空調(diào)墊片沖壓成形工藝及模具設(shè)計【沖孔落料復(fù)合?！俊菊f明書+CAD】

空調(diào)墊片沖壓成形工藝及模具設(shè)計【沖孔落料復(fù)合?！俊菊f明書+CAD】,沖孔落料復(fù)合模,說明書+CAD,空調(diào)墊片沖壓成形工藝及模具設(shè)計【沖孔落料復(fù)合模】【說明書+CAD】,空調(diào),墊片,沖壓,成形,工藝,模具設(shè)計,沖孔,復(fù)合,說明書,仿單,cad 河南機電高等?？茖W(xué)校學(xué)生畢業(yè)設(shè)計（論文）中期檢查表學(xué)生姓名學(xué) 號指導(dǎo)教師選題情況課題名稱空調(diào)墊片沖壓成形工藝及模具設(shè)計難易程度偏難適中偏易工作量較大合理較小符合規(guī)范化的要求任務(wù)書有無開題報告有無外文翻譯質(zhì)量優(yōu)良中差學(xué)習(xí)態(tài)度、出勤情況好一般差工作進度快按計劃進行慢中期工作匯報及解答問題情況優(yōu)良中差中期成績評定：所在專業(yè)意見： 負責(zé)人： 年 月 日 河南機電高等?？茖W(xué)校畢業(yè)設(shè)計任務(wù)書系 部： 專 業(yè)： 學(xué)生姓名: 學(xué) 號: 設(shè)計題目: 空調(diào)墊片沖壓成形工藝及模具設(shè)計 起 迄 日 期: 2007 年 3 月20日6月18日 指 導(dǎo) 教 師: 發(fā)任務(wù)書日期: 2007 年 3 月 20 日畢 業(yè) 設(shè) 計 任 務(wù) 書1本畢業(yè)設(shè)計課題來源及應(yīng)達到的目的： 所示圖形為空調(diào)墊片零件，材料為10鋼，厚度2.1mm.設(shè)計一套沖壓模具，要求能適應(yīng)大批量生產(chǎn)。2本畢業(yè)設(shè)計課題任務(wù)的內(nèi)容和要求（包括原始數(shù)據(jù)、技術(shù)要求、工作要求等）： 1、了解目前國內(nèi)外沖壓模具的發(fā)展現(xiàn)狀2、分析空調(diào)墊片零件的沖壓成形工藝并確定其工藝方案3、空調(diào)墊片零件的沖壓模設(shè)計4、繪制模具總裝圖，并繪制零件圖5、空調(diào)墊片零件的模具安裝與調(diào)整6、得出設(shè)計結(jié)論所在專業(yè)審查意見：負責(zé)人： 年 月 日系部意見：系領(lǐng)導(dǎo)： 年 月 日河南機電高等專科學(xué)校畢業(yè)設(shè)計評語學(xué)生姓名：班級: 學(xué)號：題 目： 空調(diào)墊片沖壓成形工藝及模具設(shè)計 綜合成績： 指導(dǎo)者評語：周宇輝同學(xué)所做畢業(yè)設(shè)計的題目是空調(diào)墊片沖壓成形工藝及模具設(shè)計。該同學(xué)查閱了國內(nèi)有關(guān)沖壓模具設(shè)計與制造方面的大量資料，制定出了倒裝式復(fù)合模較合理的沖壓工藝。畢業(yè)設(shè)計中主要完成了該模具的結(jié)構(gòu)設(shè)計，及模具主要部件工藝規(guī)程的制定等工作。這些工作表明該同學(xué)已經(jīng)初步掌握了模具設(shè)計與制造方面的基本理論知識和技術(shù)技能，能夠基本解決生產(chǎn)一線中存在的一般性技術(shù)問題，具備了模具專業(yè)畢業(yè)生的畢業(yè)條件。該同學(xué)論文寫作比較認(rèn)真，條理比較清晰，計算合理，所畫圖紙結(jié)構(gòu)基本正確、可行，同意參加畢業(yè)答辯。建議成績良。 指導(dǎo)者(簽字)： 2007 年6月16 日畢業(yè)設(shè)計評語評閱者評語： 評閱者(簽字)： 年 月 日答辯委員會（小組）評語： 答辯委員會（小組）負責(zé)人(簽字)： 年 月 日河南機電高等?？茖W(xué)校 畢 業(yè) 設(shè) 計 說 明 書 畢業(yè)設(shè)計題目：空調(diào)墊片沖壓成形工藝及模具設(shè)計 系 部 材料工程系 專 業(yè) 模具設(shè)計與制造 班 級 模具 0 4 3 學(xué)生姓名 周 宇 輝 學(xué) 號 0412345 指導(dǎo)教師 原 紅 玲 2007 年 5 月 20 日 空調(diào)墊片倒裝式復(fù)合模設(shè)計 摘要 本模具為空調(diào)墊片沖孔落料復(fù)合模, 在設(shè)計時 :1 、接受任務(wù)書；2 、調(diào) 研消化原始資料；3 、選擇成形設(shè)備；4 、擬定模具結(jié)構(gòu)方案；5 、方案的討 論與論證；7 、繪制模具裝配圖；8 、繪制零件圖；9 、編寫設(shè)計說明書；10 、模具制造試模與圖紙修改。正確的確定模具成形零件的尺寸。沖孔凸模、落 料凹模、凸凹模等零件是確定制件形狀、尺寸和表面質(zhì)量的直接因素，關(guān)系甚 大，要特別注意。模具的設(shè)計應(yīng)制造方便, 盡量做道使設(shè)計的模具制造容易、 造價便宜。特別是比較復(fù)雜的成形零件，必須考慮是采用一般的機械加工方法 加工還是采用特殊的加工方法加工。模具的設(shè)計應(yīng)當(dāng)效率高、安全、可靠。模 具零件應(yīng)耐磨耐用。 關(guān)鍵詞：模具、成形、沖孔凸模、落料凹模、凸凹模。 Piercing and Blanking Characteristic of Compound Die of Conditioner Shim ABSTRACT This molding tool is a piercing and blanking characteristic of compound die of conditioner shim, while designing:1, accept the mission book.2 , the investigation digests the primitive data.3 , choose to the forming equipments.4 , draft the molding tool construction project.5 , the discussion of the project and argument.7 , drawing the molding tool assembles the diagram.8 , draw the spare parts diagram.9 , weave to write to design the manual.10 , the molding tool manufacturing tries the mold and diagram paper modification.The exactitude really settles size of the forming spare parts. piercing punch , blanking die, piercing punch & blanking die etc spare parts that molding tool forming spare parts is a direct factor that certain system a shape, size relate to with the surface quantity very big, want to be specially attention.The design of the molding tool should make the convenience, doing a molding tool manufacturing that make design easy and build the price cheapness to the best.Model the spare parts especially more complicatedly, must consider is to adopt the general machine process the method processes to adopt still to process specially the method processes.The design of the molding tool shoulds the efficiency high, safety, dependable.The molding tool spare parts should bear to whet enduring. Key Words: Molding tool, forming, piercing punch , blanking die ，piercing punch & blanking die . 插圖清單制件圖.4圖2-1 排樣圖.6壓力中心坐標(biāo)系圖.9圖4-1 圓形凸模.12圖4-2 凹模.13圖4-3 凸凹模.14空調(diào)墊片倒裝復(fù)合模裝配圖.15凸緣式模柄.18始用擋料銷.18表格清單彈簧數(shù)據(jù)表.16模具總體零件一覽表.18表7-1 凸模的工藝路線.21表7-2 凹模的工藝路線.22表7-3 凸凹模的工藝路線.23目 錄緒論.1國內(nèi)模具的現(xiàn)狀與發(fā)展趨勢.11.1 國內(nèi)模具的現(xiàn)狀.11.2 國內(nèi)模具發(fā)展趨勢.22. 國外模具的現(xiàn)狀與發(fā)展趨勢.3第一章 沖裁件的工藝分析及排樣.51.1沖裁件的工藝分析.51.2排樣.51.3工藝方案的確定.6第二章 模具結(jié)構(gòu)形式的選擇與確定.72.1 安裝結(jié)構(gòu).72.2 送料方式.72.3 定位裝置.72.4 導(dǎo)向方式.72.5 卸料方式.8第三章 沖壓力與壓力中心的計算.83.1 計算沖壓力.83.2 初選壓力機.83.3 確定壓力中心.9第四章 模具主要零件尺寸計算及機構(gòu)設(shè)計.104.1 計算凸、凹模刃口尺寸.104.2 凸模、凹模、凸凹模的結(jié)構(gòu)設(shè)計 .11第五章 模具總體設(shè)計及主要零部件設(shè)計.145.1 模具總體設(shè)計.145.2 卸料彈簧的設(shè)計計算.165.3 其他零部件設(shè)計.175.4 模具總體零件一覽表.18第六章 沖壓設(shè)備選擇.20第七章 模具主要成形零件加工工藝規(guī)程的編制.217.1 凸模的加工工藝規(guī)程.217.2凹模的加工工藝規(guī)程. .227.3凸凹模的加工工藝規(guī)程.23總結(jié).25結(jié)束語.26致謝.27參考文獻.28河南機電高等?？