電風(fēng)扇葉片鎖緊螺母的注射模設(shè)計(jì)【一模兩腔】【側(cè)抽芯】【說(shuō)明書+CAD+PROE】

電風(fēng)扇葉片鎖緊螺母的注射模設(shè)計(jì)【一模兩腔】【側(cè)抽芯】【說(shuō)明書+CAD+PROE】,一模兩腔,側(cè)抽芯,說(shuō)明書+CAD+PROE,電風(fēng)扇,葉片,螺母,注射,設(shè)計(jì),說(shuō)明書,仿單,cad,proe 南京理工大學(xué)泰州科技學(xué)院畢業(yè)設(shè)計(jì)(論文)外文資料翻譯系部： 機(jī)械工程系 專 業(yè)： 機(jī)械工程及自動(dòng)化 姓 名： 周峰 學(xué) 號(hào)： 05010154 (用外文寫)外文出處：WORCESTER POLYTECHNIC INSTITUTE 附 件： 1.外文資料翻譯譯文；2.外文原文。 指導(dǎo)教師評(píng)語(yǔ)：譯文比較正確地表達(dá)了原文的意義、概念描述基本符合漢語(yǔ)的習(xí)慣，語(yǔ)句較通暢，層次較清晰。翻譯質(zhì)量良。 簽名： 年 月 日注：請(qǐng)將該封面與附件裝訂成冊(cè)。附件1：外文資料翻譯譯文熱等靜壓合并過(guò)程的發(fā)展和解決鋁鑄件浸滲的熱處理過(guò)程的成本效益由于A356（7硅，鎂0.4）鋁合金鑄件的形狀復(fù)雜性和良好的強(qiáng)度重量比，在汽車行業(yè)越來(lái)越多的使用這些部件。然而，這些零件的應(yīng)用受到鑄造條件的限制，被應(yīng)用于一些機(jī)械性能較差的行業(yè)。這些較差的機(jī)械性能源于合金鑄態(tài)條件的兩個(gè)基本問(wèn)題。第一個(gè)問(wèn)題是這些鑄造合金凝固的不均勻。這種不均勻的原因是內(nèi)冷卻模具的不一致導(dǎo)致合金基體不均衡分散粗糙形成沉淀。這又導(dǎo)致在鑄態(tài)條件下產(chǎn)生較差的拉伸性能。第二個(gè)問(wèn)題是鑄態(tài)組織中所固有的孔隙度。這孔隙度分為兩個(gè)不同的種類，縮孔和氣孔的孔隙度。孔隙率是液態(tài)金屬體積大于固態(tài)金屬體積收縮所造成的。氣孔是高溶解度的液氫和鋁熔體中的氫因?yàn)闇囟冉档驼舭l(fā)所造成?？紫抖葧?huì)影響鑄造的延展性，斷裂韌性和疲勞性能。幸運(yùn)的是，在鑄造行業(yè)，這些問(wèn)題的內(nèi)在鑄條件可緩解鑄造加工。解決熱處理的其次是精煉過(guò)程，完善微觀結(jié)構(gòu)和改進(jìn)合金的機(jī)械和物理性能。浸滲可以消除鑄造中的孔隙。對(duì)鋁合金鑄件開(kāi)始加熱溶解合金基體的熱處理，稱為固溶處理，或固溶。擴(kuò)散退火采用高溫?zé)崽幚砣芙獾诙A段的沉淀物，是使初級(jí)階段改變共晶硅相的形態(tài)均勻牢固的解決辦法。如A356 ，析出的Mg2Si 。為了防止Mg2Si顆粒再次沉淀，采用快速淬火的解決方案。淬火的鑄件還能保證維持固溶步驟和結(jié)果的均勻化。為了達(dá)到最大強(qiáng)度的沉淀硬化或時(shí)效熱處理。人工時(shí)效發(fā)生在稍高溫， 165 ，而自然時(shí)效發(fā)生在室溫。均一實(shí)現(xiàn)前面的步驟確保分散的顆粒統(tǒng)一成型在時(shí)效階段。人工時(shí)效，以達(dá)到最大強(qiáng)度認(rèn)為的鑄造韌度為T6 ，而自然時(shí)效使鑄件的韌度指定T4。熱等靜壓，簡(jiǎn)稱HIP，通常是完成熱處理之前一種消除鑄件孔隙的方法。熱等靜壓是對(duì)鑄件加壓氣體，這適用于靜力表面的鑄造,升高溫度，以推動(dòng)物質(zhì)流動(dòng)。占主導(dǎo)地位的精密機(jī)器鑄造過(guò)程中是初始階段的熱等靜壓過(guò)程塑性流動(dòng)。由于鑄件長(zhǎng)時(shí)間在高溫和壓力下,使機(jī)械裝置的機(jī)制產(chǎn)生變化，首先是蠕變，然后擴(kuò)散蠕變機(jī)制（Nabarro-Herring，科布爾蠕變）?？偟男Ч恰昂附印钡墓铝⒖紫秲?nèi)的鑄造Atkinson。由于時(shí)間密集性質(zhì)的熱等靜壓過(guò)程中，一些變異的原始過(guò)程已經(jīng)制定，最大限度地返回?zé)岬褥o壓過(guò)程，同時(shí)盡量減少過(guò)程的時(shí)間和成本，是生產(chǎn)鋁鑄件的關(guān)鍵。液體熱等靜壓（LHIP）使用不可加熱的液體加壓媒體Chandley。指導(dǎo)原則在制造過(guò)程后指出，靜壓工藝大多數(shù)用于加壓和減壓空氣等可壓縮氣體。在熱等靜壓過(guò)程中，鑄件浸在鹽水和整個(gè)鹽水壓力容器通過(guò)液體沖壓非?？?。通過(guò)這種方法，最快的只要幾秒，而不是那個(gè)需要幾個(gè)小時(shí)的熱等靜壓的過(guò)程。此外，這過(guò)程可被整合成一個(gè)連續(xù)鑄造過(guò)程Chandley 。然而，最大壓力鑄造的A356在熱等靜壓過(guò)程持續(xù)約只有三十一秒Romano et al. ，它不允許任何前面所提到的蠕變機(jī)制發(fā)生。瑞達(dá)公司已采取另一種辦法來(lái)降低熱等靜壓工藝鋁鑄件的成本。該Densal過(guò)程是一個(gè)專有的熱等靜壓進(jìn)過(guò)程，專門定制的熱等靜壓工藝技術(shù)規(guī)格和硬件專門為鋁鑄件。溫度和壓力擴(kuò)散蠕變機(jī)制隨時(shí)間在變化。據(jù)估計(jì)，Densal過(guò)程降低的熱等靜壓鋁鑄件成本多達(dá)70% Mashl等 。不過(guò)，進(jìn)一步提高Densal過(guò)程經(jīng)濟(jì)性是有可能的。由于相似過(guò)程的溫度解決Mashl et al.方案熱處理和Densal 過(guò)程中，結(jié)合這兩個(gè)過(guò)程甚至可能會(huì)產(chǎn)生進(jìn)一步削減熱等靜壓及熱處理鋁鑄件的成本。這樣做的原因是制定和評(píng)估的可行性，這種合并 Densal+固溶過(guò)程。將其中包括這兩個(gè)大部分已完成的工作文件提出發(fā)表。每個(gè)文件是一個(gè)獨(dú)立的工作，摘要，引進(jìn)，程序，結(jié)果和討論，結(jié)論和參考節(jié)。第一份文件列為第2章介紹了實(shí)驗(yàn)結(jié)果相結(jié)合的過(guò)程Densal和解決熱處理對(duì)一些鋁硅鎂商業(yè)鑄件。第二份文件，第3章，介紹了成果的理論能源計(jì)算相結(jié)合過(guò)程中的個(gè)別過(guò)程Densal其次是以后的熱處理。應(yīng)用鋁鑄件的汽車行業(yè)合并熱等靜壓（HIP）/解決熱處理過(guò)程關(guān)鍵是盡量減少生產(chǎn)成本和熱處理時(shí)間。一個(gè)完整合并過(guò)程是在相同的時(shí)間和物力下，使生產(chǎn)部分單獨(dú)的生產(chǎn)過(guò)程和熱等靜壓后的熱處理提高效率。