1 模具熱處理及其導(dǎo)向平行設(shè)計 李雄,張鴻冰,阮雪榆,羅中華,張艷 摘要: 在一系列方式中,傳統(tǒng)模具設(shè)計方法存在許多缺點。眾所周知,熱處理對模 具起著非常重要的作用。為了克服模具熱處理工藝存在的缺點,一種新的模具 熱處理工藝并行設(shè)計方法已經(jīng)被開發(fā)出來了。熱處理 CAD/CAE 技術(shù)是集成了 并行環(huán)境和有關(guān)模型而建立的。這些調(diào)查研究可以顯著提高效率,降低成本, 并保證產(chǎn)品質(zhì)量達到 R 和 D 級。 關(guān)鍵詞:模具設(shè)計;熱處理;模具 傳統(tǒng)模具設(shè)計主要是依照自身實踐經(jīng)驗或依照部分實踐經(jīng)驗,而不是制造 工藝。在設(shè)計完成之前,模具方案通常要被一次又一次的改進,于是有些缺點 便出現(xiàn),例如開發(fā)時期長,成本高和實際效果不明顯。由于對精確性、使用壽 命、開發(fā)期和費用的嚴格要求,先進的模具要求設(shè)計和制造得十分完善。因此 越來越先進的技術(shù)和創(chuàng)新方法被應(yīng)用其中,例如并行工程、敏捷制造業(yè)、虛擬 制造業(yè)、協(xié)同合作設(shè)計等。 模具的熱處理與模具設(shè)計,制造和裝配同樣重要。因為它對模具的制造裝 配和使用壽命又及其重要的影響。模具設(shè)計與制造發(fā)展十分迅速,但是熱處理 發(fā)展卻嚴重滯后它們。隨著模具工業(yè)的發(fā)展,熱處理必須保證模具有良好的制 造裝配和磨損耐熱性能。不切實際的熱處理將導(dǎo)致模具材料過硬或過軟,同時 影響模具裝配性能。傳統(tǒng)的熱處理工藝是按照設(shè)計師提出的方法和特性制作出 來的。這樣會使模具設(shè)計師和熱處理工藝師意見產(chǎn)生分歧,而模具設(shè)計師卻不 能充分地了解熱處理工藝和材料的性能,相反熱處理工藝師卻很少了解模具的 使用環(huán)境和設(shè)計思路。這些分歧將在很大程度上影響模具的發(fā)展。因此,如果 把熱處理工藝設(shè)計放在設(shè)計階段之前,則縮短開發(fā)周期,減少花費和保證質(zhì)量 等目標將會被考慮,而且從串行到并行的發(fā)展模式也將會實現(xiàn)。 并行工程是以計算機集成系統(tǒng)作為載體,在開始以后,每個階段和因素都 被看作如制造、熱處理、性能等等,以避免出現(xiàn)錯誤。并行模式已經(jīng)摒除了串 行模式的缺陷,由此帶來了一場對串行模式的革命。 在當前的工作中,熱處理被集成到了模具開發(fā)的并行環(huán)境中,同時也正在 進行這種系統(tǒng)性和深入性的研究。 1.熱處理下的并行環(huán)境 2 并行模式與串行模式存在根本的不同(見圖 1) 。對于串行模式,設(shè)計者大 多考慮的是模具的結(jié)構(gòu)與功能,但很難考慮相關(guān)的工藝,以致前者的錯誤很容 易蔓延到后面。與此同時,設(shè)計本門很少與裝配,預(yù)算會計和銷售部門溝通。 這些問題當然會影響模具的開發(fā)進度和市場前景。然而在并行模式中,不但以 上部門關(guān)系聯(lián)系密切,所有參加模具開發(fā)的部門都與買家有密切的交流。這有 助于協(xié)調(diào)各部門消除矛盾,提高工作效率,同時降低成本。 并行環(huán)境下的熱處理工藝不是在方案和工件確定以后,而是在模具設(shè)計的 時候制定出來的。這樣的話,將有利于優(yōu)化熱處理工藝,充分利用材料。 3 2.模具熱處理 CAD/CAE 一體化 從圖 2 中可以看出,熱處理工藝的設(shè)計與模擬是一體化模式的核心。在信 息輸入產(chǎn)品模塊中后,經(jīng)熱處理工藝過程產(chǎn)生的熱處理 CAD 和熱處理 CAE 模 塊將對于零件圖,熱處理以后模擬溫度場的微觀結(jié)構(gòu)分析和可能出現(xiàn)的缺陷 (例如過熱,燒傷)自動劃分網(wǎng)絡(luò),如果優(yōu)化是根據(jù)立體視覺技術(shù)的結(jié)果重新 出現(xiàn),則這項熱處理工藝已經(jīng)被審核。而且工具與夾具的 CAD 和 CAE 也集成 于這種系統(tǒng)中 以并行工程為基礎(chǔ)的集成模式可以與其它類似模式共享信息。這樣使熱處 理工藝得到優(yōu)化,并確保改工藝準確。 2.1 采用三維模型和立體視覺技術(shù)的熱處理 在形成模具的基礎(chǔ)上,材料,結(jié)構(gòu)和尺寸的問題能通過熱處理三維模型盡 快發(fā)現(xiàn)出來。在熱處理過程中,模具加熱條件和相變條件是切合實際的,因為 通過計算相變熱力、相變動力、相應(yīng)力、熱應(yīng)力、傳熱速度、流體動力等已經(jīng) 取得重要突破。例如,能進行局部復(fù)雜表面和不對稱模具的三維熱傳導(dǎo)模型計 算,和能進行微觀結(jié)構(gòu)轉(zhuǎn)變的 MARC 軟件模型。計算機能夠在任何時間提交溫 度,微觀結(jié)構(gòu)和應(yīng)力的信息,并通過連接溫度場微觀結(jié)構(gòu)領(lǐng)域和力場來顯示三 維形式的全部改變過程。如果再加上這種特性,則各部分性能都能通過計算機 4 預(yù)見。 2.2 熱處理工藝設(shè)計 由于對強度和硬度,表面粗糙度和模具熱處理變形的特殊要求,淬火介質(zhì) 的種類、淬火溫度、回火溫度和時間等參數(shù)特性必須經(jīng)過適當?shù)倪x擇,以及是 否使用表面淬火或化學(xué)熱處理,這種特性必須準確的制定下來。自從計算機技 術(shù)在最近幾十年迅速的發(fā)展,難以進行大型計算已經(jīng)成為過去。通過模擬和仔 細考慮熱處理特性,熱處理后的成本和所須時間,這些都并不難優(yōu)化熱處理工 藝。 2.3 熱處理數(shù)據(jù)庫 熱處理數(shù)據(jù)庫在圖 3 中描述。數(shù)據(jù)庫是制定熱處理工藝的基礎(chǔ)。一般來說, 熱處理數(shù)據(jù)庫分為材料數(shù)據(jù)庫和工藝數(shù)據(jù)庫。通過材料和工藝來預(yù)測特性已成 為一種必然的趨勢。盡管很難建立一個特性數(shù)據(jù)庫,但通過一系列的測試來建 立數(shù)據(jù)庫是必要的。材料數(shù)據(jù)庫包括材料牌號、化學(xué)成分、性能和國內(nèi)外同級 別目錄表。工藝數(shù)據(jù)庫包括熱處理標準、種類、保溫時間和冷卻溫度?;跀?shù) 據(jù)庫,熱處理工藝可以通過推理規(guī)則創(chuàng)造出來。 2.4 熱處理工具和設(shè)備 在熱處理工藝確定以后,工具及設(shè)備 CAD/CAE 系統(tǒng)傳送設(shè)計和制造的數(shù) 值信息來控制裝置。通過快速模具成型,可靠的工具和夾具都能被確定。整個 程序通過網(wǎng)絡(luò)傳送,不存在任何人為干擾。 3.關(guān)鍵技術(shù) 5 3.1 溫度,微觀結(jié)構(gòu),應(yīng)力和特性的聯(lián)系 熱處理程序是一個溫度,微觀結(jié)構(gòu)和應(yīng)力互相作用的程序。三方面都能影 響材料特性(見圖 4) 。在加熱和冷卻期間,當微觀結(jié)構(gòu)轉(zhuǎn)變時熱應(yīng)力和相變遲 早會出現(xiàn)。微觀結(jié)構(gòu)溫度相變和溫度-微觀結(jié)構(gòu)-應(yīng)力特性相互影響。對相互 作用的四個因素的調(diào)查已經(jīng)取得很大的發(fā)展,但普通的數(shù)學(xué)模型還沒有建立。 許多模型能很好的滿足測試結(jié)果,但不能投入到實踐當中。大部分模型的難點 是用分析的方法處理的,同時數(shù)值方法也運用了,導(dǎo)致存在不準確的計算 。 圖 4.