Short description about aluminum alloy sand casting

 

Sand casting has been used for centuries for most popular and simplest types of castings. Sand casting could be used to small and large parts, main steps include drawing confirmation, mould, core-making, modeling, melting and pouring, heat treatment, cleaning, blasting, machining,  surface coating, and so on.

Drawing confirm 

The traditional method is to obtain the casting drawings and send them to the foundry. This process can be completed in the quotation. Nowadays, more and more customers and foundries use computer-aided design instead, and its good for quotation by drawing in stp, x_t, pdf, cad, igs, etc. Also make supplier know the qty, material type, like in A356, alsi7mg, etc. (for sand casting aluminum material is even same like low pressure casting )

Following is common aluminum alloy sand casting material types:

China GB ISO JIS EN NF DIN BS UNI              USA
Grade Code AA SAE
AlSi7Mg ZL101 AlSi7Mg AC4C ENAC-42100 A-S7G AlSi7Mg LM25 3599 356 323
ZAlSi7MgA ZL101A AlSi7Mg AC4CH ENAC-42100 A-S7G03 AlSi7Mg(3.2371) 2L99 8024 A356.0 336
ZAlSi12 ZL102 AlSi12 AC3A ENAC-44100 A-S13 AlSi12(3.2581) LM6 4514 413.0 b413.0 305
ZAlSi9Mg ZL104 AlSi10Mg AC4A ENAC-43300 A-S9G A-S10G AlSi9Mg(3.2373) LM9 3051 360 309
ZAlSi7Cu4 ZL107 AlSi6Cu4 AC2B ENAC-45000 A-S5UZ AlSi6Cu4(3.2151) LM21 Apr-69 319 326
ZL302 ZL6 A05140 AC7A A05141 AlMg6/AlMg3 514

 

Mold:

In sand casting, moulds are made of wood and inner metal materials. In this process, we require our engineers to make the die size slightly larger than the finished product, and the difference is called shrinkage margin. The aim is to ensure the solidification and shrinkage of molten metal by the action of molten metal on the die, to prevent voids in the casting process.

Core making:

Core-making requires placing resin sand grains in the die to form internal surface castings. Therefore, the gap between the core and the die eventually becomes casting.

Forming

A set of moulds should be prepared during the melting process. Forming usually involves the support frame of the die, pulling melted aluminum into die, melting the previously placed core in the die and closing the die.

clean/blasting

The purpose of cleaning is to remove sand grains, grinding and excess metals in castings. Welding and sand removal can improve the surface appearance of castings

The burned sand core and scale were removed to improve the surface appearance of casting. Excess metal and other risers were removed. The next step is welding and grinding. Finally, check defects and comprehensive quality. Blasting, is a must step and free step for every part to get smooth and beautiful surface.

Heat treating, machining, coating, etc

Reprocessing(Heat treating, machining, coating, etc) before shipment. According to the requirements of different customers, we can do heat treatment, machining, surface treatment, additional inspection and so on.

 

Sand casting part usually are some big part, like some pump body, frame,  base, big wheel, etc.

But now, more and more sand casting parts are choosing low pressure casting, as low pressure casting could share more advantages.

 

landscape casting alu furniture

sand casting