Automotive Weight Reduction Expo 2014 (Part 1)

High-strength steel sheets, lightweight metals, and 3D Printing

2014/02/24

Summary

White body of Honda Fit
White body of Honda Fit exhibited by H-ONE

 The Automotive Weight Reduction Expo 2014 was held at the Tokyo Big Sight on January 15th to 17th, 2014 as part of the Automotive World 2014. Excitement was felt at the venue, which was attended by a larger number of visitors than the previous year. In particular, the resin-related booth, which was placed near the entrance of the venue, attracted a considerable number of visitors.

 This report will first introduce the exhibition of frame parts using ultrahigh-strength steel sheet by H-ONE and ArcelorMittal. It will then focus on the exhibition of lightweight metals, such as magnesium and aluminum, and laminated molding method by using 3D data (3D printer). The second report, which will be coming shortly, will focus on weight-reducing techniques using plastics.


 

Related Reports:
EV & HEV Drive System Technology Expo 2014 (Feb. 2014)

Automotive Weight Reduction Expo 2013
(1) 3D additive manufacturing and lightweight metal use
(2) CFRP and other plastics improve weight reduction



Ultrahigh-strength steel sheet: H-ONE and ArcelorMittal

H-ONE

Fit's white body H-ONE has received an order for the white body (including doors and hoods) of Honda's third-generation Fit. Of the overall number of parts and weight of the vehicle, it accounts for 34% and 30% respectively. The parts supplier exhibited the left-front part of the white body.
Honda Fit Front-wheel house
Part of the white body of the third-generation Honda Fit Front-wheel house of the Fit's white body. By increasing an additional spot welding (pointed out by the ruler), H-ONE was able to reduce the wall thickness by 0.1mm.
The front-side frame
The front-side frame is made by combining steel plates of different strengths using the tailored blank method. The left side of the light black line in the center (front side of the vehicle) uses the 590 MPa UHSS material and the right side (rear side of the vehicle) uses the 780 MPa UHSS material.

 

Ultrahigh-strength steel sheet (UHSS)cold-forging technology The company showcased its Ultrahigh-Strength Steel Sheet (UHSS) cold-forging technology. At the exhibition, it introduced the employment of UHSS for the B-pillar. In the 2004 model, the B-pillar weighed as heavy as 5.8 kg because the 590 MPa UHSS was used and it needed a reinforcement material. In the 2010 model, H-ONE was able to rid of the reinforcement material from the B-pillar by using the 980 MPa UHSS. As a result, the B-pillar reduced its weight by 37% to 3.7 kg. H-ONE is considering the use of the 1,180 MPa UHSS at present that will enable a further 10% weight reduction. Cold-forging is characterized by a molding time of five times shorter than hot stamping.
Prototype B-pillar
Prototype B-pillar that is made of the 1,470 MPa UHSS and exhibited by H-ONE. It has reportedly not been completed in precision but no crevice was observed so far.

 

ArcelorMittal

S-in Motion This is a product collection of steel parts and solutions for weight reduction of auto parts that was proposed by ArcelorMittal. It has 43 solutions for the C-segment vehicle.
S-in Motion B-pillar This B-pillar is shaped by hot stamping using the laser-welding blank method. The weight has been reduced by 11% to 4.9 kg. It is made of a steel material with high strength (Usibor) in the upper area and of a steel material with excellent energy absorbency (Ductibor) in the lower area to enable both high strength and shock absorbency.
Door frame The front-door frame is shaped by hot stamping. It consists of four different thicknesses and is made of strong steel materials. It is provided for Honda's Accord and Acura MDX.
Development of lightweight steel door ArcelorMittal developed a lightweight door (13.3 kg) that is lighter than the existing front door (18.3 kg) by 27%. It was made lighter in weight by using ultrahigh-strength steel sheet with a tensile strength of 1,300 MPa or higher for 14% of the total steel. It is lighter than the S-in Motion series doors (14.5 kg). A much lighter door (12 kg) is under development.
S-in Motion B-pillar Front door frame
S-in Motion B-pillar Front door frame

 

 



Use of magnesium: NNH and KURIMOTO

NNH: Magnesium die cast

Steering cored bar made of magnesium die cast NNH, which supplies magnesium die casts for electric appliances, exhibited cored bars for steering. The magnesium die casts are supplied for the Toyota Prius, Nissan's vehicles, and Honda's vehicles.
According to NNH, magnesium is lighter than aluminum and better in processability and vibration absorption. Its disadvantages are in that it needs surface treatment for corrosion resistance and in that the melt magnesium and the facetted magnesium are combustible. The material cost is higher than aluminum by 1.5 times.

