Common defects of titanium castings
1 titanium casting is incomplete
Incomplete titanium castings related to the following reasons:
1). Casting machine models and casting flow rate is closely tied, but also with the casting machine vacuum, inert gas flow.
2). Casting set too small, too long, set the location, wax too lean can affect the integrity of the castings.
3). Exhaust channel settings of Titanium in the melting process is inert gas protection. Inert gas will enter the mold cavity. When the molten titanium is injected into the mold cavity, the gas in the small part of the cavity hinders the inflow of the titanium liquid and forms the pores. Common in the snap ring tip. Therefore, the mold set on the casting mold
At the same time, we must carefully set the exhaust duct or storage balloon.
4). Mold temperature is high, castings fewer defects, but the casting surface contaminated layer thickness, poor mechanical properties. Reduce the mold temperature can reduce the surface pollution, but more castings weaknesses. Mold for 350 ~ 400 can reduce pollution, but also reduce casting defects.
5). The amount of titanium to be produced castings as well large, while the amount of titanium is not enough, the inevitable casting incomplete.
2 titanium castings internal porosity
1). The presence of pores in the titanium castings is due to the titanium casting liquid into the mold cavity. The inert gas and the residual air in the melting cavity and the mold cavity are then entangled in the cavity, and the titanium liquid forms a condensed shell immediately when it is put into the cavity. Involved in the gas cannot escape the formation of castings inside the pores. The number and type of stomatal formation are device dependent. Pressurized, attractive and pressurized (non-attractive) -type pores formed were dispersed. Pressurized (unattractive) forms fewer pores than pressurized suction. Centrifugal titanium casting machine stomatal mostly in the proximal end of the rotating body, and the incidence of stomatal significantly less than the pressurized suction type and pressure type.
2). The permeability of the embedding material is also associated with the stomata. Breathable embedding material for pressure, suction type titanium casting machine can produce more pores. Centrifugal casting titanium machine and embedded, material permeability has nothing to do. In addition, with the spur, the location of the exhaust path also has a definite relationship.
3 titanium castings rough surface
Casting surface roughness refers to the surface uneven, or flow marks. Forming reason may be due to the mold temperature is too high, embedded material and titanium liquid sintering reaction may also be due to mold rupture, sticky sand. Or owing to the quality of embedding material.
4 titanium casting surface contaminated layer is too thick
There are many factors that determine the thickness of the pollution layer on the surface of titanium castings, such as the type of embedded material, mold temperature, vacuum degree of equipment, and purity of the inert gas. Types of embedded materials on the thickness of the impact of pollution rules are as follows: Zirconia-based embedded material thinnest, according to alumina, magnesium oxide, phosphate-based embedded material order thickening of the contaminated layer.
1 titanium casting is incomplete
Incomplete titanium castings related to the following reasons:
1). Casting machine models and casting flow rate is closely tied, but also with the casting machine vacuum, inert gas flow.
2). Casting set too small, too long, set the location, wax too lean can affect the integrity of the castings.
3). Exhaust channel settings of Titanium in the melting process is inert gas protection. Inert gas will enter the mold cavity. When the molten titanium is injected into the mold cavity, the gas in the small part of the cavity hinders the inflow of the titanium liquid and forms the pores. Common in the snap ring tip. Therefore, the mold set on the casting mold
At the same time, we must carefully set the exhaust duct or storage balloon.
4). Mold temperature is high, castings fewer defects, but the casting surface contaminated layer thickness, poor mechanical properties. Reduce the mold temperature can reduce the surface pollution, but more castings weaknesses. Mold for 350 ~ 400 can reduce pollution, but also reduce casting defects.
5). The amount of titanium to be produced castings as well large, while the amount of titanium is not enough, the inevitable casting incomplete.
2 titanium castings internal porosity
1). The presence of pores in the titanium castings is due to the titanium casting liquid into the mold cavity. The inert gas and the residual air in the melting cavity and the mold cavity are then entangled in the cavity, and the titanium liquid forms a condensed shell immediately when it is put into the cavity. Involved in the gas cannot escape the formation of castings inside the pores. The number and type of stomatal formation are device dependent. Pressurized, attractive and pressurized (non-attractive) -type pores formed were dispersed. Pressurized (unattractive) forms fewer pores than pressurized suction. Centrifugal titanium casting machine stomatal mostly in the proximal end of the rotating body, and the incidence of stomatal significantly less than the pressurized suction type and pressure type.
2). The permeability of the embedding material is also associated with the stomata. Breathable embedding material for pressure, suction type titanium casting machine can produce more pores. Centrifugal casting titanium machine and embedded, material permeability has nothing to do. In addition, with the spur, the location of the exhaust path also has a definite relationship.
3 titanium castings rough surface
Casting surface roughness refers to the surface uneven, or flow marks. Forming reason may be due to the mold temperature is too high, embedded material and titanium liquid sintering reaction may also be due to mold rupture, sticky sand. Or owing to the quality of embedding material.
4 titanium casting surface contaminated layer is too thick
There are many factors that determine the thickness of the pollution layer on the surface of titanium castings, such as the type of embedded material, mold temperature, vacuum degree of equipment, and purity of the inert gas. Types of embedded materials on the thickness of the impact of pollution rules are as follows: Zirconia-based embedded material thinnest, according to alumina, magnesium oxide, phosphate-based embedded material order thickening of the contaminated layer.
