另一方面，在砂型鑄造多孔性方面，鑄造工藝不良，硅針的存在會造成缺口效應，強度適中。試樣的伸長率如圖2所示。 9.壓鑄工程極限強度比離心鑄造好57％，砂鑄件47％。 圖8拉伸測試 圖9％樣品的伸長率 4.4 磨損測試 無論在砂和離心鑄造中的負載如何，具體的磨損率保持恒定?；瑒泳嚯x為2500m，滑動速度為763rpm，10min，軌道直徑為100mm，磨損試驗正常載荷為10N，20N，30N。圖10顯示了鋁C355.0的比磨損率。從圖10可以看出，具體的磨損率隨著載荷的增加而降低。 圖10比磨損率 5.結論 從對鑄造技術的調查得出如下結論： ·顯微組織的評估表明，在鑄造過程中，細小的共晶硅分散在枝晶間區(qū)域，合金元素在鋁固溶體中細化析出。在砂和離心鑄造方法中發(fā)現(xiàn)了分散在樹突間區(qū)域的針。 ?壓鑄件的最低硬度為74HB，砂型鑄件的最低硬度為53HB。離心鑄造69HB具有良好的硬度。 ·工程應力為212MPa時，使用壓鑄法得到的Al C355.0的強度最好。 ·與砂和離心鑄造相比，鑄造比具有良好的比磨損率。具體磨損率隨著負載的增加而減小。 總的來說，最好的鑄造方法是壓鑄，具有良好的強度和耐磨性。即使在大批量生產的較長時間內用于制造模具的初始成本高，壓鑄也是有利的。 6.致謝 我們感謝印度班加羅爾Nitte Meenakshi技術研究所的負責人和管理人員H.C.Nagaraj博士在研究所的激勵和提供研究設施。 參考文獻 1.Zren，M.（2005）。銅和硅含量對Al - Cu - Si - Mg合金力學性能的影響，169,292-298。 http://doi.org/10.1016/j.jmatprotec.2005.03.009 2.Labisz，K.，Krupiński，M.，＆Dobrzański，L.A。（2009）。 Al-Si-Cu合金的相形態(tài)和分布，37（2），309-316。 3.Elmadagli，M.，Perry，T.，＆Alpas，A.T。（2007）。 Al - Si合金組織與耐磨性關系的參數研究，262,79-92。 http://doi.org/10.1016/j.wear.2006.03.043 4.Dwivedi，S.P。，Sharma，S.，＆Mishra，R.K。（2014）。先進材料A356鋁合金和應用 - 審查，4（2），81-86。 -5.F Czerwinski，S.K Shaha，W.Kasprzak，J.Friedman和D.L.陳（2016）。過渡金屬Zr，V和Ti改性的Al-Si-Cu-Mg鑄造合金的時效特性，012031. http://doi.org/10.1088/1757-899X/117/1/012031 6.Kasprzak，W.，Czerwinski，F(xiàn).，Niewczas，M.，＆Chen，D.L。（2015）。航空航天應用的Al和Mg鑄造合金的硬度保持和相變相關，24（3月），1365-1378。 http://doi.org/10.1007/s11665-015-1392-6 7.Wierzbińska，M.，＆Sieniawski，J.（2006）。共晶硅晶體的形態(tài)對AlSi5Cu1合金力學性能和解理斷裂韌性的影響，14（1），31-36。 8.G. Mrówka-Nowotnik，J. Sieniawski（2011）。 C355.0鑄造鋁合金的組織與力學性能。 9.R. Molina，P. Amalberto，M. Rosso。用于高溫應用的鋁合金的機械表征。第1部分：Al-Si-Cu合金。 10.LA. Dobrzański，R Maniara，M.Krupiński，J.H.索科洛夫斯基（2007年）。 AC AlSi9CuX合金的組織與力學性能。 11. Alireza Hekmat-Ardakan，Xixun Liu，F(xiàn)rank Ajersch，X-Grant Chen（2010）。 Mg含量可變的過共晶Al-Si-Cu-Mg鑄造合金的磨損行為。 12.Balasubramanya H.S，J. Sharana Basavraja，S. Srinivas，Ravi Kumar。 V（2014）。鑄態(tài)和熱處理的復合鋁基復合材料的磨損率行為。 13.G. Mrówka-Nowotnik（2008）。金屬間化合物對AlSi1MgMn合金斷裂機制的影響，30（1），35-42。 Available online at ScienceDirect Materials Today:Proceedings 4(2017)1098710993 2214-7853 2017 Elsevier Ltd.All rights reserved.Selection and Peer-review under responsibility of Advanced Materials,Manufacturing,Management and Thermal Science(AMMMT 2016).AMMMT 2016 Mechanical Characterization and Microstructure analysis of Al C355.0 by Sand Casting,Die Casting and Centrifugal Casting Techniques.Santosh M V*,Suresh K R,Kiran Aithal S Department of Mechanical engineering,NMIT Bangalore,Karnataka,India Abstract In this study,mechanical properties of aluminium alloy C355.0 was investigated for Sand Casting,Die Casting and Centrifugal Casting Technique.Mechanical properties like tensile test was performed using PC2000 software,and Brinell hardness test was performed.Die casting was observed to have good tensile and hardness properties compared to sand and centrifugal castings Microstructure analysis was done by Nikon Microscope LV150with Clemax Image Analyser.From the observation die casting had uniform distribution of silicon.Wear behavior of the alloy studied using sliding wear test.Good wear specific wear rate was found in all the casting but the best was observed in die casting at 20N load.2017 Elsevier Ltd.All rights reserved.Selection and Peer-review under responsibility of Advanced Materials,Manufacturing,Management and Thermal Science(AMMMT 2016).Keywords:Die casting;sand casting;centrifugal casting;mechanical and sliding wear properties.1.Introduction Aluminum is light and possesses high strength it is an important metal in automotive and aerospace industries.Generally pure aluminum does not fit the standards of the industries,therefore,they are alloyed with silicon,copper,magnesium and many other metals to increase strength and other properties on the aluminum among them Al-Si-Cu-Mg alloy system is one them.Al-Si-Cu-Mg system is the most used alloy group in the industries because of excellent castability and mechanical properties.The applications are from aerospace to automobile to household industries.Therefore