茖W(xué)校畢業(yè)設(shè)計說明書 緒 論 目前，我國沖壓技術(shù)與工業(yè)發(fā)達國家相比還相當(dāng)?shù)穆浜?，主要原因是我國在沖壓基礎(chǔ)理論及成形工藝、模具標(biāo)準(zhǔn)化、模具設(shè)計、模具制造工藝及設(shè)備等方面與工業(yè)發(fā)達的國家尚有相當(dāng)大的差距，導(dǎo)致我國模具在壽命、效率、加工精度、生產(chǎn)周期等方面與工業(yè)發(fā)達國家的模具相比差距相當(dāng)大。1 國內(nèi)模具的現(xiàn)狀和發(fā)展趨勢1.1 國內(nèi)模具的現(xiàn)狀我國模具近年來發(fā)展很快，據(jù)不完全統(tǒng)計，2003年我國模具生產(chǎn)廠點約有2萬多家，從業(yè)人員約50多萬人，2004年模具行業(yè)的發(fā)展保持良好勢頭，模具企業(yè)總體上訂單充足，任務(wù)飽滿，2004年模具產(chǎn)值530億元。進口模具18.13億美元，出口模具4.91億美元，分別比2003年增長18%、32.4%和45.9%。進出口之比2004年為3.69:1，進出口相抵后的進凈口達13.2億美元，為凈進口量較大的國家。在2萬多家生產(chǎn)廠點中，有一半以上是自產(chǎn)自用的。在模具企業(yè)中，產(chǎn)值過億元的模具企業(yè)只有20多家，中型企業(yè)幾十家，其余都是小型企業(yè)。近年來，模具行業(yè)結(jié)構(gòu)調(diào)整和體制改革步伐加快，主要表現(xiàn)為：大型、精密、復(fù)雜、長壽命中高檔模具及模具標(biāo)準(zhǔn)件發(fā)展速度快于一般模具產(chǎn)品；專業(yè)模具廠數(shù)量增加，能力提高較快；三資及私營企業(yè)發(fā)展迅速；國企股份制改造步伐加快等。雖然說我國模具業(yè)發(fā)展迅速，但遠遠不能適應(yīng)國民經(jīng)濟發(fā)展的需要。我國尚存在以下幾方面的不足: 第一，體制不順，基礎(chǔ)薄弱。 “三資”企業(yè)雖然已經(jīng)對中國模具工業(yè)的發(fā)展起了積極的推動作用，私營企業(yè)近年來發(fā)展較快，國企改革也在進行之中，但總體來看，體制和機制尚不適應(yīng)市場經(jīng)濟，再加上國內(nèi)模具工業(yè)基礎(chǔ)薄弱，因此，行業(yè)發(fā)展還不盡如人意，特別是總體水平和高新技術(shù)方面。 第二，開發(fā)能力較差，經(jīng)濟效益欠佳.我國模具企業(yè)技術(shù)人員比例低，水平較低，且不重視產(chǎn)品開發(fā)，在市場中經(jīng)常處于被動地位。我國每個模具職工平均年創(chuàng)造產(chǎn)值約合1萬美元，國外模具工業(yè)發(fā)達國家大多是1520萬美元，有的高達2530萬美元，與之相對的是我國相當(dāng)一部分模具企業(yè)還沿用過去作坊式管理，真正實現(xiàn)現(xiàn)代化企業(yè)管理的企業(yè)較少。 第三，工藝裝備水平低，且配套性不好，利用率低雖然國內(nèi)許多企業(yè)采用了先進的加工設(shè)備，但總的來看裝備水平仍比國外企業(yè)落后許多，特別是設(shè)備數(shù)控化率和CAD/CAM應(yīng)用覆蓋率要比國外企業(yè)低得多。由于體制和資金等原因，引進設(shè)備不配套，設(shè)備與附配件不配套現(xiàn)象十分普遍，設(shè)備利用率低的問題長期得不到較好解決。裝備水平低，帶來中國模具企業(yè)鉗工比例過高等問題。 第四，專業(yè)化、標(biāo)準(zhǔn)化、商品化的程度低、協(xié)作差 由于長期以來受“大而全”“小而全”影響，許多模具企業(yè)觀念落后，模具企業(yè)專業(yè)化生產(chǎn)水平低，專業(yè)化分工不細，商品化程度也低。目前國內(nèi)每年生產(chǎn)的模具，商品模具只占45%左右，其馀為自產(chǎn)自用。模具企業(yè)之間協(xié)作不好，難以完成較大規(guī)模的模具成套任務(wù)，與國際水平相比要落后許多。模具標(biāo)準(zhǔn)化水平低，標(biāo)準(zhǔn)件使用覆蓋率低也對模具質(zhì)量、成本有較大影響，對模具制造周期影響尤甚。 第五，模具材料及模具相關(guān)技術(shù)落后模具材料性能、質(zhì)量和品種往往會影響模具質(zhì)量、壽命及成本，國產(chǎn)模具鋼與國外進口鋼相比，無論是質(zhì)量還是品種規(guī)格，都有較大差距。塑料、板材、設(shè)備等性能差，也直接影響模具水平的提高。1.2國內(nèi)模具的發(fā)展趨勢 巨大的市場需求將推動中國模具的工業(yè)調(diào)整發(fā)展。雖然我國的模具工業(yè)和技術(shù)在過去的十多年得到了快速發(fā)展，但與國外工業(yè)發(fā)達國家相比仍存在較大差距，尚不能完全滿足國民經(jīng)濟高速發(fā)展的需求。未來的十年，中國模具工業(yè)和技術(shù)的主要發(fā)展方向包括以下幾方面: 1） 模具日趨大型化； 2）在模具設(shè)計制造中廣泛應(yīng)用CAD/CAE/CAM技術(shù)； 3）模具掃描及數(shù)字化系統(tǒng)； 4）在塑料模具中推廣應(yīng)用熱流道技術(shù)、氣輔注射成型和高壓注射成型技術(shù)； 5）提高模具標(biāo)準(zhǔn)化水平和模具標(biāo)準(zhǔn)件的使用率；6）發(fā)展優(yōu)質(zhì)模具材料和先進的表面處理技術(shù)；7）模具的精度將越來越高； 8）模具研磨拋光將自動化、智能化； 9）研究和應(yīng)用模具的高速測量技術(shù)與逆向工程；10）開發(fā)新的成形工藝和模具。2國外模具的現(xiàn)狀和發(fā)展趨勢模具是工業(yè)生產(chǎn)關(guān)鍵的工藝裝備，在電子、建材、汽車、電機、電器、儀器儀表、家電和通訊器材等產(chǎn)品中，6080的零部件都要依靠模具成型。用模具生產(chǎn)制作表現(xiàn)出的高效率、低成本、高精度、高一致性和清潔環(huán)保的特性，是其他加工制造方法所無法替代的。模具生產(chǎn)技術(shù)水平的高低，已成為衡量一個國家制造業(yè)水平高低的重要標(biāo)志，并在很大程度上決定著產(chǎn)品的質(zhì)量、效益和新產(chǎn)品的開發(fā)能力。近幾年，全球模具市場呈現(xiàn)供不應(yīng)求的局面，世界模具市場年交易總額為600650億美元左右。美國、日本、法國、瑞士等國家年出口模具量約占本國模具年總產(chǎn)值的三分之一。國外模具總量中,大型、精密、復(fù)雜、長壽命模具的比例占到50%以上；國外模具企業(yè)的組織形式是大而專、大而精。2004年中國模協(xié)在德國訪問時，從德國工、模具行業(yè)組織-德國機械制造商聯(lián)合會（VDMA）工模具協(xié)會了解到，德國有模具企業(yè)約5000家。2003年德國模具產(chǎn)值達48億歐元。其中（VDMA）會員模具企業(yè)有90家，這90家骨干模具企業(yè)的產(chǎn)值就占德國模具產(chǎn)值的90%，可見其規(guī)模效益。 隨著時代的進步和技術(shù)的發(fā)展，國外的一些掌握和能運用新技術(shù)的人才如模具結(jié)構(gòu)設(shè)計、模具工藝設(shè)計、高級鉗工及企業(yè)管理人才，他們的技術(shù)水平比較高故人均產(chǎn)值也較高我國每個職工平均每年創(chuàng)造模具產(chǎn)值約合1萬美元左右，而國外模具工業(yè)發(fā)達國家大多1520萬美元，有的達到 2530萬美元。國外先進國家模具標(biāo)準(zhǔn)件使用覆蓋率達70%以上，而我國才達到45空調(diào)墊片倒裝式復(fù)合沖裁模設(shè)計 原始資料： 如圖所示 材 料： 10鋼厚 度： 2.1mm 生產(chǎn)批量： 大批量 制件圖第一章 沖裁件工藝分析及排樣1.1沖裁件工藝分析圖示零件材料為10鋼板，能夠進行一般的沖壓加工，市場上也容易得到這種材料，價格適中。 該零件形狀簡單、結(jié)構(gòu)對稱，是由圓和直線組成的。由沖壓設(shè)計資料中可查出，沖裁件內(nèi)外形所能達到的經(jīng)濟精度為IT12IT13，孔中心與邊緣距離尺寸公差為。將以上精度與零件簡圖中所標(biāo)注的尺寸公差相比較，可知該零件的精度要求能夠在沖裁加工中得到保證。其他尺寸標(biāo)注、生產(chǎn)批量等情況，也均符合沖裁的工藝要求。由以上分析可知，圖示零件具有比較好的沖壓工藝性，適合沖壓生產(chǎn)。1.2排樣設(shè)計模具時，條料的排樣很重要。根據(jù)墊片零件的特點，可采用直對排的排樣方案可以提高材料的利用率，減少廢料，保證零件尺寸，如圖2-1所示。由設(shè)計手冊查得最小搭邊值a=3mm。計算沖壓件毛坯面積 條料寬度：進距： 一個進距的材料利用率為 圖2-1 排樣圖1.3工藝方案的確定墊片零件所需的基本沖壓工序為落料和沖孔，可擬訂出以下三種工藝方案。方案一：用簡單模分兩次加工，即落料沖孔，單工序模生產(chǎn).方案二：沖孔落料復(fù)合沖壓。采用沖孔落料復(fù)合模進行加工，且一次沖壓成形。方案三：沖孔落料級進沖壓。采用級進模進行加工。 采用方案一，生產(chǎn)率低，難以滿足大，中批量生產(chǎn)要求。工件的累計誤差大，操作不方便，由于該工件為大，中批量生產(chǎn)，方案二和方案三更具有優(yōu)越性。墊片零件上26孔與壁之間的距離符合采用沖孔、落料復(fù)合?；驔_孔、落料連續(xù)模。連續(xù)模主要生產(chǎn)尺寸較大的工件，模具也較大。