壓鑄產(chǎn)品缺陷及改善方法

1、BDCProcessesDefects and Correction Fe1 You cant correct and control defects without first measuring and reporting them 要改善缺陷要改善缺陷, 必須先行紀(jì)錄必須先行紀(jì)錄, 統(tǒng)計(jì)及分析統(tǒng)計(jì)及分析 You have to install a scrap reporting system 設(shè)定一個(gè)紀(jì)錄系統(tǒng) It should be posted on the bulletin board so everyone can see it 應(yīng)在當(dāng)眼處張貼, 讓大家一起 參與 Basic p

2、rocedure 基本方法基本方法 BDCProcessesDefects and Correction Fe2 You have to install a rating system to check whether the defect problems are getting better or worse. 制定評(píng)估級(jí)別制定評(píng)估級(jí)別, 以了解問(wèn)以了解問(wèn) 題是否改善中題是否改善中 Bhler - Dataspeed Trendgraphic0004A.DAT 20406080100120140 # % 0 Cycles 0 1000 2000 3000 4000 5000 6000 70

3、00 8000 9000 10000 10 20 30 40 50 60 70 80 90 100 name of curveminmax unit Cyc tot* 010000Cycles l B * 0100mm t F * 0.0000.100s t Cyc * 0.0999.0s information of diagram file name of die program: 0004.pro designation of die : 0002 designation of casting : NVG004CAV#1 machine nr : 10298489 date / time

4、 : 27-11-98 15:58:37 cycle number : 4054 cycle attributes : ok 4054 25 .091 74.1 Basic procedure 基本方法基本方法 It must categorize scrap 必須將廢品分類必須將廢品分類 By defect type 缺陷種類 By part number 零件號(hào) By die 模具編號(hào) By shift 班次 By machine 設(shè)備編號(hào) By operator 操作員 BDCProcessesDefects and Correction Fe3 Cold flow 冷紋 Lap 層疊

5、Chill 冷隔 Non fill 不填滿 Cause: Leading edge of metal flow is too cold, laps together. 原因原因: 金屬前端溫度低金屬前端溫度低, 金屬出現(xiàn)層疊金屬出現(xiàn)層疊 Surface defects 表面缺陷表面缺陷 BDCProcessesDefects and Correction Fe4 Increase die temperature 提高模溫提高模溫 Too slow cycle time 週期太長(zhǎng) Excessive coolant flow 過(guò)度冷卻 Excessive spray 過(guò)量脫模噴塗 Add ove

6、rflows for 增加溢流塊 more heat Reduce fill time 縮短充填時(shí)間縮短充填時(shí)間 Increase plunger speed 提高沖頭速度 Increase plunger size 加大沖頭 Increase gate area 加大澆口面積 Surface defects 表面缺陷表面缺陷 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe5 Change flow pattern 改變金屬流向改變金屬流向 Direct flow to problem area by moving the

7、gate 改變澆口使金屬直接流向問(wèn)題區(qū)域 Change gate velocity 改變澆口速度 Add overflows to capture cold metal 增加溢流池以吸收冷端 Check for low metal temp. 檢查金屬溫度是否正常檢查金屬溫度是否正常 Low pressure at end of shot 填滿後壓力低填滿後壓力低 Flash around tip 沖頭配合不良, 出現(xiàn) 飛料 Poor sleeve conditions 料筒損耗太大 Too little sleeve lubrication 料筒注潤(rùn) 滑不足 Surface defects

8、表面缺陷表面缺陷 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe6 Thin biscuit 料餅太薄料餅太薄 Thin wall sections 薄壁件薄壁件 Minimum wall thickness 可實(shí)現(xiàn)壁厚 Design errors 設(shè)計(jì)錯(cuò)誤 Uneven wall thickness 壁厚不均 Tool making errors 模具制造錯(cuò)誤模具制造錯(cuò)誤 Heavy flashing 嚴(yán)重飛邊嚴(yán)重飛邊 Check also 請(qǐng)檢查請(qǐng)檢查: Vents open and sized correctly 排氣