熱處理工藝圖解 即使如此,把經(jīng)驗方法與定性分析相比較,通過計算機來進行熱處理模擬 取得了很大的進展。 3.2 模型的建立和融合 在模具的開發(fā)過程中,涉及到設(shè)計、制造、熱處理、裝配、維修等。它們 應(yīng)該有自己的數(shù)據(jù)庫和模型。它們通過事物的內(nèi)在聯(lián)系建立模型,互相串聯(lián)起 來,盡管建立和運用動態(tài)推理機制,但其目的在于完成優(yōu)化設(shè)計。產(chǎn)品模型和 其它模型的聯(lián)系已被建立。如果細小組織模型發(fā)生改變,則產(chǎn)品模型也將改變。 事實上,它屬于數(shù)據(jù)庫與模具之間的聯(lián)系。當熱處理模型集成到系統(tǒng)以后,它 已不再是一個孤立的單位,而是一個部分,同時在系統(tǒng)中接近其它模型。在搜 查后,熱處理數(shù)據(jù)庫的計算和推理能力,熱處理程序都被幾何模型,模具制造 模型和預(yù)算所限制,這是通行的。如果這種限制不服從,系統(tǒng)會發(fā)出解釋性的 警告。 所用設(shè)計的細小組織都是通過互連網(wǎng)連接的。 3.3 各部分之間的管理和協(xié)調(diào) 復(fù)雜的模具需要其中各項目組之間密切合作。因為考慮到模具的開發(fā),各 6 部分都存在缺點,它必須得到管理和協(xié)調(diào)。首先,各項目組應(yīng)該確定其本身的 控制條件和資源要求,同時了解不同環(huán)境下的工作程序,以避免發(fā)生沖突。其 次,要提出開發(fā)計劃和建立監(jiān)控機制。如果開發(fā)受到限制則可逐步排除。 敏捷管理和協(xié)調(diào)有助于交流信息,提高效率和減少材料。同時這有利于激 發(fā)人的創(chuàng)造力,消除阻礙和制定出最好的方法。 4.總結(jié) ⑴熱處理 CAD/CAE 技術(shù)已被集成到模具并行設(shè)計中去,同時熱處理已被 制成圖表,這有利于提高效率,較易發(fā)現(xiàn)問題并解決問題。 ⑵模型的開發(fā)已在同一個平臺運行。在這個平臺中,當熱處理工藝制定出 來后,設(shè)計人員可獲得相關(guān)信息和轉(zhuǎn)讓部分信息到其它設(shè)計部門。 ⑶制定出正確的開發(fā)計劃并按時調(diào)整可以極大縮短開發(fā)周期和降低成本。 文獻出處: 李雄,張鴻冰,阮雪榆,羅中華,張艷.模具熱處理及其導(dǎo)向平行設(shè)計[J]. 鋼鐵研究學(xué)報 英文版,2006,13(1):40-43,74 Heat Treatment of Die and Mould Oriented Concurrent Design LI Xiong,ZHANG Hong-bing,RUAN Xue—yu,LUO Zhong—hua,ZHANG Yan Abstract: Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment process of die and mould was developed in order to overcome the existent shortcomings of heat treatment process. Heat treatment CAD/CAE was integrated with concurrent circumstance and the relevant model was built. These investigations can remarkably improve efficiency, reduce cost and ensure quality of R and D for products. Key words:die design; heat treatment; mould Traditional die and mould design,mainly by experience or semi—experience,is isolated from manufacturing process.Before the design is finalized,the scheme of die and mould is usually modified time and again, thus some disadvantages come into being,such as long development period,high cost and uncertain practical effect.Due to strong desires for precision,service life,development period and cost,modern die and mould should be designed and manufactured perfectly.Therefore more and more advanced technologies and innovations have been applied,for example,concurrent engineering,agile manufacturing virtual manufacturing,collaborative design,etc. Heat treatment of die and mould is as important as design,manufacture and assembly because it has a vital effect on manufacture,assembly and service life.Design and manufacture of die and mould have progressed rapidly,but heat treatment lagged seriously behind them.As die and mould industry develops,heat treatment must ensure die and mould there are good state of manufacture,assembly and wear—resistant properties by request. Impertinent heat treatment can influence die and mould manufacturing such as over—hard and—soft and assembly.Traditionally the heat treatment process was made out according to the methods and properties brought forward by designer. This could make the designers of die and mould and heat treatment diverge from each other,for the designers of die and mould could not fully realize heat treatment process and materials properties,and contrarily the designers rarely understood the service environment and designing thought. These divergences will impact the progress of die and mould to a great extent. Accordingly,if the process design of heat treatment is considered