復(fù)合模模具制造難度雖然大，但其孔與孔之間的定位準(zhǔn)確，容易保證位置精度。因此選用復(fù)合模更為合理。故決定采用沖孔落料復(fù)合沖裁模進行加工，且一次沖壓成形。第二章 模具結(jié)構(gòu)形式的選擇與確定2.1安裝結(jié)構(gòu)根據(jù)上述分析，本零件的沖壓包括沖孔和落料兩個工序，為方便小孔廢料和成形工件的落下，采用倒裝結(jié)構(gòu)，即落料凹模和沖孔凸模都安排在上模座，凸凹模安排在下模座。2.2送料方式因條料寬度不大，大、中批量生產(chǎn)，考慮到送料方便，且提高生產(chǎn)效率，可采用從右向左手動送料方式，考慮到制件的排樣和模具的結(jié)構(gòu)形式，條料還需調(diào)頭再次沖裁。2.3定位裝置本工件在復(fù)合模中尺寸是較小的，但是大批量生產(chǎn)，沖裁時工位前端先采用固定擋料銷定位，第二工位靠固定擋料銷擋住已沖材料的后端。送料時固定擋料銷控制其送料步距。旁邊有兩個導(dǎo)料銷進行導(dǎo)向，保證條料沿給定方向運動。2.4導(dǎo)向方式為確保零件的質(zhì)量及穩(wěn)定性，選用導(dǎo)柱、導(dǎo)套導(dǎo)向?？紤]到送料方便，模具采用后側(cè)導(dǎo)柱模架。2.5卸料方式本模具采用倒裝結(jié)構(gòu)，卸料采用彈性卸料裝置，彈性卸料裝置由卸料板、卸料螺釘和彈簧組成。沖制的工件由推桿、推板、推銷和推件塊組成的剛性推件裝置推出。沖孔的廢料可通過凸凹模的內(nèi)孔從沖床臺面孔漏下。第三章 沖壓力與壓力中心的計算3.1 計算沖壓力 該模具草用彈性卸料和下出料方式。落料力 沖孔力 落料時的卸料力 查設(shè)計手冊得：取，故 沖孔時的推件力 根據(jù)手冊凹模刃口形式選擇，取h=5mm,則n=h/t=5/2.22(個)。查表得，故 選擇沖床時的總沖壓力為 3.2 初選壓力機初選開式雙柱可傾壓力機J2340。 公稱壓力：400kN；滑塊行程：100mm；最大閉合高度：330；封閉高度調(diào)節(jié)量：65；工作臺尺寸（前后左右）：；尺寸（厚度孔徑）：65220；孔尺寸（直徑深度）：5070；傾斜角度：3.3 確定模具壓力中心按比例畫出零件形狀，選定坐標(biāo)系xOy，如下圖所示。 零件左右對稱，即，故只需計算。將工件沖裁周邊分成基本線段，求出各段長度及各段的重心位置：=45mm , =0=88mm , =22mm=25mm , =44mm=132mm , =77mm=31.4mm, =110+6.29=116.29mm=81.64mm, =22mm第四章 模具主要零件尺寸計算及機構(gòu)設(shè)計4.1 計算凸、凹模刃口尺寸查表得間隙值。對沖孔 26mm采用凸、凹模分開的加工方法，其凸、凹模刃口部分尺寸計算如下：查表得凸、凹模制造公差： 效核： 滿足的條件。查表得因數(shù)，按式()得： 對外輪廓的落料，由于形狀較復(fù)雜，故采用配合加工方法，其凸凹模刃口部分尺寸算如下：當(dāng)以凹模為基準(zhǔn)件時，凹模磨損后，刃口部分尺寸都增大，因此均屬于A類尺寸。零件圖中未標(biāo)公差的尺寸，由沖壓設(shè)計資料中查出其極限偏差：查表得因數(shù)為：當(dāng)時，=0.5；當(dāng)0.50時，=0.75，按式()得 凹模刃口尺寸(mm)零件的公差(mm) 4.2 凸模、凹模、凸凹模的結(jié)構(gòu)設(shè)計沖26mm孔的圓形凸模，由于模具需要在凸模外面裝推件塊，因此設(shè)計成直拄的形狀。尺寸標(biāo)注如圖4-1所示。凹模的刃口形式，考慮到本例生產(chǎn)批量較大，所以采用刃口強度較高的凹模，即圖4-2所示的刃口形式。凹模的外形尺寸，按式()和式()計算得：H=Kb=0.24120=29mm,C=1.5H=43mm。尺寸標(biāo)注如圖5-2所示。H凹模厚度(mm)C凹模壁厚(mm)K系數(shù)b沖裁件最大外形尺寸(mm) 圖4-1 圓形凸模 圖4-2 凹模 圖4-3 凸凹模本模具為復(fù)合沖裁模，因此除沖孔凸模和落料凹模外，必然還有一個凸凹模。凸凹模的結(jié)構(gòu)簡圖如圖4-3所示。校核凸凹模的強度：按凸凹模的最小壁厚m=1.5t=3.3mm,而實際最小壁厚為9mm，故符合強度要求。凸凹模的外刃口尺寸按凹模尺寸配制并保證雙面間隙0.260.38。凸凹模上孔中心與邊緣距離尺寸22mm的公差，應(yīng)比零件圖所標(biāo)精度高34級，即定為220.15mm。第五章 模具總體設(shè)計及主要零部件設(shè)計5.1 模具總體設(shè)計下圖所示為本例的模具總圖。該復(fù)合沖裁模將凹模及小凸模裝在上模上，是典型的倒裝結(jié)構(gòu)。1上模座；2螺釘；3推桿；4模柄；5推板；6推銷；7螺栓；8銷釘；9墊板；10凸模固定板；11推件塊；12導(dǎo)套；13凹模；14卸料板；15導(dǎo)柱；16凸凹模；17彈簧；18下模座；19螺釘；20銷釘；21卸料螺釘；22擋料銷；23凸模；24始用擋料銷；25螺釘；26導(dǎo)料銷；27小擋板；28墊圈空調(diào)墊片倒裝復(fù)合模本模具是一副沖孔落料倒裝復(fù)合模，采用了后側(cè)導(dǎo)柱模架，排樣為直對排，用調(diào)頭沖送料的方式。調(diào)頭沖首件時，應(yīng)先用手旋轉(zhuǎn)始用擋料銷24，使銷頭抬起，起臨時擋料作用，沖裁后松開始用擋料銷24使之復(fù)位，以后可用固定擋料銷。兩個導(dǎo)料銷控制條料送進的導(dǎo)向，固定擋料銷控制送料的進距。卸料采用彈性卸料裝置，彈性卸料裝置由卸料板、卸料螺釘和彈簧組成。沖制的工件由推桿、推板、推銷和推件塊組成的剛性推件裝置推出。沖孔的廢料可通過凸凹模的內(nèi)孔從沖床臺面孔漏下。5.2 卸料彈簧的設(shè)計計算根據(jù)模具結(jié)構(gòu)初定6根彈簧，每根彈簧分擔(dān)的卸料力為：。根據(jù)預(yù)壓力和模具結(jié)構(gòu)尺寸，由沖壓設(shè)計資料中選出序號6872的彈簧，其最大工作負荷效驗是否滿足。查沖壓設(shè)計資料及負荷一行程曲線，經(jīng)計算可得一下數(shù)據(jù)： 由下表數(shù)據(jù)可見，序號7072的彈簧均滿足，但選序號70的彈簧最合適，因為其他彈簧太長，會使模具高度增加。 彈簧數(shù)據(jù)表序號686044.515.5 10.518.76980 58.2 21.8 15 23.270 120 85.7 34.3 23 31.271160113.2 46.8 30 38.272 200 140.5 59.5 40 48.270號彈簧的規(guī)格為：外徑：D=45mm，鋼絲直徑：d=7.0mm，自由高度：=120mm裝配高度：5.3 其他零部件設(shè)計模架選用中等精度，中、小尺寸沖壓件的后側(cè)導(dǎo)柱模架，從右向左送料，操作方便。模架的凹模周界?。篖=250mm,B=250mm.上模座： 下模座： 導(dǎo) 柱： 導(dǎo) 套： 墊板厚度取：12 上模板厚度：50凸模固定板厚度?。?0凹模的厚度定為：29下模板厚度：65卸料板厚度?。?4彈簧的外露高度：安裝彈簧上、下沉孔深度分別為：6、35；模柄選用凸緣式，標(biāo)記為：C50391 JB/T 7646.3模具的閉合高度： 模柄與上模座的聯(lián)接的結(jié)構(gòu)如圖所示： 凸緣式模柄始用擋料銷的結(jié)構(gòu)如圖所示：5.4模具總體零件一覽表模具總體零件一覽表序號名稱件數(shù)材料備注1上模座1HT2002503250350 GB/T2855.52內(nèi)六角螺釘335鋼M10335 GB70853推桿145鋼4模柄1Q235C50391 JB/T 7646.35推板145鋼6推銷645鋼7螺栓635鋼M12390 GB 119868圓柱銷235鋼103100 GB 119869墊板145鋼10凸模固定板145鋼11推件塊145鋼12導(dǎo)套220ISO 9448-2 A35312534813凹模1T8A14卸料板145鋼15導(dǎo)柱220ISO 9182-2 A35320016凸凹模1T8A17彈簧645鋼70號18下模座1HT2002503250365 GB/T2855.619螺釘735鋼M10385 GB708520圓柱銷235鋼103100 GB 1198621卸料螺釘635鋼M123110 JB/T 7650.622擋料銷145鋼8mm，h=48mm, JB/T7649.109423凸模1T8A24始用擋料銷145鋼25螺釘135鋼26導(dǎo)料銷245鋼27小擋板145鋼28墊圈145鋼第六章 沖壓設(shè)備的選擇根據(jù)以上計算，選用開式雙柱可傾壓力機J2340。公稱壓力：400kN；滑塊行程：100mm；最大閉合高度：330；閉和高度調(diào)節(jié)量：65；工作臺尺寸（前后左右）：；尺寸（厚度孔徑）：65220；孔尺寸（直徑深度）：5070；傾斜角度：第七章 模具主要成形零件加工工藝規(guī)程的編制7.1 凸模的加工工藝規(guī)程由于凸模結(jié)構(gòu)簡單，制造方便，可采用一般機械加工。 表7-1 凸模的工藝路線工序號工序名稱工序內(nèi)容設(shè)備1下料按尺寸40mm355mm鋸下棒料鋸床2熱處理退火3粗加工毛坯銑(刨)兩端面，磨圓柱面，保證尺寸銑(刨)床、磨床4磨端面磨兩端面，保證尺寸與平行度磨床5磨圓柱面磨圓柱面，尺寸至凸模大圓尺寸磨床6鉗工劃線劃刃口輪廓線及臺階線7臺階磨削按線磨削，留單面余量0.6mm坐標(biāo)磨床8車退刀槽按劃線車退刀槽車床9磨型面按線磨刃口型面，留單面余量0.3mm外圓坐標(biāo)磨床10鉗工修正保證表面平整，余量均勻11熱處理淬火回火，保證5862HRC12磨端面磨兩端面，保證與型面垂直磨床13精磨型面磨刃口型面達設(shè)計要求外圓坐標(biāo)磨床7.2 凹模的加工工藝規(guī)程表7-2 凹模的工藝路線工序號工序名稱工序內(nèi)容設(shè)備1下料將毛坯鍛成平行六面體。