9、是否合理 Vacuum working 真空輔助是否正常運(yùn)作真空輔助是否正常運(yùn)作 Corrections 改善方法改善方法 Surface defects 表面缺陷表面缺陷 BDCProcessesDefects and Correction Fe7 Gas porosity comes from 3 main sources in die casting 三大主要來(lái)源三大主要來(lái)源: Trapped air 捲入的空氣 Steam 過(guò)程中產(chǎn)生的蒸汽 Burned lubricant 蒸發(fā)的潤(rùn)滑劑蒸發(fā)的潤(rùn)滑劑 Cause 原因原因: Gas trapped in the metal flow d

10、uring die fill 充填過(guò)程中被金屬裹藏的氣體充填過(guò)程中被金屬裹藏的氣體 Gas porosity 氣孔氣孔 BDCProcessesDefects and Correction Fe8 Check for sources of trapped air 找尋氣體的來(lái)源找尋氣體的來(lái)源 Consistent pour rate and turbulence free pouring 均衡的給湯,盡量避免亂流 Delay after pouring 給湯後延時(shí) Acceleration to slow shot speed 注意低速時(shí)的增速率 Slow shot speed 減低充填速度

11、Accelerate to fast shot speed as late as possible 盡可能延時(shí)轉(zhuǎn)入二速盡可能延時(shí)轉(zhuǎn)入二速 Gas porosity 氣孔氣孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe9 Check runner for smooth flow path 檢查流道是否暢順檢查流道是否暢順 No sharp corner 無(wú)尖角 No blind ends 無(wú)死位 No sudden changing area in runner path 流道切面面積無(wú)突然變化流道切面面積無(wú)突然變化 Ga

12、s porosity 氣孔氣孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe10 Check overflow and vents 檢查溢流及排氣檢查溢流及排氣 Right size (big enough) 尺寸合理 (足夠空間) Vents kept open 排氣無(wú)阻塞 Located at the last point to fill 安排在最後充填位置 Use computer simulation and fill test 利用電腦模擬查證利用電腦模擬查證 Gas porosity 氣孔氣孔 Correcti

13、ons 改善方法改善方法 BDCProcessesDefects and Correction Fe11 Vacuum working 真空輔助是否正常運(yùn)作真空輔助是否正常運(yùn)作 Vacuum channels big enough 真空排氣通道足夠 Vacuum channels located at last point to fill 真空通道在充填最後位置 Vacuum valves working 真空閥工作正常 Vacuum level adequate 真空壓力在工作範(fàn)圍內(nèi) Gas porosity 氣孔氣孔 Corrections 改善方法改善方法 BDCProcessesDef

14、ects and Correction Fe12 Check for steam (water on die) 蒸汽蒸汽 (模具表面的水模具表面的水) Check that die is dry when it closes 在合模前表面無(wú)水份殘留 Use lots of air blow 用壓縮空氣吹干 Check for water leaks 檢查有否漏水現(xiàn)象 Look for leaks from sprayer 噴塗機(jī)漏水 Gas porosity 氣孔氣孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe13 Lo

15、ok for excessive plunger lubricant 沖頭潤(rùn)滑劑是否過(guò)量沖頭潤(rùn)滑劑是否過(guò)量 Try to avoid putting lubricant in front of the tip 不可將潤(rùn)滑劑塗在沖頭前端 Look for consistent application procedures 維持一個(gè)穩(wěn)定及定量過(guò)程 Look for excessive die lub or anti-solder paste 注意是否存在其他脫模劑殘留注意是否存在其他脫模劑殘留 Gas porosity 氣孔氣孔 Corrections 改善方法改善方法 BDCProcessesD

16、efects and Correction Fe14 Aluminum and magnesium 鋁 和鎂合金 : The solid metal takes 4% to 6% less space than the liquid metal 收縮率一般在 4 6% Cause 產(chǎn)生主因產(chǎn)生主因: Cast material takes up less space when solid than when liquid 金屬在固化時(shí)體積減少金屬在固化時(shí)體積減少 Shrinkage porosity 縮孔縮孔 BDCProcessesDefects and Correction Fe15 In

17、crease pressure during solidification 增加保壓壓力增加保壓壓力 The final pressure has to follow the skin solidification 最終金屬壓力緊接表面固化最終金屬壓力緊接表面固化 Shrinkage porosity 縮孔縮孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe16 Check for pressure Problems 檢查壓力問(wèn)題檢查壓力問(wèn)題 Intensifier pressure correct 增壓是否正常 Check

