Actual case
Titanium alloy parts
(1) The material is TC4 titanium alloy. TC4 titanium alloy has a series of advantages such as good comprehensive mechanical properties, excellent corrosion resistance, small density, high specific strength, better toughness and weldability, etc. The aerospace, petrochemical, shipbuilding, automotive, pharmaceutical and other sectors have all been successfully applied.
（2）Features
1. The internal milling groove of the product is welded, resulting in a minimum wall thickness of 1mm, which is easy to deform and vibrate.
2. The front and both sides of the product have many related dimensions and are interlocking.
3. Size ∅8(0~+0.022) x109 and 2-8(0~+0.02)x36 need to be processed at one time.
4. More threads, not easy to process
5. No liquid and waste can enter inside
6. There is a requirement for concentricity and cannot be processed at one time
（3）Solution
1. A four-axis bridge is used to fix the jig, and the jig is used to fix the bottom of the workpiece with pins and screws. First, perform symmetrical rough machining on both sides of the workpiece, with a reserve of 0.5MM. Then carry out the front rough machining to make the overall shape of the workpiece appear.
2. ∅8 precision holes are processed by manually rotating the jig 90 degrees. Because the fine hole is very deep and the middle is broken, it is necessary to first process the upper fine hole to the number, then process the lower fine hole, and then use the full-blade reamer for fine twisting.
3. The thread is milled with a special thread milling cutter to ensure stability and consistency.
4. Before processing, use nylon to block the vent hole, and then apply sealant to ensure that no liquid enters the interior.
5. The bottom processing outer circle is processed based on the front center through hole to ensure a concentricity of 0.03.
（4）Testing method
1. Each process adopts special measuring tools and needle gauges for full inspection, and the degree of symmetry adopts two-way inspection of altimeter and projector.
2. Concentricity production tooling measuring tool testing.
3. The thread is fully inspected using standard thread inspection gauges.