尺寸為：210mm135mm35mm鍛床2熱處理退火3銑(刨)平面銑(刨)各平面，厚度留磨削余量0.6mm，側(cè)面留磨削余量0.4mm銑(刨) 床4磨平面磨上下平面，留磨削余量0.30.4mm；磨相臨兩側(cè)面，保證垂直磨床5鉗工劃線劃出對稱中心線，固定孔及銷孔線6型孔粗加工在仿銑床上加工型孔，留單邊加工余量0.15mm 仿銑床7階梯孔加工按圖樣磨階梯孔，達尺寸要求坐標(biāo)磨床8加工余孔加工固定孔及銷孔鉆床9熱處理淬火回火，保證5862HRC10磨平面磨上下面及基準(zhǔn)面達要求磨床11型孔精加工在坐標(biāo)磨床上磨型孔，留研磨余量0.01mm坐標(biāo)磨床12研磨型孔鉗工研磨型孔達規(guī)定技術(shù)要求7.3 凸凹模的加工工藝規(guī)程表7-3 凸凹模的工藝路線工序號工序名稱工序內(nèi)容設(shè)備1下料將毛坯鍛成平行六面體。尺寸為：185mm100mm75mm鍛床2熱處理退火3銑(刨)平面銑(刨)各平面，厚度留磨削余量0.6mm，側(cè)面留磨削余量0.4mm銑(刨) 床4磨平面磨上下平面，留磨削余量0.30.4mm；磨相臨兩側(cè)面，保證垂直磨床5鉗工劃線劃出零件及刃口輪廓線，固定孔及銷孔線6外形輪廓加工按劃線加工外形輪廓面，達尺寸要求坐標(biāo)磨床7型面加工按劃線加工型面，留單邊加工余量0.15mm坐標(biāo)磨床8型孔加工按劃線加工型孔，留單邊加工余量0.15mm坐標(biāo)磨床9階梯孔加工按圖樣磨階梯孔，達尺寸要求坐標(biāo)磨床10加工余孔加工固定孔及銷孔鉆床11熱處理淬火回火，保證5862HRC12磨平面磨上下面及基準(zhǔn)面達要求磨床13型面精加工在坐標(biāo)磨床上磨型面，留研磨余量0.01mm坐標(biāo)磨床14型孔精加工在坐標(biāo)磨床上磨型孔，留研磨余量0.01mm坐標(biāo)磨床15研磨型孔、型面鉗工研磨型孔、型面達規(guī)定技術(shù)要求總 結(jié) 通過這次課程設(shè)計使我學(xué)到了許多知識，對一些原來一知半解的理論也有了清楚的認(rèn)識。特別是原來所學(xué)的一些專業(yè)基礎(chǔ)課：如機械制圖、模具材料、公差配合與技術(shù)測量、塑料模具設(shè)計與制造等有了更深刻的理解，使制造的模具既能滿足使用要求有不浪費材料，保證了工件的經(jīng)濟性，設(shè)計的合理性。通過沖壓模手冊、模具制造簡明手冊、模具標(biāo)準(zhǔn)應(yīng)用手冊等了解到許多原來未知的知識。 由于能力有限，設(shè)計中難免有疏漏之處，懇請老師給予指正。我在此衷心謝謝原老師的大力幫助與指導(dǎo)。結(jié) 束 語空調(diào)墊片制件屬于簡單沖裁件，首先分析其工藝性，并確定工藝方案。根據(jù)計算確定本制件所需的沖壓力及其壓力中心，然后選取相應(yīng)的壓力機。本設(shè)計主要是模具成形零件的設(shè)計，包括凸模、凹模、凸凹模。需要計算凸、凹模尺寸和公差，及凸、凹模刃口之間間隙的確定。并且還需要確定模具的總體尺寸和模具零件的結(jié)構(gòu)，然后根據(jù)上面的設(shè)計繪出模具的總裝圖。 由于在零件制造前進行了預(yù)測，分析了制件在生產(chǎn)過程中可能出現(xiàn)的缺陷，采取了相應(yīng)的工藝措施。因此，模具在生產(chǎn)零件的時候才可以減少廢品的產(chǎn)生。 空調(diào)墊片制件的形狀結(jié)構(gòu)較為簡單，制造方便，可選用標(biāo)準(zhǔn)模架。為保證零件的順利加工和取件，選用后側(cè)導(dǎo)柱模架，并使凸模與凹模安裝在上模座，凸凹模安裝在下模座，設(shè)計為典型的倒裝復(fù)合模。模具工作零件的結(jié)構(gòu)也較為簡單，可以相應(yīng)的簡化模具結(jié)構(gòu)。便以以后的操作、調(diào)整和維護?？照{(diào)墊片倒裝復(fù)合模具的設(shè)計，是理論知識與實踐有機的結(jié)合，更加系統(tǒng)地對理論知識做了更深切貼實的闡述。也使我認(rèn)識到，要想做為一名合格的模具設(shè)計人員，必須要有扎實的專業(yè)基礎(chǔ)，并不斷學(xué)習(xí)新知識新技術(shù)，樹立終身學(xué)習(xí)的觀念，把理論知識應(yīng)用到實踐中去，并堅持科學(xué)、嚴(yán)謹(jǐn)、求實的精神，大膽創(chuàng)新，突破新技術(shù)，為國民經(jīng)濟的騰飛做出應(yīng)有的貢獻。致 謝匆忙之中就馬上就要結(jié)束大學(xué)生活了，作為一名合格的大學(xué)生,畢業(yè)設(shè)計是我們每個人都必須認(rèn)真完成的任務(wù)，也是對大學(xué)里面所學(xué)所有課程的一次綜合的回顧，也是考驗我們在這里學(xué)到所有知識的掌握程度。本次畢業(yè)設(shè)計對我們來說時間真的有點倉促，因為平時的知識掌握不牢固，很多東西都要在圖書館里面慢慢摸索。不過值得慶幸的是在這個過程中有原紅玲老師的耐心指導(dǎo)，每周不顧舟車勞頓辛苦的原老師都會準(zhǔn)時為我們的疑問做一個認(rèn)真的答復(fù)，雖然我們的基礎(chǔ)不是很好，老師卻從沒有放棄我們，總是耐心的鼓勵和悉心的指導(dǎo)。原老師對我們的嚴(yán)格要求也給我們一定的壓力，這就讓我們不能自我放縱懈怠，也只有這樣才能靜下心來做未完成的任務(wù)，雖然我感覺我們做的還不夠好，還有很多東西我們都不是很清楚明了，但是讓我明白了作為一名模具專業(yè)的畢業(yè)生孜孜以求，學(xué)術(shù)專攻，這些是我們每個人都必須具備的基本素質(zhì)。原老師以其嚴(yán)謹(jǐn)求實的治學(xué)態(tài)度、高度的敬業(yè)精神、兢兢業(yè)業(yè)、和大膽創(chuàng)新的進取精神對我產(chǎn)生重要影響。原老師淵博的知識、開闊的視野和敏銳的思維給了我深深的啟迪。同時，在此次畢業(yè)設(shè)計過程中我也學(xué)到了許多了關(guān)于沖壓模具設(shè)計方面的知識，實際動手設(shè)計和操作技能有了很大的提高。 另外，我還要特別感謝本專業(yè)的程芳老師,翟德梅老師,楊占堯老師和于智宏等老師對我的實驗以及論文寫作的指導(dǎo)，他們對我完成這篇論文提供了大力的幫助和支持。 最后，再次對關(guān)心、幫助我的老師和同學(xué)表示衷心地感謝！參考文獻1吳伯杰編.沖壓工藝與模具.北京：電子工業(yè)出版社，20052陳錫棟、周小玉主編.實用模具技術(shù)手冊M.北京：機械工業(yè)出版社，20013李紹林、馬長福主編.實用模具技術(shù)手冊M.上海科學(xué)技術(shù)出版社，19984許發(fā)樾主編.實用模具設(shè)計與制造手冊M.北京：機械工業(yè)出版社，20005楊玉英主編.實用沖壓工藝及模具設(shè)計手冊M. 北京：機械工業(yè)出版社，20046模具實用技術(shù)叢書編委會.沖壓設(shè)計應(yīng)用實例M.北京：機械工業(yè)出版社.19997翟德梅主編.模具制造技術(shù)M.河南機電高等?？茖W(xué)校8王芳主編.冷沖壓模具設(shè)計指導(dǎo)M. 北京：機械工業(yè)出版社，19989任嘉卉主編.公差與配合手冊M. 北京：機械工業(yè)出版社，200010李易、于成功、聞小芝主編.現(xiàn)代模具設(shè)計、制造、調(diào)試與維修實用手冊M.北京：金版電子出版公司，200311彭建聲、秦曉剛編著.模具技術(shù)問答M. 北京：機械工業(yè)出版社，199628INEEL/CON-2000-00104 PREPRINT Spray-Formed Tooling for Injection Molding and Die Casting Applications K. M. McHugh B. R. Wickham June 26, 2000 June 28, 2000 International Conference on Spray Deposition and Melt Atomization This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint should not be cited or reproduced without permission of the author. This document was prepared as a account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third partys use, or the results of such use, of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights. The views expressed in this paper are not necessarily those of the U.S. Government or the sponsoring agency. BECHTEL BWXT IDAHO, LLC 1 Spray-Formed Tooling For Injection Molding and Die Casting Applications Kevin M. McHugh and Bruce R. Wickham Idaho National Engineering and Environmental Laboratory P.O. Box 1625 Idaho Falls, ID 83415-2050 e-mail: kmm4inel.gov Abstract Rapid Solidification Process (RSP) Tooling is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described. Introduction Molds, dies, and related tooling are used to shape many of the plastic and metal components we use every day at home or at work. The process involves machining the negative of a desired