Steering cored bar made of magnesium die cast

Characteristics of magnesium alloy
Specific gravity Force difference required
for machining
Bending strength
and solidity
Impact resistance
Mg (alloy) 1.8 Mg (alloy)=1 ☆☆☆ ☆☆☆
Al (alloy) 2.7 Al(alloy)=1.8 ☆☆ ☆☆
Fe 7.9 Fe=6.3

Source: Prepared by MarkLines. It is based on data distributed by NNH.

 

KURIMOTO: Fire-retardant and heat-resistant magnesium alloy for casting under development

Fire-retardant and heat-resistant magnesium alloy for casting KURIMOTO developed a flame-retardant and heat-resistant magnesium alloy. It is resistant to heat up to 200℃ and ignitable at about 1,000 ℃, and thus it is not ignitable even in a dissolved state. It was proposed as an alternate material for aluminum material and engineering plastics. The cost and durability remains to be solved for commercial viability.

 

 



Weight reduction technologies for other metals: Fukai Manufacturing and Daido Kogyo

Fukai Manufacturing: Emboss forming technology, "embrella"

Honeycomb array emboss forming technology for metal sheets "embrella" Fukai Manufacturing showcased its technology of maintaining solidity while thinning the wall thickness by embossing honeycomb (alveolate) on metal sheets. Compared with a plate of 0.5 mm in thickness, the embossed plate of 0.35 mm in thickness can maintain its stiffness at 97% while reducing its weight at 70%. This technology also reduces material cost by using thin plates.
This processing is enabled by leaving small gaps in the mold of parts made from plates. The same processing is applicable for iron and stainless steel as well as for alminum. The company has patented this technology and also hopes to license it.
This technology has been adopted for the battery cover of the Subaru XV HYBRID and the floor heat shield panel of the Mitsubishi Outlander PHEV. It has been also adopted for the heat shield panel of the light-duty truck, Dost, of Ashok Leyland in India through licensing.
Battery cover supplied for the Subaru XV Crosstrek HYBRID Heat shield panel of the light-duty truck, Dost
Battery cover supplied for the Subaru XV HYBRID Heat shield panel of the light-duty truck, Dost, produced by Ashok Leyland through licensing

Daido Kogyo: Reducing weight and friction of silent chain

Weight reduction of silent chain The silent chain, which is used as a timing chain used to drive the engine cam shaft, was reduced in weight. The weight per strength was reduced by 15% from the conventional product. The chain was made lighter by optimizing the wall thickness, shape, and production method of the plate part by providing special surface finishing on the pin parts of the chain. This chain has been adopted for the timing chain and the oil pump chain of the 2.0 L in-line four-cylinder turbo engine mounted on the high-end sedan, Hongqi H7, of First Automobile Works.
Low-friction chain Daido has also developed a low-friction chain with the frictional resistance reduced by providing a process of rounding the back face of the chain (R shaping) and polishing. It is mounted on the 660 cc engines of Honda's mini vehicles: N-BOX, N-ONE, and N-WGN.
Daido Kogyo supplies a set of chain system for the 2.0L turbo engine of First Automotive Works Low friction chain
Daido Kogyo supplies a set of chain system for the 2.0L turbo engine of First Automobile Works. The right photo shows a list of the company's silent chains. Low friction chain supplied for Honda's N series mini vehicles

 

 



Laminated molding method by using 3D data

Aspect

Aspect sells  large sintering additive manufacturing system, RaFaEl, which the company developed in-house and provides molding services using this system. Its RaFaEl series is applicable to nylon 12 and its derivatives containing glass beads, glass fibers, and carbon fibers. It is also applicable to nylon 11, polypropylene, polystyrene, and synthetic rubber. The company has completed a prototype made of titanium alloy that has not been completed in precision.
According to the spokesman of the company, the products prepared by the 3D printer are intended only for analysis of shapes in trial production and small-lot production. They are not appropriate for production of parts or dies for production vehicles.