18、 Intensifier setting (rise time, pressure curve, switch over point) 檢查增壓設(shè)定 (建壓時(shí)間, 曲線及切 入點(diǎn)) Intensifier accumulator charged correctly 儲(chǔ)能器是否正常 Shrinkage porosity 縮孔縮孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe17 Plunger problems that reduce pressure 沖頭不良沖頭不良鎖鎖引至壓力減少引至壓力減少 Poor tip or s

19、leeve conditions 沖頭或料筒狀況不良 Soldering at end of sleeve 料筒未端出現(xiàn)熔合現(xiàn)象 Plunger or sleeve cooling not working 料筒或沖頭冷卻異常 Inadequate lubrication 潤(rùn)滑不足潤(rùn)滑不足 Shrinkage porosity 縮孔縮孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe18 Feed additional metal to troublespot 針對(duì)問(wèn)題部分增加金屬充填針對(duì)問(wèn)題部分增加金屬充填 Can sque

20、eze pins used? 可否使用擠壓銷可否使用擠壓銷 Can an additional gate be brought closer to trouble spot? 可否增加澆口至問(wèn)題點(diǎn)附近可否增加澆口至問(wèn)題點(diǎn)附近 Can the wall be made thicker between the gate and the trouble spot? 可否加大問(wèn)題點(diǎn)相連的澆口可否加大問(wèn)題點(diǎn)相連的澆口 Shrinkage porosity 縮孔縮孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe19 Check die

21、 temperature 檢查模溫檢查模溫 Heat up surrounding cold spots 對(duì)問(wèn)題黠加溫 Cool hot spots 冷卻高溫部份 Check temperature difference between die halves 檢查動(dòng)檢查動(dòng), 定模的溫差定模的溫差 Shrinkage porosity 縮孔縮孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe20 Thin biscuit or size varies too much 料餅太薄或產(chǎn)品尺寸變化太大 Check alloy 檢查金

22、屬 Check metal temperature fluctuations 金屬溫度是否穩(wěn)定 Use oriented part solidification 引導(dǎo)性冷卻產(chǎn)品 Use solidification simulation 固化模擬固化模擬, 找出問(wèn)題點(diǎn)找出問(wèn)題點(diǎn) Shrinkage porosity 縮孔縮孔 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe21 The main sources are usually poor melt cleaning and furnace cleaning practi

23、ces 主要雜質(zhì)來(lái)源是熔錬過(guò)程或主要雜質(zhì)來(lái)源是熔錬過(guò)程或 熔爐除污不良熔爐除污不良 Cause 引至原因引至原因: Inclusions are mostly oxides 主要是氧化物主要是氧化物 Inclusions 夾雜夾雜 BDCProcessesDefects and Correction Fe22 Check melting furnace cleaning procedures 檢討熔爐清潔方法檢討熔爐清潔方法 Examine melt line and corners for build up 檢查熔解過(guò)程中的死角或堆 積點(diǎn) Scrape bottom for excessiv

24、e corundum material on the bottom of furnace 注意沉渣, 必須徹底清除 Inclusions 夾雜夾雜 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe23 Check wall cleaning Procedures 檢討爐壁清理順序檢討爐壁清理順序 Proper tools 使用合適工具 Operators trained 充分培訓(xùn)操作員 Cleaning schedule maintained 嚴(yán)格執(zhí)行清理日程嚴(yán)格執(zhí)行清理日程 Check for a delay after c

25、leaning and before delivering metal 在處理金屬後應(yīng)靜置一定時(shí)間在處理金屬後應(yīng)靜置一定時(shí)間, 才可才可 轉(zhuǎn)運(yùn)使用轉(zhuǎn)運(yùn)使用 Inclusions 夾雜夾雜 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe24 Check fluxing procedures once/shift? 除渣劑使用管理 (頻率) Check degassing procedures 除氣是否可行 Check filter system 過(guò)濾是否可行 Review temperature at central melt

26、ing 中央熔解溫度控制 Check holding furnace for oxide build up and cleaning procedures 檢查保溫爐有否氧化物積聚及其清 理過(guò)程 Inclusions 夾雜夾雜 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe25 Aluminum and steel have a natural affinity for each other and naturally form intermetallic compounds given the chance. 鋁和鋼鐵有相