part shape (core and cavity) from a forged tool steel or a rough metal casting, adding cooling channels, vents, and other mechanical features, followed by grinding. Many molds and dies undergo heat treatment (austenitization/quench/temper) to improve the properties of the steel, followed by final grinding and polishing to achieve the desired finish 1. Conventional fabrication of molds and dies is very expensive and time consuming because: Each is custom made, reflecting the shape and texture of the desired part. The materials used to make tooling are difficult to machine and work with. Tool steels are the workhorse of industry for long production runs. Machining tool steels is capital equipment intensive because specialized equipment is often needed for individual machining steps. Tooling must be machined accurately. Oftentimes many individual components must fit together correctly for the final product to function properly. 2 Costs for plastic injection molds vary with size and complexity, ranging from about $10,000 to over $300,000 (U.S.), and have lead times of 3 to 6 months. Tool checking and part qualification may require an additional 3 months. Large die-casting dies for transmissions and sheet metal stamping dies for making automobile body panels may cost more than $1million (U.S.). Lead times are usually greater than 40 weeks. A large automobile company invests about $1 billion (U.S.) in new tooling each year to manufacture the components that go into their new line of cars and trucks. Spray forming offers great potential for reducing the cost and lead time for tooling by eliminating many of the machining, grinding, and polishing unit operations. In addition, spray forming provides a powerful means to control segregation of alloying elements during solidification and carbide formation, and the ability to create beneficial metastable phases in many popular ferritic tool steels. As a result, relatively low temperature precipitation hardening heat treatment can be used to tailor properties such as hardness, toughness, thermal fatigue resistance, and strength. This paper describes the application of spray forming technology for producing H13 tooling for injection molding and die casting applications, and the benefits of low temperature heat treatment. RSP Tooling Rapid Solidification Process (RSP) Tooling, is a spray forming technology tailored for producing molds and dies 2-4. The approach combines rapid solidification processing and net- shape materials processing in a single step. The general concept involves converting a mold design described by a CAD file to a tooling master using a suitable rapid prototyping (RP) technology such as stereolithography. A pattern transfer is made to a castable ceramic, typically alumina or fused silica (Figure 1). This is followed by spray forming a thick deposit of tool steel (or other alloy) on the pattern to capture the desired shape, surface texture and detail. The resultant metal block is cooled to room temperature and separated from the pattern. Typically, the deposits exterior walls are machined square, allowing it to be used as an insert in a holding block such as a MUD frame 5. The overall turnaround time for tooling is about three days, stating with a master. Molds and dies produced in this way have been used for prototype and production runs in plastic injection molding and die casting. Figure 1. RSP Tooling processing steps. 3 An important benefit of RSP Tooling is that it allows molds and dies to be made early in the design cycle for a component. True prototype parts can be manufactured to assess form, fit, and function using the same process planned for production. If the part is qualified, the tooling can be run in production as conventional tooling would. Use of a digital database and RP technology allows design modifications to be easily made. Experimental Procedure An alumina-base ceramic (Cotronics 780 6) was slurry cast using a silicone rubber master die, or freeze cast using a stereolithography master. After setting up, ceramic patterns were demolded, fired in a kiln, and cooled to room temperature. H13 tool steel was induction melted under a nitrogen atmosphere, superheated about 100C, and pressure-fed into a bench-scale converging/diverging spray nozzle, designed and constructed in-house. An inert gas atmosphere within the spray apparatus minimized in-flight oxidation of the atomized droplets as