this alloy system is very important among them C355.0 in one the alloy.The main alloying ingredient are silicon and copper,the increase in silicon content will increase the hardness of the alloy *Corresponding author.Tel.:+91-948-118-8859;E-mail address: 10988 Santosh M V/Materials Today:Proceedings 4(2017)1098710993 system and increase in copper upto strength(yield and ultimate)increased1-10,13.Also with the increase in load and sliding distance volume loss increased but friction co-efficient was constant for the sliding distance,but also friction co-efficient diminishes with longer sliding distance11,12.In this paper,an attempt is made to compare mechanical characteristics of different casting techniques that are generally used in industries namely gravity die casting,sand casting.Also since in automotive industries friction wear plays an important role sliding wear behavior are also analyzed.2.Materials The chemical composition of aluminum alloy C355.0 is shown in the Table 1.Properties of Aluminum are shown Table 2.Aluminum has a FCC crystal structure with lattice parameters a=0.405nm and atomic radius R=0.143nm.Aluminum C355.0 is a hypoeutectic alloy because%wt.of silicon is less than 12%.Table 1 Chemical Composition of C355.0 alloy,%wt.Elements%wt.Cu 1.32 Mg 0.34 Si5.05 Fe 0.15 Mn 0.01 Ni 0.02 Zn 0.01 Pb 0.01 Sn 0.01 Ti0.01 Other(Total)0.05 Al 93.05 Table 2 Properties of Aluminum Properties Values Density2.67g/cc3Melting Point 557-613C Elastic Modulus 72.4GPa Poissons Ratio 0.33 3.Methodology 3.1.Casting Techniques Fabrication of the alloy was carries out in three casting techniques namely gravity die casting,sand casting and centrifugal casting.The alloy was melted to 800C in a graphite crucible.For gravity die casting a die of diameter 12mm height of 25mm was used.In sand casting mold with diameter 12mm and height of 15mm was prepared and molten metal was poured to obtain casting.In centrifugal casting a cylinder was obtained of outside diameter 60mm and height 120mm.3.2.Microstructure Study The surface for microstructure study was prepared by etching a surface using 220,400,600,and 1000 grade papers and further polished by Kellers solution i.e.,0.5%of HF in 50ml of H2O.It was observed using Nikon Microscope LV150 with Clemex Image Analyser.Santosh M V/Materials Today:Proceedings 4(2017)1098710993 10989 3.3.Tensile Test The tensometer used was run by DC servo motors and accompanied with PC2000 software.From the obtained casting tensile specimen were machined according to ASTM E8 standards.The dimensions are gauge diameter 6.25mm and gauge length of 25mm with overall length 50mm.3.4.Wear Test Wear specimen were machined according to ASTM G99 standards.Dry sliding wear test was conducted different load conditions at room temperature.The diameter was of 10mm and length 30mm.The surface etched with 600 grade paper to fit standards of the pin-on-disc apparatus used in the investigation.3.5.Hardness Test Hardness test was conducted using Brinell Hardness Equipment with load 250kg-f with indentation ball diameter 10mm was applied for 30sec.The indentation was made on the surface which as measured by traveling microscope and BHN was calculated by the measured indentations.4.Results and Discussions 4.1.Microstructure Evaluation 4.1.1.Die Casting In die casting the silicon particles are uniform distributed among the primary phase and-Al matrix is found.Fig.1 shows the un-etched surface of the as-cast obtained.The size of dendrite size and inter-dendrite arm spacing is small because of faster and uniform cooling rate as shown in fig.2.Fig.1 Unetched surface of Die Casting at 100X.Fig.2 Kellers etched surface of Die Casting at 100X.4.1.2.Sand Casting The fig.3 shows the un-etched surface of the sand casting technique.From the observation of fig 4 the dark dots are the existence of the porosity and impurities during casting process.From fig.4 it is observed that the dendritic and