在這項(xiàng)研究中，有一個(gè)實(shí)驗(yàn)組合工藝設(shè)計(jì)和實(shí)施生產(chǎn)設(shè)施。工業(yè)生產(chǎn)鋁鑄件合并的過(guò)程，是通過(guò)拉伸和疲勞試驗(yàn)和顯微鏡檢查并量化的結(jié)果。樣品在比較疲勞和拉伸強(qiáng)度進(jìn)行了傳統(tǒng)熱等靜壓和熱處理，以及樣品在非靜壓T6條件下。結(jié)果表明：根據(jù)鑄件的疲勞性能適合獨(dú)立的熱等靜壓和熱處理工藝合并過(guò)程批量生產(chǎn)。此外，與組合工藝相比，只要鑄件制作時(shí)進(jìn)行熱處理，就能改善疲勞壽命的一個(gè)數(shù)量級(jí)。這一研究表明比較任何拉伸性能所造成的加工路線無(wú)明顯差異的。此外，微觀的比較鑄件孔隙率的加工路線以外的加工無(wú)顯著差異，這只是非熱等靜壓樣品。樹(shù)枝狀孔隙度和樹(shù)枝狀結(jié)構(gòu)的樣本，解決方案同一時(shí)間是相同的。實(shí)驗(yàn)相結(jié)合的方法也顯示這些的生產(chǎn)試驗(yàn)可以節(jié)省大量的時(shí)間。鋁鑄造是一個(gè)廉價(jià)的生產(chǎn)方法，零件形狀復(fù)雜性，優(yōu)良的強(qiáng)度重量比和良好的耐腐蝕性。由于這些原因在汽車行業(yè)鋁鑄件的使用率正在上升。但是，大多數(shù)的鋁合金鑄態(tài)條件下許多應(yīng)用上不顯示所必需的的力學(xué)性能，因此需要隨后的熱處理，以優(yōu)化合金的結(jié)構(gòu) 1 。此外，隨著越來(lái)越多地強(qiáng)調(diào)鋁鑄件的周期性應(yīng)用，如汽車懸架系統(tǒng)，最大限度地提高部件疲勞壽命的熱處理變得越來(lái)越重要。浸滲或消除鑄件內(nèi)在的孔隙度，對(duì)零件的疲勞抗性十分重要，鑄造毛孔往往是疲勞限制的原因。 2-6 。迄今為止，微觀結(jié)構(gòu)雖然通過(guò)熱處理和疲勞兩個(gè)獨(dú)立的處理方法性能的優(yōu)化致密得到完善。在大多數(shù)情況下硅鋁合金，熱處理表現(xiàn)出來(lái)的往往固溶的一步過(guò)長(zhǎng)，緊隨其后的快速淬火和隨后控制成型時(shí)間 1,7 。根據(jù)國(guó)際ASM，大多數(shù)硅鋁合金在T6條件下熱處理可以提快18 小時(shí)實(shí)現(xiàn) 1 。共晶硅新技術(shù)的改進(jìn)可以大大降低解決熱處理時(shí)間，但浸滲的步驟仍需要以改善鑄件的疲勞性能 9 。為此，熱等靜壓（HIP）前進(jìn)行熱處理工藝已被證明是一種有效的手段，增加疲勞壽命的重要應(yīng)用部分。通過(guò)消除收縮鑄造中的氣孔。與同一個(gè)非熱等靜壓樣本相比，可見(jiàn)熱等靜壓部件疲勞壽命多增加了一個(gè)數(shù)量級(jí) 2-6 。HIP過(guò)程包括鑄件與加壓氣體給予靜水壓力元件 10,11 。同時(shí)高溫高壓，使氣孔收縮或消除。初步浸滲在鑄造時(shí)通過(guò)獨(dú)立的塑性流動(dòng)開(kāi)始。然后，控制高溫和壓力的時(shí)間，通過(guò)擴(kuò)散發(fā)生蠕變機(jī)制完成浸滲 10,11 。該鏡以下顯示的影響等靜壓致密。毛孔，標(biāo)有箭頭，非熱等靜壓樣品（圖1 ）被熱等靜壓樣本（圖2 ）排除。圖1. 鑄造鋁硅鎂合金在T6條件;箭頭顯示孔隙圖2. 鑄造鋁硅鎂合金在熱等靜壓 T6條件;沒(méi)有跡象表明孔隙度目前，熱等靜壓是一個(gè)獨(dú)立的處理方法，它會(huì)增加鑄件制造成本。為了盡量減少這種鋁鑄件成本，瑞達(dá)公司已開(kāi)發(fā)出一種專利過(guò)程稱為Densal。Densal 優(yōu)化了熱等靜壓過(guò)程和鋁鑄件專門硬件，代表著降低這一過(guò)程成本的進(jìn)步6。在當(dāng)前生產(chǎn)鑄件過(guò)程中最具成本效益的的是Densal方法的應(yīng)用，其次是T6熱治療6 ，雖然Densal是一個(gè)增值過(guò)程，但仍然使用它控制時(shí)間和能量。 由于熱等靜壓周期和固溶吸收部分熱處理周期的峰值溫度相似，進(jìn)一步整合兩個(gè)過(guò)程可以節(jié)省大量的時(shí)間和能量。這一組合的提議本來(lái)就有困難。首先，由于高壓所固有的熱等靜壓的過(guò)程，快速淬火的熱等靜壓目前不可行。其次，即使晶體合金改進(jìn)，通常是熱等靜壓容器溫度保持時(shí)間不夠長(zhǎng)來(lái)完整固溶。本研究是調(diào)查的可行性相結(jié)合的商業(yè) Densal /解決熱處理的過(guò)程。為此，將制定和實(shí)施一項(xiàng)實(shí)驗(yàn)相結(jié)合的過(guò)程。其次，將進(jìn)行調(diào)查影響工業(yè)鑄件合并過(guò)程的微觀結(jié)構(gòu)和拉伸強(qiáng)度和疲勞性能。試驗(yàn)結(jié)合熱等靜壓/解決熱處理的可行性的制造程序已經(jīng)開(kāi)發(fā)出來(lái)。這一方法是改進(jìn)當(dāng)前熱等靜壓部分，完全解決熱處理的熱等靜壓容器使其能夠滿足從固溶溫度。鑄造過(guò)程中的合并過(guò)程經(jīng)過(guò)相同的獨(dú)立解決熱處理將影響鑄件表面溫度。具體來(lái)說(shuō)，鑄件的溫度將提高到溶化溫度，持續(xù)一段時(shí)間，然后通過(guò)傳統(tǒng)的水淬使溫度迅速下降。同時(shí)進(jìn)行的固溶浸滲。在同一時(shí)間提高鑄件的溫度，圍繞鑄件的氣體壓力也將上升到一定數(shù)值。這壓力保持的時(shí)間為標(biāo)準(zhǔn)Densal保壓時(shí)間，而不是對(duì)整個(gè)固溶時(shí)間。當(dāng)解決方案的溫度保持和剩余的固溶時(shí)間完成時(shí)，壓力將減少。其中有一個(gè)重要問(wèn)題需要加以解決，以確定采用熱等靜壓爐的可行性合并方法是否有足夠力量去克服該容器絕熱冷卻時(shí)壓力過(guò)大而可能產(chǎn)生的泄露?？紤]到傳熱之間的鑄件和加壓氣體, 這個(gè)問(wèn)題變得日趨重要。運(yùn)行壓力容器等靜壓加壓氣體和鑄件的傳熱比率大約是100W/m2k 12 。但是，如果能夠保持爐的鑄造固溶溫度，Tsolution,而容器內(nèi)的壓力減少，那么剩余鑄件可以在該容器開(kāi)始Tsolution。然后鑄件被轉(zhuǎn)移到浸泡爐繼續(xù)解決熱處理或在特殊情況下，水淬。