they deposited onto the tool pattern at a rate of about 200 kg/h. Gas-to-metal mass flow ratio was approximately 0.5. For tensile property and hardness evaluation, the spray-formed material was sectioned using a wire EDM and surface ground to remove a 0.05 mm thick heat-affected zone. Samples were heat treated in a furnace that was purged with nitrogen. Each sample was coated with BN and placed in a sealed metal foil packet as a precautionary measure to prevent decarburization. Artificially aged samples were soaked for 1 hour at temperatures ranging from 400 to 700C, and air cooled. Conventionally heat treated H13 was austenitized at 1010C for 30 min., air quenched, and double tempered (2 hr plus 2 hr) at 538C. Microhardness was measured at room temperature using a Shimadzu Type M Vickers Hardness Tester by averaging ten microindentation readings. Microstructure of the etched (3% nital) tool steel was evaluated optically using an Olympus Model PME-3 metallograph and an Amray Model 1830 scanning electron microscope. Phase composition was analyzed via energy- dispersive spectroscopy (EDS). The size distribution of overspray powder was analyzed using a Microtrac Full Range Particle Analyzer after powder samples were sieved at 200 m to remove coarse flakes. Sample density was evaluated by water displacement using Archimedes principle and a Mettler balance (Model AE100). A quasi 1-D computer code developed at INEEL was used to evaluate multiphase flow behavior inside the nozzle and free jet regions. The codes basic numerical technique solves the steady- state gas flow field through an adaptive grid, conservative variables approach and treats the droplet phase in a Lagrangian manner with full aerodynamic and energetic coupling between the droplets and transport gas. The liquid metal injection system is coupled to the throat gas dynamics, and effects of heat transfer and wall friction are included. The code also includes a nonequilibrium solidification model that permits droplet undercooling and recalescence. The code was used to map out the temperature and velocity profile of the gas and atomized droplets within the nozzle and free jet regions. 4 Results and Discussion Spray forming is a robust rapid tooling technology that allows tool steel molds and dies to be produced in a straightforward manner. Examples of die inserts are given in Figure 2. Each was spray formed using a ceramic pattern generated from a RP master. Figure 2. Spray-formed mold inserts. (a) Ceramic pattern and H13 tool steel insert. (b) P20 tool steel insert. Particle and Gas Behavior Particle mass frequency and cumulative mass distribution plots for H13 tool steel sprays are given in Figure 3. The mass median diameter was determined to be 56 m by interpolation of size corresponding to 50% cumulative mass. The area mean diameter and volume mean diameter were calculated to be 53 m and 139 m, respectively. Geometric standard deviation, d =(d 84 /d 16 ) , is 1.8, where d 84 and d 16 are particle diameters corresponding to 84% and 16% cumulative mass in Figure 3. 5 Figure 3. Cumulative mass and mass frequency plots of particles in H13 tool step sprays. Figure 4 gives computational results for the multiphase velocity flow field (Figure 4a), and H13 tool steel solid fraction (Figure 4b), inside the nozzle and free jet regions. Gas velocity increases until reaching the location of the shock front, at which point it precipitously decreases, eventually decaying exponentially outside the nozzle. Small droplets are easily perturbed by the velocity field, accelerating inside the nozzle and decelerating outside. After reaching their terminal velocity, larger droplets (150 m) are less perturbed by the flow field due to their greater momentum. It is well known that high particle cooling rates in the spray jet (10 3 -10 6 K/s) and bulk deposit (1- 100 K/min) are present during spray forming 7. Most of the particles in the spray have undergone recalescence, resulting in a solid fraction of about 0.75. Calculated solid fraction profiles of small (30 m) and large (150 m) droplets with distance from the nozzle inlet, are shown in Figure 4b. Spray-Formed Deposits This high heat extraction rate reduces erosion effects at the surface of the tool pattern. This allows relatively soft, castable ceramic pattern materials to be used that would not be satisfactory candidates for conventional metal casting processes. With suitable processing conditions, fine 6 Figure 4. Calculated particle and gas behavior in nozzle and free jet regions. (a) Velocity profile. (b) Solid fraction. 