inter-dendrite space is small.The investigation of fig.4 the solid solution of-Al matrix is found and an intermetallic secondary phase of-Si.The-Si phase is observed as large flakes,needles and fibrous precipitations 10990 Santosh M V/Materials Today:Proceedings 4(2017)1098710993 for the variation of Cu concentration.Since the Si needles exist there are chances of notching to occur which decreases the mechanical properties.Fig.3 Unetched surface of Sand Casting at 100X.Fig.4 Kellers etched surface of Sand Casting at 100X.4.1.3 Centrifugal Casting Porosity in centrifugal casting is shown in the fig.5.The silicon is unevenly distributed in the primary phase.A large amount of Al2Cu is formed in the secondary phase along with-Al matrix.Since the Si needles exist there are chances of notching to occur which decreases the mechanical properties.The dark spots in fig.6 shows scattered magnesium.Fig.5 Unetched surface of Centrifugal Casting at 100X.Fig.6 Kellers etched surface of Centrifugal Casting at 100X.Santosh M V/Materials Today:Proceedings 4(2017)1098710993 10991 4.2 Hardness Test Fig.7 Hardness Test BHN was calculated by measuring the indentation diameter which was made on the surface.An average was taken of three indentations and shown fig.7.Centrifugal casting had high hardness because it was found to be ductile in nature when compared to die casting which had least hardness which good ductile property as shown in section 4.3.4.3 Tensile Test Fig.8 shows the variation in the strength of castings fabricated.Best strength was obtained in gravity die casting and worst in centrifugal casting.Uniform distribution of silicon and less impurities and good casting techniques increased the strength,whereas,porosity,blowholes present in centrifugal casting had least strength.On the other hand,in sand casting porosity,bad casting technique and the presence of silicon needles which causes notching effect had moderate strength.The%elongation of the specimen is shown in fig.9.The engineering ultimate strength of die casting was better by 57%compared to centrifugal casting and by 47%to that of sand casting.Fig.8 Tensile Test 10992 Santosh M V/Materials Today:Proceedings 4(2017)1098710993 Fig.9%Elongation of the specimen 4.4.Wear Test Specific wear rate remains constant irrespective of load in sand and centrifugal casting.The sliding distance used is 2500m with sliding speed of 763rpm for 10min with track diameter of 100mm and wear test normal load was conducted for 10N,20N and 30N.Fig 10 shows the specific wear rate of aluminum C355.0.From fig.10 it can be observed that specific wear rate reduces for increases in load.Fig.10 Specific wear rate 5.Conclusion From the investigation on the casting techniques following conclusion was drawn:Microstructure evaluation showed that in die casting fine eutectic silicon dispersed in the inter-dendritic region and fine precipitation of alloy elements in Al solid solution.In sand and centrifugal casting method needles dispersed in the inter-dendritic region was found.Best hardness of 74HB was found in die casting and least 53HB in sand casting.Centrifugal casting had a good hardness with 69HB.Strength of Al C355.0 was best obtained using die casting method where engineering stress was found to be 212MPa.Santosh M V/Materials Today:Proceedings 4(2017)1098710993 10993 Die casting had good specific wear rate compared to sand and centrifugal casting.Also specific wear rate decreases with increases in load.Overall best casting method is die casting which provides good strength and wear properties.Even with high initial cost for the manufacture of the die on the longer run for mass production die casting is favorable.6.Acknowledgement We thank Dr.H.C.Nagaraj,Principal and Management of Nitte Meenakshi institute of Technology,Bangalore,India for motivating and providing research facilities at the institute.References 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