Investigation of deep drawing of lightweight bimetallic Al1050/SS304 sandwich composite cup

The effect of geometrical and process parameters on the deep drawing behavior of Aluminium (Al1050)/Steel (SS304) bimetallic axis-symmetric sandwich composite cup is analyzed by using numerical and experimental approaches. The parameters are selected focusing on the elimination of defects like thinning, thickening, tearing, and wrinkling. The explicit deep drawing analysis of the cylindrical cup is carried out by using the finite element software package. The obtained numerical results are utilized for the optimization and identification of significantly influencing parameters using Taguchi and ANOVA techniques and further validated by performing an experimental test. The effectiveness in the utilization of the Al1050/SS304 sandwich composite sheet for deep drawing of cups is proved by comparing it with the deep drawing of the SS304 sheet. The results suggest that the sandwich composite cup under investigation can be drawn successfully with the higher limiting drawing ratio and low thickness variation. The obtained maximum limiting drawing ratio (2.08) showed that the higher formability of the Al1050/SS304 sandwich composite sheet is possible by a sandwich of the SS304 sheet with an Al1050 sheet.

Multi Draw Radius Die Design for Increases in Limiting Drawing Ratio

As a major sheet metal process for fabricating cup or box shapes, the deep drawing process is commonly applied in various industrial fields, such as those involving the manufacture of household utensils, medical equipment, electronics, and automobile parts. The limiting drawing ratio (LDR) is the main barrier to increasing the formability and production rate as well as to decrease production cost and time. In the present research, the multi draw radius (MDR) die was proposed to increase LDR. The finite element method (FEM) was used as a tool to illustrate the principle of MDR based on material flow. The results revealed that MDR die could reduce the non-axisymmetric material flow on flange and the asymmetry of the flange during the deep drawing process. Based on this material flow characteristic, the cup wall stretching and fracture could be delayed. Furthermore, the cup wall thicknesses of the deep drawn parts obtained by MDR die application were more uniform in each direction along the plane, at 45°, and at 90° to the rolling direction than those obtained by conventional die application. In the present research, a proper design for the MDR was suggested to achieve functionality of the MDR die as related to each direction along the plane, at 45°, and at 90° to the rolling direction. The larger draw radius positioned for at 45° to the rolling direction and the smaller draw radius positioned for along the plane and at 90° to the rolling direction were recommended. Therefore, by using proper MDR die application, the drawing ratio could be increased to be 2.75, an increase in LDR of approximately 22.22%.

The non-isothermal hot deep drawing of AA5083 aluminum alloy

The present work is focused on the hot deep drawing process for cylindrical 5083 aluminum alloy parts, by superimposing a thermal gradient between the blank center-flange region. The imprtance of application of forming processes at elevated temperatures, in improving the formability, has increasingly attracted attention in recent years. As a case study, the experimental and numerical tests were performed at three speeds (60, 200 and 378 mm min−1) from room temperature (RT) up to 0.9 melting point, inspired by the advent of extraordinary superplastic behavior of AA5083 in hot condition. In particular, the focus was on the effects of forming speed on punch load, thickness distribution, and earing behavior. Finite element simulations were run in order to investigate the limiting drawing ratio and temperature gradient. The tests highlight that by increasing the temperature, the number and the position of the ears are constant, while the height of ears decreases. Furthermore, limiting drawing ratio equal to 2.84 is reached at 550 °C.

ANALISIS PROSES DRAWING UNTUK PEMBUATAN PEDAL BRAKE SEPEDA MOTOR RODA TIGA DENGAN SOFTWARE BERBASIS FEM

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.

Quality control of blanks manufactured by metal forming

Current requirements to blanks manufactured by metal forming are presented. There are shown data on accuracy and surface roughness of rolled blanks. Different fracture criteria used for the analysis of press forming are analyzed. It is shown that metal tests on Eriksen should not be used for the estimate of the limiting drawing ratio.