Aluminum alloy profiles because of its small density, high specific strength, high temperature resistance, good oxidation resistance and other characteristics, widely used. However, aluminum alloy profiles poor machining performance, the impact of widespread use of this material.

Aluminum alloy profiles that titanium alloying elements in the industry in order to improve the strength of titanium. Titanium can be divided into three kinds: a titanium alloy, b and a + b titanium alloy titanium alloy. Titanium is ab and b by a two-phase composition, these alloys organizational stability, high temperature deformation properties, toughness, ductility is good enough for quenching, aging treatment, the alloy strengthening. Performance characteristics of titanium alloy mainly in:

1) high specific strength. Aluminum alloy profiles density (4.4kg / dm3) light weight, but its strength was greater than the ultra-high-strength steel.

2) high heat resistance. Good thermal stability aluminum alloy profiles at 300 ~ 500 ℃ condition, its strength is about 10 times higher than aluminum.

3) large chemical activity. Titanium can produce a strong chemical reaction with oxygen in air, nitrogen, carbon monoxide, water vapor and other substances, TiC and TiN at the surface hardened layer.

Poor thermal conductivity. Poor thermal conductivity of titanium, titanium alloy TC4 at 200 ℃ thermal conductivity l = 16.8W / m • ℃, the thermal conductivity is 0.036 cal / cm • s • ℃.

Machined aluminum alloy profiles characteristic analysis

First, titanium low thermal conductivity, is only a quarter of steel, aluminum 1/13, copper 1/25. Cutting zone due to slow cooling, is not conducive to thermal equilibrium, in the cutting process, the cooling and the cooling effect is poor, easy to form a high temperature in the cutting zone, springback deformation after machining large parts, resulting in a torque increase of the cutting tool, the cutting edge wear faster, durability decreases. Second, the low thermal conductivity of titanium, so cutting heat accumulation in the small area around the cutting knife is not easy to distribute, rake increase friction, easy chip removal, cutting heat is not easy to distribute and accelerate tool wear. Finally, the high chemical activity of titanium alloys in high temperature processing easy and tool materials react to form insoluble deposited, diffusion, resulting in sticky knife, burning knife, cutting knife and so on.

Tool material selection should meet the following requirements:

• sufficient hardness. The tool must be much larger than the hardness of aluminum alloy hardness.

• sufficient strength and toughness. Since the tool under a lot of torque and cutting forces when cutting aluminum alloy, it must have sufficient strength and toughness.

• sufficient abrasion resistance. Because of good titanium toughness to a sharp cutting edge during machining, tool material and therefore must have sufficient wear resistance, so as to reduce work hardening. It is important to choose the parameters of the tool machining titanium.

• Tool materials and titanium affinity ability to worse. Due to the high chemical activity of aluminum alloy, so to avoid the formation of tool material and dissolved aluminum alloy cladding, diffusion from the alloy, resulting in sticky knife, burning knife phenomenon.

After cutting tool materials commonly used for domestic and foreign tool materials tested showed high cobalt tool desired effect, the main effect of cobalt can strengthen the secondary hardening effect, raise red hardness and hardness after heat treatment, but also has a high toughness, wear , good heat dissipation, more suitable for machining aluminum alloy profiles.