參考書目1 H.V. Atkinson, S. Davies, Fundamental Aspects of Hot Isostatic Pressing: An Overview, Metallurgical and Materials Transactions A, Vol. 31A, December 2000,pp. 2981-3000.2 H.V. Atkinson, B.A. Rickinson, Hot Isostatic Processing, Adam Hilger, Bristol, UK,1991.3 Q.G. Wang, D. Apelian, D.A. Lados, Fatigue Behavior of A356-T6 Aluminum Cast Alloys. Part I. Effect of Casting Defects, Journal of Light Metals 1, 2001, pp. 73-84.4 C.S.C Lei, W.E. Frazier, E.W. Lee, The Effect of Hot Isostatic Pressing on CastAluminum, Journal Of Metals, November 1997, pp. 38-39.5 J.C. Hebeisen, B.M. Cox, J. Turonek, R. Stack, The Effect of Densal Processing on the Properties of a Cast Aluminum Steering Knuckle, SAE Technical Publication,2002.6 S.J. Mashl, J.C. Hebeisen, D. Apelian, Q.G. Wang, Hot Isostatic Pressing of A356 and 380/383 Aluminum Alloys: An Evaluation of Porosity, Fatigue Properties and Processing Costs, SAE Technical Publication #2000-01-0062.7 M.M. Diem, S. Mashl, R. Sisson, Cost Effective Densification of Critical Application Aluminum through Simultaneous Densal and Solution Heat Treatment. Part 1 Testing Industrial Castings, TBA.8 C.R. Brooks, ASM Handbook, vol. 4, ASM International, Materials Park, OH, 1991,pp. 823-879.9 S, Shivkumar, C. Keller, D. Apelian, Aging Behavior in Cast Al-Si-Mg Alloys,American Foundrymens Society Transactions, Vol. 90, No. 179, pp. 905-911.10 D. Apelian, S. Shivkumar, S. Sigworth, Fundamental Aspects of Heat Treatment of Cast Al-Si-Mg Alloys, American Foundrymens Society Transactions, vol. 89, No. 137, pp. 727-742.11 C, Bergmann, HIP Quenching in 2000 Bar Argon Gas, Metal Powder Report, October 1990, pp. 669-671.12 F.T. Wall, Chemical Thermodynamics,W. H. Freeman and Company, San Francisco , CA, 1958.附件2：外文原文（復(fù)印件）Development of a combined hot isostatic pressing andsolution heat-treat process for the cost effectivedensification of critical aluminum castingsThe use of A356 (7%Si, 0.4%Mg) aluminum castings in the automotive industry is ncreasing due to the high shape complexity and the good strength-to-weight ratios that an be obtained with these parts. However, these parts in the as-cast condition are restricted in the applications in which they can be employed due to poor mechanical properties. These poor mechanical properties stem from two fundamental issues of the alloy in the as-cast condition.The first issue with these castings is caused by inhomogeneity in the casting alloy during solidification. This non-uniformity is caused by inconsistent cooling within the mold and leads to an uneven dispersion of coarsely formed precipitates in the alloy matrix. This in turn leads to poor tensile properties in the as-cast condition.The second issue inherent in as-cast microstructure is porosity. This porosity is classified as two distinct varieties, shrinkage porosity and gas porosity. Shrinkage porosity is caused by the volume of the liquid metal being greater than the volume of the solid metal. Gas porosity is caused by the high solubility of hydrogen in the liquid aluminum melt and the tendency for the hydrogen to come out of solution as temperature is reduced. Porosity is detrimental to the ductility, fracture toughness and fatigue behavior of the casting. Fortunately, for the casting industry, the issues inherent in