7 surface detail can be successfully transferred from the pattern to spray-formed mold. Surface roughness at the molding surface is pattern dependent. Slurry-cast commercial ceramics yield a surface roughness of about 1 m Ra, suitable for many molding applications. Deposition of tool steel onto glass plates has yielded a specular surface finish of about 0.076 m Ra. At the current state of development, dimensional repeatability of spray-formed molds, starting with a common master, is about 0.2%. Chemistry The chemistry of H13 tool steel is designed to allow the material to withstand the temperature, pressure, abrasion, and thermal cycling associated with demanding applications such as die casting. It is the most popular die casting alloy worldwide and second most popular tool steel for plastic injection molding. The steel has low carbon content (0.4 wt.%) to promote toughness, medium chromium content (5 wt%) to provide good resistance to high temperature softening, 1 wt% Si to improve high temperature oxidation resistance, and small molybdenum and vanadium additions (about 1%) that form stable carbides to increase resistance to erosive wear 8. Composition analysis was performed on H13 tool steel before and after spray forming. Results, summarized in Table 1, indicate no significant variation in alloy additions. Table 1. Composition of H13 tool steel Element C Mn Cr Mo V Si Fe Stock H13 0.41 0.39 5.15 1.41 0.9 1.06 Bal. Spray Formed H13 0.41 0.38 5.10 1.42 0.9 1.08 Bal. Microstructure The size, shape, type, and distribution of carbides found in H13 tool steel is dictated by the processing method and heat treatment. Normally the commercial steel is machined in the mill annealed condition and heat treated (austenitized/quenched/tempered) prior to use. It is typically austenitized at about 1010C, quenched in air or oil, and carefully tempered two or three times at 540 to 650C to obtain the required combination of hardness, thermal fatigue resistance, and toughness. Commercial, forged, ferritic tool steels cannot be precipitation hardened because after electroslag remelting at the steel mill, ingots are cast that cool slowly and form coarse carbides. In contrast, rapid solidification of H13 tool steel causes alloying additions to remain largely in solution and to be more uniformly distributed in the matrix 9-11. Properties can be tailored by artificial aging or conventional heat treatment. A benefit of artificial aging is that it bypasses the specific volume changes that occur during conventional heat treatment that can lead to tool distortion. These specific volume changes occur as the matrix phase transforms from ferrite to austenite to tempered martensite and must be accounted for in the original mold design. However, they cannot always be reliably predicted. Thin sections in the insert, which may be desirable from a design and production standpoint, are oftentimes not included as the material has a tendency to slump during austenitization or distort 8 during quenching. Tool distortion is not observed during artificial aging of spray-formed tool steels because there is no phase transformation. An optical photomicrograph of spray-formed H13 is shown in Figure 5 together with an SEM image, in backscattered electron (BSE) mode. Energy dispersive spectroscopic (EDS) composition analysis of some features in the photomicrographs is also given. While exact quantitative data is not possible due to sampling volume limitations, results suggest that grain boundaries are particularly rich in V. Intragranular (matrix) regions are homogeneous and rich in Fe. X-ray diffraction analysis indicates that the matrix phase is primarily ferrite (bainite) with very little retained austenite, and that the alloying elements are largely in solution. Discrete intragranular carbides are relatively rare, very small (about 0.1 m) and predominately vanadium-rich MC carbides. M 2 C carbides are not observed. Element Si V Cr Mn Mo Fe Spot #1 (wt%) 0.61 32.13 6.68 0.17 2.05 58.36 Spot #2 (wt%) 1.59 0.79 5.35 0.28 2.28 89.72 Figure 5. Photomicrographs of as-deposited H13 tool steel. 3% nital etch. (a) Optical photomicrograph. (b) SEM image (BSE mode) near a grain boundary. Table gives EDS composition of numbered features. 