There are three main forms of die casting mold failure

1 thermal fatigue crack damage failure

Thermal fatigue cracking failure of die casting mold production, mold repeatedly stimulated cooling and heating effect, the molding surface and internal deformation are involved, and the repeated cycles of thermal stress, leading to tissue structure of two injuries and loss of toughness, causing cracks appeared, and continue to expand, once a crack expanding, and molten metal liquid impact, coupled with repeated mechanical stress crack accelerated expansion. Therefore, on one hand, the casting mold must be fully preheated starting. In addition, in the production of the die casting die in must be kept in a certain temperature range, so as to avoid the early cracking. At the same time, to ensure the mold production and manufacturing of internal no problem. Because of the practical production, the majority of the ineffectiveness of the die thermal fatigue cracking.

zinc die casting
zinc die casting

2 invalidity

Fracture failure of the shot under the action of force, die in the weak point of crack, especially the molding surface scribing traces or electric machining marks are not polished optically, or molded clear corner will appear first fine crack, when the grain boundary exists brittle phase or coarse grains, which is easy to break. And brittle fracture crack growth quickly, the die casting mold invalidity is very dangerous factors. Therefore, on one hand, where mold surface scratches, electric machining marks must be polished light, Zinc Die Casting even when it is in the gating system position, must also be polished. Additional requirements by use of the mold material of high strength, good plasticity, impact toughness, and fracture toughness were good.

3 corrosion failure

Molten failure previously said, conventional die casting alloy zinc alloy, aluminum alloy, magnesium alloy, and copper alloy, but also pure aluminum die-casting, Zn, Al, Mg is the more active metal elements, they and the die materials has the good affinity, especially Al easy to bite mold. When the mold hardness is high, then the corrosion resistance is better, and the molding surface if the soft point, then on the corrosion resistance of adverse.

The die failure of many factors, both external factors (for example, whether the mold casting temperature preheating, water paint spraying quantity, die casting machine, die size matching tonnage, high-pressure gate speed too fast, cooling water open and die-casting production synchronization, casting materials and components, the discretion of Fe the casting dimension shape, size, wall thickness of coating type, etc. ). There are internal ( cases of mold material metallurgical quality, blank forging process, the mold structure and the rationality of the design of gating system, the rationality of the design, mold machine ( EDM ) generated during the processing of internal stress, the mold heat treatment technology, including a variety of matching precision and smoothness requirements ). Die if the early failure, need to find out what the internal or external, for future improvement. But in actual production, corrosion is only die locally, cases of gate directly flushing part ( core, cavity) prone to corrosion phenomenon, and the hardness is easy to appear soft aluminum Alloy Die Casting adhesive die

New material of aluminum alloy

Yesterday, the reporter learned from Shanghai Academy of Spaceflight Technology, the hospital in Temple One goal of the task assumed aircraft cabin structure and assembly of resources, power sub-systems, docking mechanism subsystem, control and communication subsystems supporting stand-alone subsystems and overall circuit Resource module cable network research task.

Resource tank “fuel” an increase in total weight was reduced by 10%

Temple One of the energy as a source of resources and power module, and the JEM to be connected with the launch vehicle, in addition to ensuring a reliable connection, the cabin is also equipped with a number of subsystems within and outside the nearly 200 sets of equipment and a large pipe, cable and so on. The structure of the resource module design, installation and testing have brought a lot of problems. Development process with a large number of new technologies, new processes.

aluminium die casting
aluminium die casting

Designed from the start, the resource module is facing, “weight” problem. Because the resources to carry a propellant tank before the Shenzhou spacecraft than an increase of 50% or more, but the construction of the main cabin still hopes for the implementation of weight loss. In this way, before the use of aluminum is difficult to meet the requirements, the first use of aluminum-lithium alloy as the raw material, 10% of successful weight loss for the cabin.

In order to maintain long-term in-orbit requirements of the target aircraft, the entire device carried by the lofty air and oxygen-carrying capacity of a single spacecraft, for environmental control and life support sub-system uses a large-capacity high-pressure composite cylinder for gas storage. It is reported that the inflatable cylinders before and after the change in the direction of larger diameter, the resource module assembly with a certain flexibility in design of cylinders installed bands, difficult to install to solve the problem of the cylinder, greatly reducing the weight of the cylinder mounting bracket for the entire device contributed to weight loss. Aluminium die Casting Heating parts

Power solar “wings” using new technology

For manned space flight, the aircraft power subsystem has always been the lifeline.

This time, Temple One pressure on the semi-rigid solar wing, the technology of China’s first spacecraft power subsystem applications. Externally, two solar wings like a pair of “wings” covered with horizontal black solar film, artful. The face of low-orbit space station environment, before the full use of high-orbiting satellites, are obviously not applicable to rigid panels. After a number of technology experiments, researchers identified the Shanghai grid panels with fiberglass glue and glue concentration in the actual operation and other parameters to determine the carbon-fiber frame with glass fiber mesh of semi-rigid structure.

Butt has gone through 16 years of R & D away

For eight and Temple of God “space Kiss”, Shanghai Academy of Spaceflight Technology 805 development team started from 1995, Principles of docking technology, simulation to explore, to create in 1999 a first prototype of 1:1, from 2000, ten key technology component-level research, developed in 2002 for engineering applications of docking mechanism and the four large-scale research prototype system-level ground simulation test equipment, docking mechanism 2005, sub-systems from the official project to be completed in December 2009 initial research into the positive kind of work, completed in November 2010 is kind of product development to deliver, to the range of 2011 to the base test, the 16-year road to product development from scratch, Aluminum Casting Anodized from there to fine, docking points The journey continues … the system …