On the Multilayered Chip-Type PTC Elements Prepared by Roll-Forming Process

2007 ◽  
Vol 336-338 ◽  
pp. 661-664
Author(s):  
Huan Liu ◽  
Shu Ping Gong ◽  
Dong Xiang Zhou
Keyword(s):  
Multilayer Structure ◽  
Room Temperature ◽  
Roll Forming ◽  
Forming Process ◽  
Temperature Resistance ◽  
Typical Size ◽  
Firing Schedule ◽  
Chip Type ◽  
Bonding Method ◽  
Roll Forming Process

We describe the fabrication of chip-type PTC elements (BaTiO3-based) by roll-forming process. Crack-free green tapes with good malleability are successfully obtained with the thickness typically in the range of 0.20~1.0mm. We also focus on reducing the room-temperature resistance of the chip-type PTC element without deteriorating its PTC effect, both by controlling the firing schedule and by introducing multilayer structure with electrode-bonding method. The typical size of the 5-layered chip-type PTC sample obtained is 8.0mm×5.0mm×1.95mm with R25=1.97- and Rmax/Rmin=4.8×105.

Preparation of Multilayer Barium Titanate PTC Thermistor with Low Room Temperature Resistance

2007 ◽  
Vol 280-283 ◽  
pp. 1921-1924 ◽  
Author(s):  
Dong Xiang Zhou ◽  
Huan Liu ◽  
Shu Ping Gong ◽  
Dao Li Zhang
Keyword(s):  
Barium Titanate ◽  
Room Temperature ◽  
Roll Forming ◽  
Forming Process ◽  
Sintered Ceramic ◽  
Temperature Resistance ◽  
Typical Size ◽  
Temperature Characteristics ◽  
Chip Type ◽  
Roll Forming Process

Chip-type PTC thermistors with multilayer stacked structure have been fabricated by bonding sintered ceramic chips with internal electrodes to offer low resistance at room temperature and correspondence to surface mounted technology. The resistance-temperature characteristics of multiplayer stacked PTC thermistors made up of different numbers (N = 1, 3, 5) of layers were experimentally investigated (the typical size of each layer was 10 mm × 7.0 mm × 0.38 mm). The selection and extraction of additives in roll-forming process were also discussed. This resulted in a crack-free multiplayer stacked PTC thermistor.

Computerized Numerical Simulation of Roll-Forming Process

CIRP Annals ◽  
1995 ◽  
Vol 44 (1) ◽  
pp. 239-242 ◽  
Author(s):  
Manabu Kiuchi ◽  
Kenji Abe ◽  
Ryu Onodera
Keyword(s):  
Numerical Simulation ◽  
Roll Forming ◽  
Forming Process ◽  
Roll Forming Process

Quadrilateral Shape Rib Forming by Roll Forming Process

2018 ◽  
Vol 878 ◽  
pp. 296-301
Author(s):  
Dong Won Jung
Keyword(s):  
Automotive Industry ◽  
High Strength Steel ◽  
Numerical Study ◽  
Thickness Distribution ◽  
High Strength ◽  
Metal Sheet ◽  
Product Performance ◽  
Roll Forming ◽  
Forming Process ◽  
Roll Forming Process

The roll forming is one of the simplest manufacturing processes for meeting the continued needs of various industries. The roll forming is increasingly used in the automotive industry to form High Strength Steel (HSS) and Advanced High Strength Steel (AHSS) for making structural components. In order to reduce the thinning of the sheet product, traditionally the roll forming has been suggested instead of the stamping process. The increased product performance, higher quality, and the lowest cost with other advantages have made roll forming processes suitable to form any shapes in the sheets. In this numerical study, a Finite Element Method is applied to estimate the stress, strain and the thickness distribution in the metal sheet with quadrilateral shape, ribs formed by the 11 steps roll forming processes using a validated model. The metal sheet of size 1,000 × 662 × 1.6 mm taken from SGHS steel was used to form the quadrilateral shape ribs on it by the roll forming process. The simulation results of the 11 step roll forming show that the stress distribution was almost uniform and the strain distribution was concentrated on the ribs. The maximum thinning strain was observed in the order of 15.5 % in the middle rib region possibly due to the least degree of freedom of the material.

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