in the early designing stage,the aims of shortening development period,reducing cost and stabilizing quality will be achieved and the sublimation of development pattern from serial to concurrent will be realized. Concurrent engineering takes computer integration system as a carrier,at the very start subsequent each stage and factors have been considered such as manufacturing,heat treating,properties and so forth in order to avoid the error.The concurrent pattern has dismissed the defect of serial pattern,which bring about a revolution against serial pattern. In the present work.the heat treatment was integrated into the concurrent circumstance of the die and mould development, and the systemic and profound research was performed. 1 Heat Treatment Under Concurrent Circumstance The concurrent pattern differs ultimately from the serial pattern(see Fig.1). With regard to serial pattern,the designers mostly consider the structure and function of die and mould,yet hardly consider the consequent process,so that the former mistakes are easily spread backwards.Meanwhile,the design department rarely communicates with the assembling,cost accounting and sales departments. These problems certainly will influence the development progress of die and mould and the market foreground.Whereas in the concurrent pattern,the relations among departments are close,the related departments all take part in the development progress of die and mould and have close intercommunion with purchasers.This is propitious to elimination of the conflicts between departments, increase the efficiency and reduce the cost. Heat treatment process in the concurrent circumstance is made out not after blueprint and workpiece taken but during die and mould designing.In this way,it is favorable to optimizing the heat treatment process and making full use of the potential of the materials. 2 Integration of Heat Treatment CAD/CAE for Die and Mould It can be seen from Fig.2 that the process design and simulation of heat treatment are the core of integration frame.After information input via product design module and heat treatment process generated via heat treatment CAD and heat treatment CAE module will automatically divide the mesh for parts drawing,simulation temperature field microstructure analysis after heat—treatment and the defect of possible emerging (such as overheat,over burning),and then the heat treatment process is judged if the optimization is made according to the result reappeared by stereoscopic vision technology.Moreover tool and clamping apparatus CAD and CAM are integrated into this system. The concurrent engineering based integration frame can share information with other branch. That makes for optimizing the heat treatment process and ensuring the process sound. 2.1 3-D model and stereoscopic vision technology for heat treatment The problems about materials,structure and size for die and mould can be discovered as soon as possible by 3-D model for heat treatment based on the shape of die and mould.Modeling heating condition and phase transformation condition for die and mould during heat treatment are workable,because it has been broken through for the calculation of phase transformation thermodynamics,phase transformation kinetics,phase stress,thermal stress,heat transfer,hydrokinetics etc.For example,3-D heat—conducting algorithm models for local heating complicated impression and asymmetric die and mould,and M ARC software models for microstructure transformation was used.Computer can present the informations of temperature,microstructure and stress at arbitrary time and display the entire transformation procedure in the form of 3-D by coupling temperature field,microstructure field and stress field.If the property can be coupled,various partial properties can be predicted by computer. 