the as-cast condition can be alleviated with post casting processing. Solution heat treating followed by aging is employed to refine the microstructure of the alloy and improve mechanical and physical properties. A densification process can eliminate the porosity in the casting.Heat treatment for cast aluminum alloys starts with a thermal process to solutionize the alloy matrix, known as solution heat treatment, or solutionizing. Solution heat treatment uses an elevated temperature heat treatment to dissolve the second phase precipitates, change the morphology of the eutectic silicon phase and make the primary phase a homogeneous solid solution. In the case of A356, the precipitates are Mg2Si. In order to prevent the Mg2Si particulates from again precipitating out of solution, a rapid quench is employed. Quenching the castings also insures that the homogenization that results from the solutionizing step is maintained. To attain maximum strength in the casting a precipitation-hardening or aging heat treatment is employed. Artificial aging takes place at slightly elevated temperatures, 165C, while natural aging occurs at room temperature. The homogenization attained in the previous steps insures a uniform dispersion of the particulates grown in the aging step. Artificial aging to reach maximum strength deems the temper of the casting as T6, where natural aging gives the casting the temper designation T4.Hot isostatic pressing, or HIP, is typically performed before heat treatment and is a means of eliminating the porosity in castings. HIP surrounds the casting with a pressurized gas, which applies a hydrostatic force to the surface of the casting while at elevated temperature to facilitate material flow. The dominant densification mechanism in the casting during the initial stages of the HIP process is plastic flow. As castings spend additional time at maximum temperature and pressure the dominant densification mechanisms change, first to power-law creep, then to diffusional creep mechanisms (Nabarro-Herring, and Coble creep). The overall effect is the welding of isolated porosity within the casting Atkinson.Due to the time intensive nature of the HIP process, several variants of the original process have been developed to maximize the returns of the HIP process while minimizing process time and cost for the production of critical aluminum castings. Liquid hot isostatic pressing (LHIP) uses a heated incompressible liquid as the pressurizing media Chandley. The guiding principle behind this manufacturing process states that the majority of the time spent in the traditional gas HIP process is spent pressurizing and depressurizing the compressible gas media. In the LHIP process, the castings are immersed in the liquid salt bath and the entire salt bath container is pressurized via a hydraulic ram very quickly. By this method, maximum pressure can be reached in seconds rather then the several hours required in the HIP process. Furthermore, this process could be integrated into a continuous casting process Chandley. However, time spent at peak