Effect of Cu Content on the Formability and Portevin-Le Chatelier Effect of Al-Mg Alloys

2015 ◽  
Vol 817 ◽  
pp. 150-157
Author(s):  
Peng Cheng Ma ◽  
Di Zhang ◽  
Lin Zhong Zhuang ◽  
Ji Shan Zhang

Al-Mg alloys developed for auto body sheets with different Cu contents were fabricated in the laboratory scale. The effects of Cu content on the microstructures, formability and Portevin–Le Chatelier(PLC) effect of the alloys were investigated by polarizied optical microscopy and room temperature tensile testing. It has been found that with increasing Cu content, there was little change of the strain hardening exponent, but the plastic strain ratio and limiting drawing ratio increased firstly and then decreased. A quantitative statistical analysis of the characteristics of the PLC effect was made, including the stress drop and the reloading time, which follow a common linear relationship with plastic strain, and the increase rate of stress drop and reloading time was bigger with more Cu content. A detailed discussion of the corresponding mechanism of Cu and Cu-containing precipitates on the dynamic strain aging(DSA) was made.

2014 ◽  
Vol 886 ◽  
pp. 3-6
Author(s):  
Zu Jian Yu ◽  
Jian Hui Li ◽  
Yan Yang

Tensile tests and a cold deep drawing process were developed at room temperature to estimate the stamping formability of AZ31B magnesium alloy sheet. The results show that AZ31B magnesium alloy sheet has poor formability at room temperature with the total elongation of ~ 20%, the yield ratio is about 0.6 and the strain-hardening exponent is 0.18, while the plastic strain ratio is 1.58, and the earing ratio is-0.55.Thus, AZ31B magnesium alloy sheet can not suffer server plastic deformation. It was found that comparatively shallow magnesium alloy cups were satisfactorily formed at room temperature without heating when the punch fillet radius 6mm and the die fillet radius10mm with a 1mm thickness sheet with limit drawing ratio of 1.25.


2018 ◽  
Vol 9 (1) ◽  
pp. 335-346
Author(s):  
Norman Iskandar ◽  
Deni Fajar Fitriyana ◽  
Fuad Arief Raharjo

Pedal Brake berfungsi sebagai tempat pijakan kaki pada sistem pengereman pada salah satu produk motor roda tiga di Indonesia. Pembuatan pedal brake menggunakan proses drawing yaitu proses dimana gaya diberikan pada benda kerja agar terdeformasi plastis mengikuti bentuk dari punch dengan kedalaman tertentu. Dalam pembuatan pedal brake menggunakan proses drawing terdapat potensi cacat yang bisa terjadi akibat  besarnya gaya  serta tingkat  kedalaman cetakan.  Analisa  draw ability  dilakukan untuk mengetahui seberapa besar kedalaman proses drawing sebelum benda kerja mengalami kegagalan dengan menghitung nilai Limiting Drawing Ratio (LDR) dan rata-rata plastic strain ratio (Ravg). Simulasi dilakukan untuk mengetahui parameter seperti gaya pembentukan, jumlah energi yang digunakan beserta potensi cacat yang timbul pada pedal brake seperti earing dan kegagalan pada saat melakukan proses drawing. Dari hasil perhitungan LDR sebesar 1,028 dan Ravg  sebesar 2,8 untuk jenis material ST-37 menunjukkan bahwa kemampuan draw ability yang rendah dengan gaya pembentukan maksimum sebesar 92,8 kN dan energi yang diserap sebesar 0,69 kJ. Nilai Ravg sebesar 1,2 untuk jenis material ST-37 cukup besar sehingga potensi terjadinya earing tidak terlalu nampak untuk proses drawing. Perbandingan antara analisa teoritis dan simulasi memiliki error sebesar 6% sehingga hasil masih dapat dikatakan valid.


2011 ◽  
Vol 399-401 ◽  
pp. 148-151
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao

Hot rolled 260MPa grade high strength Nb-IF steel sheet was used to study the effect of coiling temperature and cold reduction ratio on the microstructures and mechanical properties. The experimental results showed that the recrystallization has finished. Under 650°Ccoiling temperature and 75% cold reduction ratio, and under 600°C or 700°C coiling temperature and 65% cold reduction ratio, the plastic strain ratio r value and the strain hardening exponent n value were reached the maximum, and respectively, the r value was approximate 1.8, the n value was approximate 0.26. That obtains optimally match of high strength and punching property.


2018 ◽  
Vol 21 (4) ◽  
pp. 314-319 ◽  
Author(s):  
T. V. Tretyakova ◽  
V. E. Wildemann

2010 ◽  
Vol 30 (12) ◽  
pp. 3515-3523
Author(s):  
叶南 Ye Nan ◽  
张丽艳 Zhang Liyan

2010 ◽  
Vol 638-642 ◽  
pp. 356-361 ◽  
Author(s):  
Ni Tian ◽  
Gang Zhao ◽  
Liang Zuo ◽  
Chun Ming Liu

The texture, the formability and the correlation between formability indices of Al-0.9Mg- 1.0Si-0.7Cu-0.6Mn alloy for automotive body sheets subjected to solid solution, T4, annealing treatment and artificial aging at 443k for different time were investigated by orientation distribution functions(ODF) analysis, tensile and cupping test, FLD measurement and regression analysis method. The results showed that the textures of cold rolled alloy sheets consist mainly of copper and brass orientations, which are transformed into the texture mainly containing {001}<310> orientation after recrystallization, and aging treatment has little influence on the recrystallization texture. The formability of alloy sheets subjected to solid solution, T4 and annealing treatment is similar, however, the formability was observably deteriorated after aging at 443k. The correlation between uniform elongation δu and FLD0 is the most remarkable in all the given formability indices, the correlation between strain-hardening exponent n and the FLD0 take second place, while there is no correlation between plastic strain ratio r and FLD0. The correlation between reduction of area ψ and cupping value IE is distinct, while ψ and IE have little correlation with FLD0.


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