Powder bed melting/bonding system

Product name Work size CO2 laser beam diameter Remarks
RaFaEl 550 550×550×500 0.48mm The increased work size enables the forming of large component parts, such as wheel and intake manifold, without dividing them. The difficulty in temperature control in the molding area resulting from the increase of the work size has been compensated by newly installing a base heater.
RaFaEl 300 300×300×400 0.30mm High-definition molding is enabled by adopting the 0.3 mm CO2 laser beam diameter. This product targets such markets as electronic devices and computers.
RaFaEl 150 150×150×200 0.18mm The CO2 laser beam diameter was downsized to 0.18 mm to enable further high-definition molding by decreasing the work size.
door panel instrument panel
The door panel and instrument panel were made by polishing and painting the form that were molded by the 3D printer. They both are made of nylon12.
Accord PHV Samples made of titanium alloy
Intake manifold that was molded by the 3D printer. It is made of nylon12 added with carbon fiber. It has high-strength and high-heat distortion temperature. Samples made of titanium alloy that was molded by the 3D printer

 

Koiwai

Koiwai established the 3D Printer Laminated Sand Mold Casting Service Bureau in 2007. The 3D printer can give shape to sand molds in one-third of the time shorter than the conventional sand mold manufacturing method. The company supplies samples to IHI and Mitsubishi Heavy Industries.
The company also provides metallic powder laminate casting services using a metal powder laminate casting system. It is currently entrusted with services for testing laboratories.
Laminated sand mold sample Metallic powder laminate samples
Laminated sand mold sample Metallic powder laminate samples

 

Altech

Altech is a sales agent in Japan for the 3D printer manufacturer, Stratasys, which is headquartered in the U.S. and Israel. Stratasys sells 3D printers that are based on two different methods.
The first method is the OBJET series, which is based on the polyjet system. This system molds products by jetting fluid resin to every layer and curing it with an ultraviolet lamp. It enables fine molding at the smallest lamination pitch of 16 microns. It also enables simultaneous use of two different resins. It is compatible with rubber, ABS, and PP. As a weak point, the modeled products are weak to heat and softness.
The second is the FORTUS series, which is based on the Fused Deposition Modeling (FDM). This system models a three-dimensional shape by laminating a thermoplastic resin dissolved into a semiliquid state. This system can model solid component parts by using an industrial thermoplastic resin.
Prototype developed by the OBJET series Prototype lamp cover using the FORTUS series
Prototype developed by the OBJET series, which is based on the polyjet system. The prototype expresses bones in the transparent palm by using two kinds of resins. Prototype lamp cover using the FORTUS series, which is based on the FDM system. It is made of a translucent ABS resin.
Functional prototype of a child seat
Functional prototype of a child seat using the FORTUS series. It was modeled from a resin sheet of 91×61×91 cm.

 

CMET

CMET sells a rapid prototyping device called Rapid Meister. The device molds a three-dimensional object by irradiating a liquid photo-curable resin with an ultraviolet ray laser to solidify it layer by layer. The company developed a heat-resistant transparent resin used for this rapid prototyping device (TSR-884). The resin will be used to rapid-prototype a transparent engine block model for analysis of the liquid flow inside it.
The company also developed a casting method substituting the lost-wax method called the "Rapid Prototyping Precision Casting Method." This method develops a mold by preparing a master model by rapid prototyping using TSR-883, which is a resin that gasifies after burning without leaving ash. According to CMET, this method dispenses with the manufacturing of the mold that is required in the lost-wax method and thus enables considerable reduction of costs and lead time, especially in small-lot production.
Engine block made of a transparent heat-resistant resin Car lamp made of a transparent heat-resistant resin
Engine block made of a transparent heat-resistant resin. It is used as a model for shape analysis and functional assessment. Car lamp made of a transparent heat-resistant resin
Master models (transparent) and casting components (gray)
Master models (transparent) and casting components (gray) that were developed by the rapid prototyping precision casting method

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