scholarly journals Die Material Selection Criteria for Aluminum Hot Stamping

2021 ◽  
Vol 5 (1) ◽  
pp. 15
Author(s):  
Maider Muro ◽  
Ines Aseguinolaza ◽  
Garikoitz Artola

The aim of this work is to develop a die material selection criterion for aluminum hot stamping applications. The criterion has been based on the back-to-back comparison of a set of reciprocating friction and wear tests. Three representatives belonging to different stamping die material families have been selected for the study: a cold work steel, a hot work steel, and a cast iron. These tool materials have been combined with an exemplary member from two heat treatable aluminum families: 2XXX and 6XXX. Each die-material/aluminum–alloy combination has been tested at three temperatures: 40, 200, and 450 °C. The temperatures have been selected according to different stamping scenarios: long takt time press quenching, short takt time press quenching, and very short takt time hot forming without quenching, respectively. The results show that, among the three die material options available, the cold work steel turned out to be the most favorable option for high volume production and long takt time, the hot work steel fitted best for high volume production coupled with short takt time, and cast iron turned to outstand for short runs with prototype dies and for hot stamping without die quenching.

Author(s):  
Phillip F. Myers

The successful development of small commercial turbogenerators for automotive and other applications presents a major economic challenge. Current aerospace turbogenerators in the 60 kilowatt power range sell for around $500 per kilowatt. Volume automotive turbogenerators prices must be $30 per kilowatt, or less — a 94% reduction. Turbogenerators for aerospace applications have drastically different requirements on almost all important criteria from automotive turbogenerators. The production of commercial turbogenerators requires a radically different organizational setting, mindset, and overhead structure from that necessary for the aerospace industry. Ground up designs which take an integrated approach to material selection, method of operation, fabrication techniques, supplier base, assembly methods, and low cost overheads will be necessary for commercial success. Significant innovation and simplification, and the natural effects of high volume production are also required. Success will likely require lean, agile, innovative, and specialized organizations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jort Hammer ◽  
Hidenori Matsukami ◽  
Satoshi Endo

AbstractChlorinated Paraffins (CPs) are high volume production chemicals and have been found in various organisms including humans and in environmental samples from remote regions. It is thus of great importance to understand the physical–chemical properties of CPs. In this study, gas chromatographic (GC) retention indexes (RIs) of 25 CP congeners were measured on various polar and nonpolar columns to investigate the relationships between the molecular structure and the partition properties. Retention measurements show that analytical standards of individual CPs often contain several stereoisomers. RI values show that chlorination pattern have a large influence on the polarity of CPs. Single Cl substitutions (–CHCl–, –CH2Cl) generally increase polarity of CPs. However, many consecutive –CHCl– units (e.g., 1,2,3,4,5,6-C11Cl6) increase polarity less than expected from the total number of –CHCl– units. Polyparameter linear free energy relationship descriptors show that polarity difference between CP congeners can be explained by the H-bond donating properties of CPs. RI values of CP congeners were predicted using the quantum chemically based prediction tool COSMOthermX. Predicted RI values correlate well with the experimental data (R2, 0.975–0.995), indicating that COSMOthermX can be used to accurately predict the retention of CP congeners on GC columns.


1986 ◽  
Vol 67 ◽  
Author(s):  
Chris R. Ito ◽  
M. Feng ◽  
V. K. Eu ◽  
H. B. Kim

ABSTRACTA high-volume epitaxial reactor has been used to investigate the feasibility for the production growth of GaAs on silicon substrates. The reactor is a customized system which has a maximum capacity of 39 three-inch diameter wafers and can accommodate substrates as large as eight inches in diameter. The MOCVD material growth technique was used to grow GaAs directly on p-type, (100) silicon substrates, three and five inches in diameter. The GaAs surfaces were textured with antiphase boundaries. Double-cyrstal rocking curve measurements showed single-cyrstal GaAs with an average FWHMof 520 arc seconds measured at four points over the wafer surface. Within-wafer thickness uniformity was ± 4% with a wafer-to-wafer uniformity of ± 2%. Photoluminescence spectra showed Tour peaks at 1.500, 1.483, 1.464, and 1.440 ev. Schottky diodes were fabricated on the GaAs on silicon material.


2017 ◽  
Vol 52 (3) ◽  
pp. 395-404
Author(s):  
Xiuqi Lyu ◽  
Jun Takahashi ◽  
Yi Wan ◽  
Isamu Ohsawa

Chopped carbon fiber tape-reinforced thermoplastic material is specifically developed for the high-volume production of lightweight automobiles. With excellent design processability and flexibility, the carbon fiber tape-reinforced thermoplastic material is manufactured by compressing large amounts of randomly oriented, pre-impregnated unidirectional tapes in a plane. Therefore, the carbon fiber tape-reinforced thermoplastic material presents transversely isotropic properties. Transverse shear effect along the thickness direction of carbon fiber tape-reinforced thermoplastic beam has a distinct influence on its flexural deformation. Accordingly, the Timoshenko beam theory combined with vibration frequencies was proposed to determine the set of transverse flexural and shear moduli. Meanwhile, the transverse flexural and shear moduli of carbon fiber tape-reinforced thermoplastic beam were finally determined by fitting all the first seven measured and calculated eigenfrequencies with the least squares criterion. In addition, the suggested thickness to length ratio for the 3-point bending test and Euler–Bernoulli model was given.


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