摘要
目的降低铝合金手机外壳阳极异色发白不良品率。方法基于6σ管理中的DMAIC体系,结合某款手机外壳加工工艺,根据返工流程图和关键因子的因果关系图,制作出因子CE矩阵并进行PFMEA分析,确定R400酸洗槽中的药剂浓度、超声波频率、槽液温度、浸泡时间、烘干槽中热风洁净度5个关键质量影响因子。采用五五研究法,针对烘干槽空气滤芯不定期更换或是长期一个月以上不更换、吹出的热风洁净度低,导致产品异色等问题,制定空气滤芯更换时间标准。采用两水平四因子试验设计,得出异色发白的不良率随药剂浓度的增大而增大,随槽液温度、浸泡时间、超声波频率的增大而减小,槽液温度和药剂浓度有交互作用。并设计了R400酸洗槽中的药剂浓度、超声波频率、槽液温度、浸泡时间四个因素的控制策略。结果酸洗槽各参数的取值范围为:药剂质量浓度35~40 g/L,超声波频率3.5 A,槽液温度25~27℃,浸泡时间3.5~4 min。烘干槽更换时间规则:每15 d更换一次,每5 d检查空气滤芯的洁净度。结论异色发白不良率由改善前的平均6.63%降低至1.14%,达到了2%的目标要求,4周成本降低90多万元。
The work aims to reduce the negative discoloring and whitening rate of anode in aluminum alloy mobile phone shell. CE matrix of factor was prepared and PEMEA analysis was executed based on DMAIC system in six sigma management and processing technology of some certain mobile phone shell according to causal graph between rework flowchart and key factor. Then, 5 key quality influence factors were determined, including drug concentration, ultrasonic frequency, tank liquor temperature and soaking time R400 support pickling tank and hot air cleanliness in drying tank. Equally study method was adopted to solve problems like air filter element in drying tank not being regularly replaced or not replaced over one month, low cleanliness of blown hot air and discoloring of products and the replacement standard of air filter was prepared. Through two-level four factorial experiment design, the negative discoloring and whitening rate increased as the drug concentration went up, but decreased along with increase of tank liquor temperature, soaking time and ultrasonic frequency increase. Tank liquor temperature and drug concentration were interacted. Then, the control strategy of the drug concentration, ultrasonic frequency, tank liquor temperature and soaking time of the R400 support pickling tank was designed. The range of each parameter of pickling tank： drug concentration from 35 g/L to 40 g/L, ultrasonic frequency 3.5 A, tank liquor temperature from 25 ℃ to 27 ℃ and soaking time from 3.5 min to 4 min. The rules on replacement time of the drying tank： replacement every 15 days and inspection for cleanliness of air filter element every 5 days. The negative discoloring and whitening rate drops to 1.14% from 6.63% before the improvement and reaches the target of 2%. Cost decreased by more than 900,000 Yuan for 4 weeks.
作者
王秀红
许博蕴
葛庆洋
WANG Xiu-hong, XU Bo-yun, GE Qing-yang(Zhengzhou University of Aeronautics, Zhengzhou 450015, Chin)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2018年第5期290-301,共12页
Surface Technology
基金
国家自然科学基金(61203179)
河南省哲学社会科学规划项目(2016BZH010)
河南省科技厅项目(182102310951)~~
关键词
阳极异色发白
6σ
DMAIC
阳极氧化
铝合金
酸洗
anode discoloring and whitening
6σ
DMAIC
anodic oxidation
aluminum alloy
pickling