pressure for an A356 casting in the LHIP process is only about thirty seconds Romano et al., which does not allow any of the previously mentioned timedependant creep mechanisms to occur.Bodycote PLC has taken another approach to reducing the cost of the HIP process for aluminum castings. The Densal process is a proprietary HIP process that has tailored the HIP process specifications and hardware specifically for aluminum castings. Time spent at temperature and pressure allows diffusional creep mechanisms to take place. It has been estimated that the Densal process reduces the cost of HIP for aluminum castings by as much as seventy percent Mashl et al. However, further gains in Densal process economy may be possible. Due to the similarity of the process temperatures of solution heat treatment and the Densal process, integrating these two processes could yield even further reduction in the cost of HIP and heat treatment for aluminum castings.The purpose of this thesis is to develop and evaluate the feasibility of this combined Densal + solutionizing process. The bulk of the work completed is included here as two papers to be submitted for publication. Each paper is a stand-alone work with separate abstract, introduction, procedure, results and discussion, conclusion and reference sections. The first paper included as Chapter 2 presents the experimental results of the process combination of Densal and solution heat treatment on several Al-Si-Mg commercial castings. The second paper, Chapter 3, presents the results of the theoretical energy calculations of the combined process versus the individual processes of Densalfollowed by subsequent heat treatment.Aluminum casting represents an inexpensive method of producing parts with high shape complexity, excellent strength-to-weight ratios, and good corrosion resistance. For these reasons the use of aluminum castings in the automotive industry is on the rise. However, most aluminum alloys in the as-cast condition do not display the mechanical properties necessary for many applications, and therefore require subsequent heat treatment to optimize the microstructure of the alloy 1. Furthermore, with the increased use of aluminum castings in cyclically stressed applications such as automotive suspension systems, maximizing the fatigue life of the heat-treated components becomes increasingly important. Densification, or the elimination of porosity inherent in the castings, is paramount in the production of fatigue-resistant parts, as pores are most often the fatigue-limiting characteristic in the casting. 2-6. To date, microstructural refinement though heat treatment and fatigue-performance optimization through densification are completed as two independent processes.In the case of most Al-Si alloys, the heat treatment manifests itself as an often lengthy solutionizing step, followed immediately by a rapid quench and a subsequent controlled age 1,7. According to ASM International, heat treatment can take upward of eighteen hours to achieve a T6 condition for most Al-Si alloys 1. Novel techniques of