2.2 Heat treatment process design Due to the special requests for strength,hardness,surface roughness and distortion during heat treatment for die and mould,the parameters including quenching medium type, quenching temperature and tempering temperature and time,must be properly selected,and whether using surface quenching or chemical heat treatment the parameters must be rightly determined.It is difficult to determine the parameters by computer fully.Since computer technology develops quickly in recent decades,the difficulty with large—scale calculation has been overcome.By simulating and weighing the property,the cost and the required period after heat treatment.it is not difficult to optimize the heat treatment process. 2.3 Data base for heat treatment A heat treatment database is described in Fig. 3.The database is the foundation of making out heat treatment process.Generally,heat treatment database is divided into materials database and process database.It is an inexorable trend to predict the property by materials and process.Although it is difficult to establish a property database,it is necessary to establish the database by a series of tests.The materials database includes steel grades,chemical compositions,properties and home and abroad grades parallel tables.The process database includes heat treatment criterions,classes,heat preservation time and cooling velocity.Based on the database,heat treatment process can be created by inferring from rules. 2.4 Tool and equipment for heat treatment After heat treatment process is determined,tool and equipment CAD/CAE system transfers the information about design and manufacture to the numerical control device.Through rapid tooling prototype, the reliability of tool and the clamping apparatus can be judged.The whole procedure is transferred by network,in which there is no man—made interference. 3 Key Technique 3.1 Coupling of temperature,microstructure,stress and property Heat treatment procedure is a procedure of temperature-microstructure—stress interaction.The three factors can all influence the property (see Fig.4) .During heating and cooling,hot stress and transformation will come into being when microstructure changes.Transformation temperature-microstructure and temperature—microstructure—and stress-property interact on each other.Research on the interaction of the four factors has been greatly developed,but the universal mathematic model has not been built.Many models fit the test nicely,but they cannot be put into practice.Difficulties with most of models are solved in analytic solution,and numerical method is employed so that the inaccuracy of calculation exists. Even so,comparing experience method with qualitative analysis,heat treatment simulation by computer makes great progress. 