9 Figure 6 illustrates the microstructure of spray-formed H13 aged at 500C for 1 hr. During aging, grain boundaries remain well defined, perhaps coarsening slightly compared to as- deposited H13 (Figure 5). The most prominent change is the appearance of very fine (0.1 m diameter) vanadium-rich MC carbide precipitates. The precipitates are uniformly distributed throughout the matrix and increase the hardness and wear resistance of the tool steel. Increasing the soak temperature to 700C results in prominent carbide coarsening, the formation of M 7 C 3 and M 6 C carbides, and a decrease in hardness. The photomicrographs of Figure 7 illustrate the dramatic change in carbide size. BSE imaging clearly differentiates Mo/Cr-rich carbides from V-rich carbides, shown as light and dark areas, respectively, in Figure 7. EDS analysis of these carbides is also given in Figure 7. Element Si V Cr Mn Mo Fe Spot #1 (wt%) 0.06 13.80 7.20 2.64 2.44 73.86 Spot #2 (wt%) 1.52 0.82 5.48 0.23 2.38 89.57 Figure 6. Photomicrographs of spray-formed/aged H13 tool steel. 500C soak for 1 hr. 3% nital etch. (a) Optical photomicrograph. (b) SEM image (BSE mode) near a grain boundary. Table gives EDS composition of numbered features. 10 Element Si V Cr Mn Mo Fe Spot #1 (wt%) 0 82.27 9.01 0 4.33 4.39 Spot #2 (wt%) 0 5.30 25.70 0 55.55 13.45 Spot #3 (wt%) 1.60 0.88 6.32 0.28 2.92 88.00 Figure 7. SEM Photomicrograph (BSE mode) of spray-formed/aged H13 tool steel showing adjacent V-rich (dark) and Mo/Cr-rich (light) carbides. 700C soak for 1/2 hr, 3% nital etch. Table gives EDS composition of numbered features. Material Properties Porosity in spray-formed metals depends on processing conditions. The average as-deposited density of spray-formed H13 was 98-99% of theoretical, as measured by water displacement using Archimedes principle. As-deposited hardness was typically about 59 HRC, harder than commercial forged and heat treated material (28 to 53 HRC depending on tempering temperature), and significantly harder than annealed H13 (200 HB). The high hardness is attributable to lattice strain due to quenching stresses and supersaturation. As shown in Figure 8, hardness can be varied over a wide range by artificial aging. 59 HRC as- deposited samples were given isochronal (1 hr) soaks at 50C increments from 400 to 700C, air cooled, and evaluated for microhardness. At 400C, a small decrease in hardness was observed, presumably due to stress relieving. As the soak temperature was further increased, hardness rose to a peak hardness of approximately 62 HRC at 500C. Higher soak temperature resulted in a drop in hardness as carbide particles coarsened. Peak age hardness in spray-formed H13 tool steel is notably higher than that of commercial hardened material. Normally, commercial H13 dies used in die casting are tempered to about 40 to 45 HRC as a tradeoff since high hardness dies, while desirable for wear resistance, are prone to premature failure via thermal fatigue as the dies surface is rapidly cycled from 300C to 700C during aluminum production runs. 11 Figure 8. Hardness of artificially aged spray-formed H13 tool steel following one hour soaks at temperature. Hardness range of conventionally heat treated H13 included for comparison. As-deposited spray-formed material was also hardened following the conventional heat treatment cycle used with commercial material. Samples of forged/mill annealed commercial and spray- formed materials were austenitized at 1010C, air quenched, and double tempered (2 hr plus 2 hr) at (538C). The microstructure in both cases was found to be tempered martensite with a few spheroidal particles of alloy carbide. Hardness values for both materials were very nearly identical. Table 2 gives the ultimate tensile strength and yield strength of spray-formed, cast, and forged/heat treated H13 tool steel measured at test temperatures of 22 and 550C. Values for spray formed H13 are given in the as-deposited condition and following artificial aging and conventional heat treatments. Values for the spray-formed material are comparable to those of forged and are considerably higher than those of cast tool steel. The spray-formed material seems to retain its strength somewhat better than forged/heat treated H13 at higher temperatures. 12 Table 2. H13 tool steel mechanical properties. Sample/Heat Treatment Ultimate Tensile Strength (MPa) Yield Strength (MPa) Test Temperature (C) Spray formed/as-deposited 1061 951