eutectic silicon modification do significantly reduce the solution heat treatment time, but densification steps are still required to improve the fatigue performance of the casting 9. To this end, hot isostatic pressing (HIP) performed before the heat treatment process has proven to be an effective means of increasing the fatigue life of critical application parts by eliminating the shrinkage and gas porosities inherent in the casting. HIPed parts can see as much as an order of magnitude increase in fatigue life when compared to identical un-HIPed samples 2-6. The HIP process surrounds the castings with a pressurized gas that imparts a hydrostatic stress on the component 10,11. This compressive stress, in tandem with elevated temperature, shrinks and heals potential stress-intensifying pores. Initial densification occurs within the casting through time independent plastic flow. Then, under the conditions of time at elevated temperature and pressure, complete densification occurs via diffusional creep mechanisms 10,11. The micrographs included below show the effects of HIP densification. The pores, marked with arrows, in the un-HIPed samples (Figure 1) are eliminated in the HIPed sample (Figure 2).Figure 1 Cast Al-Si-Mg alloy in T6 condition; arrows show porosityFigure 2 Cast Al-Si-Mg alloy in HIPed T6 condition; no evidence of porosityCurrently, HIP is an independent process that increases the manufacturing cost of castings. In order to minimize this cost for aluminum castings, Bodycote PLC has developed a proprietary process known as Densal. Densaloptimizes the HIP process and hardware specifically for aluminum castings and represents an advancement in the cost reduction of this process 6. One of the most cost-effective current process for the production of critical application castings is the Densal process followed by T6 heat treatment 6, yet it remains that while Densal is a value-added process, costs in both time and energy are incurred from its use.Due to the similarity of the peak temperature in both the HIP cycle and the solutionizing soak portion of the heat treat cycle, further integration of the two processes could save significant time and energy. There are difficulties inherent in this proposed combination. First, rapid quenching from the HIP vessel is currently not feasible due to the high pressure inherent in the HIP process. Secondly, even with eutectic-modification of alloys, the time at dwell temperature in the HIP vessel is usually not long enough for complete solutionizing.The goal of this study is to investigate the feasibility of a combined commercial Densal/solution heat treat process. This will be accomplished by designing and implementing an experimental combined process. Next, the effects of the combined process on the microstructure and tensile and fatigue properties of industrial castings will be investigated.A manufacturing procedure has been developed to test the feasibility of a combined HIP/solution heat treatment. The process modifies current HIP hardware to allow full solution heat treatment in the HIP