3.2 Establishment and integration of models The development procedure for die and mould involves design,manufacture,heat treatment,assembly,maintenance and so on.They should have own database and mode1.They are in series with each other by the entity—relation model.Through establishing and employing dynamic inference mechanism , the aim of optimizing design can be achieved.The relation between product model and other models was built.The product model will change in case the cell model changes. In fact,it belongs to the relation of data with die and mould.After heat treatment model is integrated into the system,it is no more an isolated unit but a member which is close to other models in the system.After searching,calculating and reasoning from the heat treatment database,procedure for heat treatment,which is restricted by geometric model,manufacture model for die and mould and by cost and property,is obtained. If the restriction is disobeyed, the system will send out the interpretative warning. All design cells are connected by communication network. 3.3 Management and harmony among members The complexity of die and mould requires closely cooperating among item groups.Because each member is short of global consideration for die and mould development, they need to be managed and harmonized.Firstly,each item group should define its own control condition and resource requested,and learn of the request of up-and-down working procedure in order to avoid conflict.Secondly,development plan should be made out and monitor mechanism should be established.The obstruction can be duly excluded in case the development is hindered. Agile management and harmony redound to communicating information, increasing efficiency,and reducing redundancy.Meanwhile it is beneficial for exciting creativity,clearing conflict and making the best of resource. 4 Conclusions (1) Heat treatment CAD/ CAE has been integrated into concurrent design for die and mould and heat treatment is graphed,which can increase efficiency,easily discover problems and clear conflicts. (2) Die and mould development is performed on the same platform.When the heat treatment process is made out,designers can obtain correlative information and transfer self-information to other design departments on the platform. (3) Making out correct development schedule and adjusting it in time can enormously shorten the development period and reduce cost. References: [1] ZHOU Xiong-hui,PENG Ying-hong.The Theory and Technique of Modern Die and Mould Design and Manufacture[M].Shanghai:Shanghai Jiaotong University Press 2000(in Chinese). [2] Kang M,Park& Computer Integrated Mold Manufacturing[J].Int J Computer Integrated Manufacturing,1995,5:229-239. [3] Yau H T, Meno C H.Concurrent Process Planning for Finishing Milling and Dimensional Inspection of Sculptured Surface in Die and Mould Manufacturing[J].Int J Product Research,1993,31(11):2709—2725. [4] LI Xiang,ZHOU Xiong-hui,RUAN Xue-yu.Application of Injection Mold Collaborative Manufacturing System [J].JournaI of Shanghai Jiaotong University,2000,35(4) : 1391-1394. [5] Kuzman K,Nardin B,Kovae M ,et a1.The Integration of Rapid Prototyping and CAE in Mould Manufacturing [J].J Materials Processing Technology,2001,111: 279—285. [6] LI Xiong,ZHANG Hong—bing,RUAN Xue-yu,et a1.Heat Treatment Process Design Oriented Based on Concurrent Engineering[J].Journal of Iron and Steel Research,2002,14(4):26—29. 文獻出處: LI Xiong,ZHANG Hong-bing,RUAN Xue—yu,LUO Zhong—hua,ZHANG Yan. Heat Treatment of Die and Mould Oriented Concurrent Design[J]. Journal of Iron and Steel Research,2006,13(1): 40-43,74