27、合性, 產(chǎn)生一種中間金屬促 成焊合情況出現(xiàn) This tendency is greatly accelerated when the die steel is at higher temperatures 此現(xiàn)象在模具處?kù)陡邷貢r(shí)更甚 Cause 產(chǎn)生原因產(chǎn)生原因: Aluminum and die steel combine and cast metal sticks to die surface 鋁與模具金屬結(jié)合鋁與模具金屬結(jié)合, 使合金熔液熔合在模具表面使合金熔液熔合在模具表面 Solder 焊合焊合 BDCProcessesDefects and Correction Fe26 Sol

28、der 焊合焊合 Corrections 改善方法改善方法 Check temperature in solder area, reduce if at all possible 注意焊合處溫度, 盡可能減低 Be sure waterlines are functioning 冷卻系統(tǒng)是否正常工作 Increase spray on the solder area 在事故點(diǎn)加強(qiáng)噴霧 Reduce speed, increase cycle time 減低充填速度, 加長(zhǎng)週期時(shí)間 Reduce fill time 減低充填時(shí)間 - Lower the length of time the me

29、tal impacts on the solder area 減少金屬與焊合點(diǎn)沖擊時(shí)間 BDCProcessesDefects and Correction Fe27 Check metal velocity - Is it too high? 檢查金屬速度是否太快 Check draft angle at solder point 焊合點(diǎn)接觸角是否太大 Check undercuts or rough surface on the die 模具表面有否缺損 Check iron content of alloy 留意合金中鐵含量 Use lower pressure if possible

30、如可能盡量減少壓力 Solder 焊合焊合 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe28 Die erosion 模具侵蝕 Cavitation 氣蝕 Burn out 燒損 Cause 產(chǎn)生原因產(chǎn)生原因 : High metal velocity, Bubbles in incoming metal, High oxide or silicon content in metal 金屬速度過(guò)高金屬速度過(guò)高, 熔液內(nèi)含氣量大熔液內(nèi)含氣量大, 熔液中氧化熔液中氧化 物或硅含量高物或硅含量高 Die erosion 模具侵蝕

31、模具侵蝕 BDCProcessesDefects and Correction Fe29 Check gate velocities 注意澆口速度 Check metal temperature, should not be to high 注意金屬溫度 Check die temperature in the gate area, 注意澆口溫度 - Reduce with spray or water cooling if possible 利用噴霧減低其溫度 Check metal cleanliness 注意金屬的處理, 減少夾雜 Check fill time - long fill

32、time accelerate gate erosion 注意充填時(shí)間 太長(zhǎng)會(huì)加快澆口侵蝕 Check alloy - hyper-eutectic alloys require smaller process window 注意合金 某些合金的處理區(qū)間較窄 Die erosion 模具侵蝕模具侵蝕 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe30 This defect occurs above all on thin wall parts 普遍在薄壁產(chǎn)品存在普遍在薄壁產(chǎn)品存在 Cause 產(chǎn)生原因產(chǎn)生原因: Many

33、operational and design issues 涉及多種的設(shè)計(jì)及操作因素涉及多種的設(shè)計(jì)及操作因素 Bending, warping 彎曲彎曲, 摟曲及變形摟曲及變形 BDCProcessesDefects and Correction Fe31 Design issues 設(shè)計(jì)原因設(shè)計(jì)原因 - Too much tolerance allowance for tool construction 模具設(shè)計(jì)中餘量太大 - Incorrect shrinkage 錯(cuò)誤評(píng)估收縮 - Incorrect estimate of process capability 錯(cuò)誤評(píng)估過(guò)程能力錯(cuò)誤評(píng)估過(guò)

34、程能力 Bending, warping 彎曲彎曲, 摟曲及變形摟曲及變形 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe32 Bending, warping 彎曲彎曲, 摟曲及變形摟曲及變形 Corrections 改善方法改善方法 Operational corrections 橾作上的改善橾作上的改善 - Consistent ejection temperature 頂出時(shí)溫度一致性 - Consistent process to keep consistent temperature 穩(wěn)定的過(guò)程以保持溫度一致 -