vessel as well as the ability to quench from the solutionizing temperature. The thermal profile that a casting is subjected to during the combined process will be identical to that seen by a casting undergoing the independent solution heat treatment. Specifically, the temperature of the castings will be raised to the solution temperature, maintained for a certain dwell time, and then rapidly dropped via a traditional water quench. Going on concurrently to the solutionizing however will be the densification process. At the same time as the temperature of the casting is raised, the pressure of the gaseous media surrounding the casting will also rise to a prescribed value. This pressure will be only be maintained for the length of the standard Densal dwell time and not for the entire solutionizing time. Pressure will be reduced while solution temperature is maintained and the remainder of the solutionizing time will be fulfilled.One of the major questions that needed to be addressed to determine the feasibility of this combined process was whether the HIP furnace used had the sufficient power to overcome the adiabatic cooling that occurs in the vessel when the pressurized is vented. This issue becomes increasingly important when the heat transfer between the castings and the pressurized gas is considered. The operating pressure in the HIP vessel insures that this rate of heat transfer between the pressurized gas and the castings is on the order of 100 W/m2 K 12. However, if the furnace can maintain the casting at the solutionizing temperature, Tsolution, while the pressure within the vessel is reduced, then the vessel can be opened with the castings remaining at Tsolution. This would then allow the castings to either be transferred to a soak furnace to continue the solution heat treatment or in special cases, water quenched.References1 H.V. Atkinson, S. Davies, Fundamental Aspects of Hot Isostatic Pressing: An Overview, Metallurgical and Materials Transactions A, Vol. 31A, December 2000,pp. 2981-3000.2 H.V. Atkinson, B.A. Rickinson, Hot Isostatic Processing, Adam Hilger, Bristol, UK,1991.3 Q.G. Wang, D. Apelian, D.A. Lados, Fatigue Behavior of A356-T6 Aluminum Cast Alloys. Part I. Effect of Casting Defects, Journal of Light Metals 1, 2001, pp. 73-84.4 C.S.C Lei, W.E. Frazier, E.W. Lee, The Effect of Hot Isostatic Pressing on CastAluminum, Journal Of Metals, November 1997, pp. 38-39.5 J.C. Hebeisen, B.M. Cox, J. Turonek, R. Stack, The Effect of Densal Processing on the Properties of a Cast Aluminum Steering Knuckle, SAE Technical Publication,2002.6 S.J. Mashl, J.C. Hebeisen, D. Apelian, Q.G. Wang, Hot Isostatic Pressing of A356 and 380/383 Aluminum Alloys: An Evaluation of Porosity, Fatigue Properties and Processing Costs, SAE Technical Publication #2000-01-0062.7 M.M. Diem, S. Mashl, R. Sisson, Cost Effective Densification of Critical Application Aluminum through Simultaneous Densal and Solution Heat Treatment. Part 1 Testing Industrial Castings, TBA.8 C.R. Brooks, ASM Handbook, vol. 4, ASM International, Materials Park, OH, 1991,pp. 823-879.