35、 Consistent spray 穩(wěn)定的噴霧 - Consistent cycle time 穩(wěn)定的週期 - Consistent cooling water flow rate 穩(wěn)定的冷卻控制 - Ejection too early 合適的頂出時(shí)間 BDCProcessesDefects and Correction Fe33 Bending, warping 彎曲彎曲, 摟曲及變形摟曲及變形 Operational corrections 操作改善操作改善 - Uneven ejector forces 不均頂出 - Poor ejector design or worn ejecto

36、r guide 頂出設(shè)計(jì)不合理或損壞 - Uneven length of bumper pins. 緩衝針長(zhǎng)度不均 - Incorrect ejector pin location 頂出位置錯(cuò)誤 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe34 Bending, warping 彎曲彎曲, 摟曲及變形摟曲及變形 Corrections 改善方法改善方法 Operational corrections 操作改善操作改善 - Stress on casting during die opening 開?？赡芤恋淖冃?- W

37、orn machine linkage 機(jī)鉸損耗, 開模不均 - Worn tie bar bushings 大桿軸套磨損 - Worn platen shoes 動(dòng)板墊板磨損 - No die support 模具托架的應(yīng)用 - Worn guide pins 模具導(dǎo)柱損耗 - Not enough draft allowance 出模角不足 BDCProcessesDefects and Correction Fe35 Cause 產(chǎn)生原因產(chǎn)生原因: Thermal conditions 溫度條件溫度條件 Poor die fit 模具不配合模具不配合 Poor machine locki

38、ng 設(shè)備鎖模問(wèn)題設(shè)備鎖模問(wèn)題 High impact peak at the end of die filling 充填沖擊充填沖擊 Flash 飛邊飛邊 BDCProcessesDefects and Correction Fe36 Thermal conditions 溫度條件溫度條件 Metal temperature too high 金屬溫度太高 Uneven heating, hot spots 加熱不均, 高溫點(diǎn)出現(xiàn) Be sure the hotter areas have cooling 確保高溫點(diǎn)有合理的冷卻 Die or metal temperatures fluct

39、uate from unstable conditions 過(guò)程不穩(wěn)定, 以致金屬及模 溫波動(dòng) Flash 飛邊飛邊 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe37 Die fit 模具配合模具配合 - Check die fit at operating temperature - die spotting 在工作溫度下檢查模 具的配合 印合 - Review die design for proper robustness 檢討模具設(shè)計(jì)是否牢固 Flash 飛邊飛邊 Corrections 改善方法改善方法 BDCP

40、rocessesDefects and Correction Fe38 Flash 飛邊飛邊 Corrections 改善方法改善方法 Machine locking conditions 鎖模裝置狀況鎖模裝置狀況 Strain tie bar for equal load 大桿是否平均受壓 Check condition of machine Linkage, tie bar bushings platen shoes, die set up correct, tie bar nuts not loose, platens not bent 設(shè)備狀況, 鉸鍵, 軸套, 墊板 模具固定, 大桿

41、螺母, 機(jī)板等 Die opening force centered on machine 開模力度在設(shè)備中心 BDCProcessesDefects and Correction Fe39 High impact peak 高沖擊高沖擊 Too high injection speed at the end of die filling - use deceleration 模具填滿時(shí)速度太高 - 減速 Intensifier comes too fast - use skin solidification 保壓轉(zhuǎn)換太早 表面固化引動(dòng) Flash 飛邊飛邊 Corrections 改善方法改

42、善方法 BDCProcessesDefects and Correction Fe40 Change flow pattern 改變金屬流向改變金屬流向 Direct flow to problem area by moving the gate 改變澆口使金屬直接流向問(wèn)題區(qū)域 Change gate velocity 改變澆口速度 Add overflows to capture cold metal 增加溢流池以吸收冷端 Check for low metal temp. 檢查金屬溫度是否正常檢查金屬溫度是否正常 Low pressure at end of shot 填滿後壓力低填滿後壓力低 Flash around tip 沖頭配合不良, 出現(xiàn) 飛料 Poor sleeve conditions 料筒損耗太大 Too little sleeve lubrication 料筒注潤(rùn) 滑不足 Surface defects 表面缺陷表面缺陷 Corrections 改善方法改善方法 BDCProcessesDefects and Correction Fe41 Check runner for smooth flow path 檢查流道是否暢順檢查流道是否暢順 No sharp corne